mirror of https://gitee.com/openkylin/linux.git
x86: prepare kprobes code for x86 unification
This patch cleanup kprobes code on x86 for unification. This patch is based on Arjan's previous work. - Remove spurious whitespace changes - Add harmless includes - Make the 32/64 files more identical - Generalize structure fields' and local variable name. - Wrap accessing to stack address by macros. - Modify bitmap making macro. - Merge fixup code into is_riprel() and change its name to fix_riprel(). - Set MAX_INSN_SIZE to 16 on both arch. - Use u32 for bitmaps on both architectures. - Clarify some comments. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Arjan van de Ven <arjan@infradead.org> Signed-off-by: Jim Keniston <jkenisto@us.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Masami Hiramatsu
Ingo Molnar
parent
da07ab0375
commit
8533bbe9f8
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@ -29,10 +29,15 @@
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#include <linux/kprobes.h>
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#include <linux/ptrace.h>
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#include <linux/string.h>
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#include <linux/slab.h>
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#include <linux/preempt.h>
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#include <linux/module.h>
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#include <linux/kdebug.h>
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#include <asm/cacheflush.h>
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#include <asm/desc.h>
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#include <asm/pgtable.h>
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#include <asm/uaccess.h>
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#include <asm/alternative.h>
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@ -41,31 +46,17 @@ void jprobe_return_end(void);
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DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
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DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
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struct kretprobe_blackpoint kretprobe_blacklist[] = {
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{"__switch_to", }, /* This function switches only current task, but
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doesn't switch kernel stack.*/
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{NULL, NULL} /* Terminator */
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};
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const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist);
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/* insert a jmp code */
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static __always_inline void set_jmp_op(void *from, void *to)
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{
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struct __arch_jmp_op {
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char op;
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long raddr;
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} __attribute__((packed)) *jop;
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jop = (struct __arch_jmp_op *)from;
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jop->raddr = (long)(to) - ((long)(from) + 5);
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jop->op = RELATIVEJUMP_INSTRUCTION;
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}
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/*
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* returns non-zero if opcodes can be boosted.
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* "®s->sp" looks wrong, but it's correct for x86_32. x86_32 CPUs
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* don't save the ss and esp registers if the CPU is already in kernel
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* mode when it traps. So for kprobes, regs->sp and regs->ss are not
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* the [nonexistent] saved stack pointer and ss register, but rather
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* the top 8 bytes of the pre-int3 stack. So ®s->sp happens to
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* point to the top of the pre-int3 stack.
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*/
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static __always_inline int can_boost(kprobe_opcode_t *opcodes)
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{
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#define W(row,b0,b1,b2,b3,b4,b5,b6,b7,b8,b9,ba,bb,bc,bd,be,bf) \
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#define stack_addr(regs) ((unsigned long *)®s->sp)
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#define W(row, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf)\
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(((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \
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(b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) | \
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(b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) | \
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@ -73,33 +64,103 @@ static __always_inline int can_boost(kprobe_opcode_t *opcodes)
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<< (row % 32))
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/*
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* Undefined/reserved opcodes, conditional jump, Opcode Extension
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* Groups, and some special opcodes can not be boost.
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* Groups, and some special opcodes can not boost.
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*/
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static const unsigned long twobyte_is_boostable[256 / 32] = {
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/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
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/* ------------------------------- */
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W(0x00, 0,0,1,1,0,0,1,0,1,1,0,0,0,0,0,0)| /* 00 */
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W(0x10, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0), /* 10 */
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W(0x20, 1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0)| /* 20 */
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W(0x30, 0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0), /* 30 */
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W(0x40, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* 40 */
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W(0x50, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0), /* 50 */
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W(0x60, 1,1,1,1,1,1,1,1,1,1,1,1,0,0,1,1)| /* 60 */
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W(0x70, 0,0,0,0,1,1,1,1,0,0,0,0,0,0,1,1), /* 70 */
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W(0x80, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)| /* 80 */
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W(0x90, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1), /* 90 */
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W(0xa0, 1,1,0,1,1,1,0,0,1,1,0,1,1,1,0,1)| /* a0 */
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W(0xb0, 1,1,1,1,1,1,1,1,0,0,0,1,1,1,1,1), /* b0 */
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W(0xc0, 1,1,0,0,0,0,0,0,1,1,1,1,1,1,1,1)| /* c0 */
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W(0xd0, 0,1,1,1,0,1,0,0,1,1,0,1,1,1,0,1), /* d0 */
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W(0xe0, 0,1,1,0,0,1,0,0,1,1,0,1,1,1,0,1)| /* e0 */
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W(0xf0, 0,1,1,1,0,1,0,0,1,1,1,0,1,1,1,0) /* f0 */
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/* ------------------------------- */
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/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
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};
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static const u32 twobyte_is_boostable[256 / 32] = {
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/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
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/* ---------------------------------------------- */
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W(0x00, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0) | /* 00 */
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W(0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 10 */
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W(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 20 */
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W(0x30, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 30 */
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W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 40 */
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W(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 50 */
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W(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1) | /* 60 */
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W(0x70, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) , /* 70 */
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W(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 80 */
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W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 90 */
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W(0xa0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) | /* a0 */
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W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) , /* b0 */
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W(0xc0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) | /* c0 */
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W(0xd0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) , /* d0 */
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W(0xe0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) | /* e0 */
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W(0xf0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0) /* f0 */
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/* ----------------------------------------------- */
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/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
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};
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static const u32 onebyte_has_modrm[256 / 32] = {
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/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
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/* ----------------------------------------------- */
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W(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* 00 */
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W(0x10, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) , /* 10 */
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W(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* 20 */
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W(0x30, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) , /* 30 */
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W(0x40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 40 */
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W(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 50 */
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W(0x60, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0) | /* 60 */
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W(0x70, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 70 */
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W(0x80, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 80 */
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W(0x90, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 90 */
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W(0xa0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* a0 */
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W(0xb0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* b0 */
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W(0xc0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) | /* c0 */
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W(0xd0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) , /* d0 */
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W(0xe0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* e0 */
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W(0xf0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) /* f0 */
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/* ----------------------------------------------- */
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/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
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};
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static const u32 twobyte_has_modrm[256 / 32] = {
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/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
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/* ----------------------------------------------- */
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W(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1) | /* 0f */
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W(0x10, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0) , /* 1f */
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W(0x20, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1) | /* 2f */
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W(0x30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 3f */
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W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 4f */
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W(0x50, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 5f */
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W(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 6f */
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W(0x70, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1) , /* 7f */
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W(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 8f */
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W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 9f */
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W(0xa0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) | /* af */
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W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1) , /* bf */
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W(0xc0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) | /* cf */
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W(0xd0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* df */
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W(0xe0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* ef */
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W(0xf0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0) /* ff */
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/* ----------------------------------------------- */
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/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
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};
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#undef W
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struct kretprobe_blackpoint kretprobe_blacklist[] = {
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{"__switch_to", }, /* This function switches only current task, but
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doesn't switch kernel stack.*/
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{NULL, NULL} /* Terminator */
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};
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const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist);
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/* Insert a jump instruction at address 'from', which jumps to address 'to'.*/
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static __always_inline void set_jmp_op(void *from, void *to)
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{
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struct __arch_jmp_op {
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char op;
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s32 raddr;
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} __attribute__((packed)) * jop;
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jop = (struct __arch_jmp_op *)from;
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jop->raddr = (s32)((long)(to) - ((long)(from) + 5));
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jop->op = RELATIVEJUMP_INSTRUCTION;
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}
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/*
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* returns non-zero if opcode is boostable.
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*/
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static __always_inline int can_boost(kprobe_opcode_t *opcodes)
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{
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kprobe_opcode_t opcode;
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kprobe_opcode_t *orig_opcodes = opcodes;
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retry:
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if (opcodes - orig_opcodes > MAX_INSN_SIZE - 1)
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return 0;
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@ -109,7 +170,8 @@ static __always_inline int can_boost(kprobe_opcode_t *opcodes)
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if (opcode == 0x0f) {
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if (opcodes - orig_opcodes > MAX_INSN_SIZE - 1)
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return 0;
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return test_bit(*opcodes, twobyte_is_boostable);
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return test_bit(*opcodes,
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(unsigned long *)twobyte_is_boostable);
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}
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switch (opcode & 0xf0) {
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@ -132,12 +194,13 @@ static __always_inline int can_boost(kprobe_opcode_t *opcodes)
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case 0xf0:
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if ((opcode & 0x0c) == 0 && opcode != 0xf1)
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goto retry; /* lock/rep(ne) prefix */
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/* clear and set flags can be boost */
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/* clear and set flags are boostable */
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return (opcode == 0xf5 || (0xf7 < opcode && opcode < 0xfe));
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default:
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/* segment override prefixes are boostable */
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if (opcode == 0x26 || opcode == 0x36 || opcode == 0x3e)
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goto retry; /* prefixes */
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/* can't boost CS override and call */
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/* CS override prefix and call are not boostable */
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return (opcode != 0x2e && opcode != 0x9a);
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}
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}
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@ -145,9 +208,9 @@ static __always_inline int can_boost(kprobe_opcode_t *opcodes)
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/*
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* returns non-zero if opcode modifies the interrupt flag.
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*/
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static int __kprobes is_IF_modifier(kprobe_opcode_t opcode)
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static int __kprobes is_IF_modifier(kprobe_opcode_t *insn)
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{
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switch (opcode) {
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switch (*insn) {
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case 0xfa: /* cli */
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case 0xfb: /* sti */
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case 0xcf: /* iret/iretd */
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@ -157,20 +220,24 @@ static int __kprobes is_IF_modifier(kprobe_opcode_t opcode)
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return 0;
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}
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static void __kprobes arch_copy_kprobe(struct kprobe *p)
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{
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memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
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if (can_boost(p->addr))
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p->ainsn.boostable = 0;
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else
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p->ainsn.boostable = -1;
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p->opcode = *p->addr;
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}
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int __kprobes arch_prepare_kprobe(struct kprobe *p)
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{
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/* insn: must be on special executable page on i386. */
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/* insn: must be on special executable page on x86. */
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p->ainsn.insn = get_insn_slot();
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if (!p->ainsn.insn)
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return -ENOMEM;
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memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
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p->opcode = *p->addr;
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if (can_boost(p->addr)) {
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p->ainsn.boostable = 0;
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} else {
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p->ainsn.boostable = -1;
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}
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arch_copy_kprobe(p);
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return 0;
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}
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@ -195,26 +262,26 @@ static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
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{
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kcb->prev_kprobe.kp = kprobe_running();
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kcb->prev_kprobe.status = kcb->kprobe_status;
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kcb->prev_kprobe.old_eflags = kcb->kprobe_old_eflags;
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kcb->prev_kprobe.saved_eflags = kcb->kprobe_saved_eflags;
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kcb->prev_kprobe.old_flags = kcb->kprobe_old_flags;
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kcb->prev_kprobe.saved_flags = kcb->kprobe_saved_flags;
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}
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static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
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{
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__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
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kcb->kprobe_status = kcb->prev_kprobe.status;
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kcb->kprobe_old_eflags = kcb->prev_kprobe.old_eflags;
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kcb->kprobe_saved_eflags = kcb->prev_kprobe.saved_eflags;
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kcb->kprobe_old_flags = kcb->prev_kprobe.old_flags;
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kcb->kprobe_saved_flags = kcb->prev_kprobe.saved_flags;
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}
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static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
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struct kprobe_ctlblk *kcb)
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{
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__get_cpu_var(current_kprobe) = p;
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kcb->kprobe_saved_eflags = kcb->kprobe_old_eflags
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kcb->kprobe_saved_flags = kcb->kprobe_old_flags
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= (regs->flags & (TF_MASK | IF_MASK));
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if (is_IF_modifier(p->opcode))
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kcb->kprobe_saved_eflags &= ~IF_MASK;
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if (is_IF_modifier(p->ainsn.insn))
|
||||
kcb->kprobe_saved_flags &= ~IF_MASK;
|
||||
}
|
||||
|
||||
static __always_inline void clear_btf(void)
|
||||
|
|
@ -245,7 +312,7 @@ static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
|
|||
void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
|
||||
struct pt_regs *regs)
|
||||
{
|
||||
unsigned long *sara = (unsigned long *)®s->sp;
|
||||
unsigned long *sara = stack_addr(regs);
|
||||
|
||||
ri->ret_addr = (kprobe_opcode_t *) *sara;
|
||||
|
||||
|
|
@ -280,7 +347,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
|
|||
if (kcb->kprobe_status == KPROBE_HIT_SS &&
|
||||
*p->ainsn.insn == BREAKPOINT_INSTRUCTION) {
|
||||
regs->flags &= ~TF_MASK;
|
||||
regs->flags |= kcb->kprobe_saved_eflags;
|
||||
regs->flags |= kcb->kprobe_saved_flags;
|
||||
goto no_kprobe;
|
||||
}
|
||||
/* We have reentered the kprobe_handler(), since
|
||||
|
|
@ -301,7 +368,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
|
|||
* another cpu right after we hit, no further
|
||||
* handling of this interrupt is appropriate
|
||||
*/
|
||||
regs->ip -= sizeof(kprobe_opcode_t);
|
||||
regs->ip = (unsigned long)addr;
|
||||
ret = 1;
|
||||
goto no_kprobe;
|
||||
}
|
||||
|
|
@ -325,7 +392,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
|
|||
* Back up over the (now missing) int3 and run
|
||||
* the original instruction.
|
||||
*/
|
||||
regs->ip -= sizeof(kprobe_opcode_t);
|
||||
regs->ip = (unsigned long)addr;
|
||||
ret = 1;
|
||||
}
|
||||
/* Not one of ours: let kernel handle it */
|
||||
|
|
@ -341,7 +408,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
|
|||
|
||||
ss_probe:
|
||||
#if !defined(CONFIG_PREEMPT) || defined(CONFIG_PM)
|
||||
if (p->ainsn.boostable == 1 && !p->post_handler){
|
||||
if (p->ainsn.boostable == 1 && !p->post_handler) {
|
||||
/* Boost up -- we can execute copied instructions directly */
|
||||
reset_current_kprobe();
|
||||
regs->ip = (unsigned long)p->ainsn.insn;
|
||||
|
|
@ -359,16 +426,18 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
|
|||
}
|
||||
|
||||
/*
|
||||
* For function-return probes, init_kprobes() establishes a probepoint
|
||||
* here. When a retprobed function returns, this probe is hit and
|
||||
* trampoline_probe_handler() runs, calling the kretprobe's handler.
|
||||
* When a retprobed function returns, this code saves registers and
|
||||
* calls trampoline_handler() runs, which calls the kretprobe's handler.
|
||||
*/
|
||||
void __kprobes kretprobe_trampoline_holder(void)
|
||||
{
|
||||
asm volatile ( ".global kretprobe_trampoline\n"
|
||||
"kretprobe_trampoline: \n"
|
||||
" pushf\n"
|
||||
/* skip cs, ip, orig_ax */
|
||||
/*
|
||||
* Skip cs, ip, orig_ax.
|
||||
* trampoline_handler() will plug in these values
|
||||
*/
|
||||
" subl $12, %esp\n"
|
||||
" pushl %fs\n"
|
||||
" pushl %ds\n"
|
||||
|
|
@ -382,10 +451,10 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
|
|||
" pushl %ebx\n"
|
||||
" movl %esp, %eax\n"
|
||||
" call trampoline_handler\n"
|
||||
/* move flags to cs */
|
||||
/* Move flags to cs */
|
||||
" movl 52(%esp), %edx\n"
|
||||
" movl %edx, 48(%esp)\n"
|
||||
/* save true return address on flags */
|
||||
/* Replace saved flags with true return address. */
|
||||
" movl %eax, 52(%esp)\n"
|
||||
" popl %ebx\n"
|
||||
" popl %ecx\n"
|
||||
|
|
@ -394,16 +463,16 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
|
|||
" popl %edi\n"
|
||||
" popl %ebp\n"
|
||||
" popl %eax\n"
|
||||
/* skip ip, orig_ax, es, ds, fs */
|
||||
/* Skip ip, orig_ax, es, ds, fs */
|
||||
" addl $20, %esp\n"
|
||||
" popf\n"
|
||||
" ret\n");
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Called from kretprobe_trampoline
|
||||
*/
|
||||
void *__kprobes trampoline_handler(struct pt_regs *regs)
|
||||
void * __kprobes trampoline_handler(struct pt_regs *regs)
|
||||
{
|
||||
struct kretprobe_instance *ri = NULL;
|
||||
struct hlist_head *head, empty_rp;
|
||||
|
|
@ -417,27 +486,27 @@ void *__kprobes trampoline_handler(struct pt_regs *regs)
|
|||
/* fixup registers */
|
||||
regs->cs = __KERNEL_CS | get_kernel_rpl();
|
||||
regs->ip = trampoline_address;
|
||||
regs->orig_ax = 0xffffffff;
|
||||
regs->orig_ax = ~0UL;
|
||||
|
||||
/*
|
||||
* It is possible to have multiple instances associated with a given
|
||||
* task either because an multiple functions in the call path
|
||||
* have a return probe installed on them, and/or more then one return
|
||||
* task either because multiple functions in the call path have
|
||||
* return probes installed on them, and/or more then one
|
||||
* return probe was registered for a target function.
|
||||
*
|
||||
* We can handle this because:
|
||||
* - instances are always inserted at the head of the list
|
||||
* - instances are always pushed into the head of the list
|
||||
* - when multiple return probes are registered for the same
|
||||
* function, the first instance's ret_addr will point to the
|
||||
* real return address, and all the rest will point to
|
||||
* kretprobe_trampoline
|
||||
* function, the (chronologically) first instance's ret_addr
|
||||
* will be the real return address, and all the rest will
|
||||
* point to kretprobe_trampoline.
|
||||
*/
|
||||
hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
|
||||
if (ri->task != current)
|
||||
/* another task is sharing our hash bucket */
|
||||
continue;
|
||||
|
||||
if (ri->rp && ri->rp->handler){
|
||||
if (ri->rp && ri->rp->handler) {
|
||||
__get_cpu_var(current_kprobe) = &ri->rp->kp;
|
||||
get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
|
||||
ri->rp->handler(ri, regs);
|
||||
|
|
@ -457,13 +526,14 @@ void *__kprobes trampoline_handler(struct pt_regs *regs)
|
|||
}
|
||||
|
||||
kretprobe_assert(ri, orig_ret_address, trampoline_address);
|
||||
|
||||
spin_unlock_irqrestore(&kretprobe_lock, flags);
|
||||
|
||||
hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
|
||||
hlist_del(&ri->hlist);
|
||||
kfree(ri);
|
||||
}
|
||||
return (void*)orig_ret_address;
|
||||
return (void *)orig_ret_address;
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
@ -488,48 +558,55 @@ void *__kprobes trampoline_handler(struct pt_regs *regs)
|
|||
* that is atop the stack is the address following the copied instruction.
|
||||
* We need to make it the address following the original instruction.
|
||||
*
|
||||
* This function also checks instruction size for preparing direct execution.
|
||||
* If this is the first time we've single-stepped the instruction at
|
||||
* this probepoint, and the instruction is boostable, boost it: add a
|
||||
* jump instruction after the copied instruction, that jumps to the next
|
||||
* instruction after the probepoint.
|
||||
*/
|
||||
static void __kprobes resume_execution(struct kprobe *p,
|
||||
struct pt_regs *regs, struct kprobe_ctlblk *kcb)
|
||||
{
|
||||
unsigned long *tos = (unsigned long *)®s->sp;
|
||||
unsigned long copy_eip = (unsigned long)p->ainsn.insn;
|
||||
unsigned long orig_eip = (unsigned long)p->addr;
|
||||
unsigned long *tos = stack_addr(regs);
|
||||
unsigned long copy_ip = (unsigned long)p->ainsn.insn;
|
||||
unsigned long orig_ip = (unsigned long)p->addr;
|
||||
kprobe_opcode_t *insn = p->ainsn.insn;
|
||||
|
||||
regs->flags &= ~TF_MASK;
|
||||
switch (p->ainsn.insn[0]) {
|
||||
case 0x9c: /* pushfl */
|
||||
switch (*insn) {
|
||||
case 0x9c: /* pushfl */
|
||||
*tos &= ~(TF_MASK | IF_MASK);
|
||||
*tos |= kcb->kprobe_old_eflags;
|
||||
*tos |= kcb->kprobe_old_flags;
|
||||
break;
|
||||
case 0xc2: /* iret/ret/lret */
|
||||
case 0xc2: /* iret/ret/lret */
|
||||
case 0xc3:
|
||||
case 0xca:
|
||||
case 0xcb:
|
||||
case 0xcf:
|
||||
case 0xea: /* jmp absolute -- ip is correct */
|
||||
case 0xea: /* jmp absolute -- ip is correct */
|
||||
/* ip is already adjusted, no more changes required */
|
||||
p->ainsn.boostable = 1;
|
||||
goto no_change;
|
||||
case 0xe8: /* call relative - Fix return addr */
|
||||
*tos = orig_eip + (*tos - copy_eip);
|
||||
case 0xe8: /* call relative - Fix return addr */
|
||||
*tos = orig_ip + (*tos - copy_ip);
|
||||
break;
|
||||
case 0x9a: /* call absolute -- same as call absolute, indirect */
|
||||
*tos = orig_eip + (*tos - copy_eip);
|
||||
case 0x9a: /* call absolute -- same as call absolute, indirect */
|
||||
*tos = orig_ip + (*tos - copy_ip);
|
||||
goto no_change;
|
||||
case 0xff:
|
||||
if ((p->ainsn.insn[1] & 0x30) == 0x10) {
|
||||
if ((insn[1] & 0x30) == 0x10) {
|
||||
/*
|
||||
* call absolute, indirect
|
||||
* Fix return addr; ip is correct.
|
||||
* But this is not boostable
|
||||
*/
|
||||
*tos = orig_eip + (*tos - copy_eip);
|
||||
*tos = orig_ip + (*tos - copy_ip);
|
||||
goto no_change;
|
||||
} else if (((p->ainsn.insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */
|
||||
((p->ainsn.insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */
|
||||
/* ip is correct. And this is boostable */
|
||||
} else if (((insn[1] & 0x31) == 0x20) ||
|
||||
((insn[1] & 0x31) == 0x21)) {
|
||||
/*
|
||||
* jmp near and far, absolute indirect
|
||||
* ip is correct. And this is boostable
|
||||
*/
|
||||
p->ainsn.boostable = 1;
|
||||
goto no_change;
|
||||
}
|
||||
|
|
@ -538,21 +615,21 @@ static void __kprobes resume_execution(struct kprobe *p,
|
|||
}
|
||||
|
||||
if (p->ainsn.boostable == 0) {
|
||||
if ((regs->ip > copy_eip) &&
|
||||
(regs->ip - copy_eip) + 5 < MAX_INSN_SIZE) {
|
||||
if ((regs->ip > copy_ip) &&
|
||||
(regs->ip - copy_ip) + 5 < MAX_INSN_SIZE) {
|
||||
/*
|
||||
* These instructions can be executed directly if it
|
||||
* jumps back to correct address.
|
||||
*/
|
||||
set_jmp_op((void *)regs->ip,
|
||||
(void *)orig_eip + (regs->ip - copy_eip));
|
||||
(void *)orig_ip + (regs->ip - copy_ip));
|
||||
p->ainsn.boostable = 1;
|
||||
} else {
|
||||
p->ainsn.boostable = -1;
|
||||
}
|
||||
}
|
||||
|
||||
regs->ip = orig_eip + (regs->ip - copy_eip);
|
||||
regs->ip += orig_ip - copy_ip;
|
||||
|
||||
no_change:
|
||||
restore_btf();
|
||||
|
|
@ -578,10 +655,10 @@ static int __kprobes post_kprobe_handler(struct pt_regs *regs)
|
|||
}
|
||||
|
||||
resume_execution(cur, regs, kcb);
|
||||
regs->flags |= kcb->kprobe_saved_eflags;
|
||||
regs->flags |= kcb->kprobe_saved_flags;
|
||||
trace_hardirqs_fixup_flags(regs->flags);
|
||||
|
||||
/*Restore back the original saved kprobes variables and continue. */
|
||||
/* Restore back the original saved kprobes variables and continue. */
|
||||
if (kcb->kprobe_status == KPROBE_REENTER) {
|
||||
restore_previous_kprobe(kcb);
|
||||
goto out;
|
||||
|
|
@ -617,7 +694,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
|
|||
* normal page fault.
|
||||
*/
|
||||
regs->ip = (unsigned long)cur->addr;
|
||||
regs->flags |= kcb->kprobe_old_eflags;
|
||||
regs->flags |= kcb->kprobe_old_flags;
|
||||
if (kcb->kprobe_status == KPROBE_REENTER)
|
||||
restore_previous_kprobe(kcb);
|
||||
else
|
||||
|
|
@ -628,7 +705,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
|
|||
case KPROBE_HIT_SSDONE:
|
||||
/*
|
||||
* We increment the nmissed count for accounting,
|
||||
* we can also use npre/npostfault count for accouting
|
||||
* we can also use npre/npostfault count for accounting
|
||||
* these specific fault cases.
|
||||
*/
|
||||
kprobes_inc_nmissed_count(cur);
|
||||
|
|
@ -651,7 +728,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
|
|||
return 1;
|
||||
|
||||
/*
|
||||
* fixup_exception() could not handle it,
|
||||
* fixup routine could not handle it,
|
||||
* Let do_page_fault() fix it.
|
||||
*/
|
||||
break;
|
||||
|
|
@ -662,7 +739,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
|
|||
}
|
||||
|
||||
/*
|
||||
* Wrapper routine to for handling exceptions.
|
||||
* Wrapper routine for handling exceptions.
|
||||
*/
|
||||
int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
|
||||
unsigned long val, void *data)
|
||||
|
|
@ -703,11 +780,11 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
|
|||
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
||||
|
||||
kcb->jprobe_saved_regs = *regs;
|
||||
kcb->jprobe_saved_esp = ®s->sp;
|
||||
addr = (unsigned long)(kcb->jprobe_saved_esp);
|
||||
kcb->jprobe_saved_sp = stack_addr(regs);
|
||||
addr = (unsigned long)(kcb->jprobe_saved_sp);
|
||||
|
||||
/*
|
||||
* TBD: As Linus pointed out, gcc assumes that the callee
|
||||
* As Linus pointed out, gcc assumes that the callee
|
||||
* owns the argument space and could overwrite it, e.g.
|
||||
* tailcall optimization. So, to be absolutely safe
|
||||
* we also save and restore enough stack bytes to cover
|
||||
|
|
@ -730,21 +807,20 @@ void __kprobes jprobe_return(void)
|
|||
" .globl jprobe_return_end \n"
|
||||
" jprobe_return_end: \n"
|
||||
" nop \n"::"b"
|
||||
(kcb->jprobe_saved_esp):"memory");
|
||||
(kcb->jprobe_saved_sp):"memory");
|
||||
}
|
||||
|
||||
int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
|
||||
{
|
||||
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
||||
u8 *addr = (u8 *) (regs->ip - 1);
|
||||
unsigned long stack_addr = (unsigned long)(kcb->jprobe_saved_esp);
|
||||
struct jprobe *jp = container_of(p, struct jprobe, kp);
|
||||
|
||||
if ((addr > (u8 *) jprobe_return) && (addr < (u8 *) jprobe_return_end)) {
|
||||
if (®s->sp != kcb->jprobe_saved_esp) {
|
||||
if (stack_addr(regs) != kcb->jprobe_saved_sp) {
|
||||
struct pt_regs *saved_regs = &kcb->jprobe_saved_regs;
|
||||
printk("current sp %p does not match saved sp %p\n",
|
||||
®s->sp, kcb->jprobe_saved_esp);
|
||||
stack_addr(regs), kcb->jprobe_saved_sp);
|
||||
printk("Saved registers for jprobe %p\n", jp);
|
||||
show_registers(saved_regs);
|
||||
printk("Current registers\n");
|
||||
|
|
@ -752,20 +828,21 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
|
|||
BUG();
|
||||
}
|
||||
*regs = kcb->jprobe_saved_regs;
|
||||
memcpy((kprobe_opcode_t *) stack_addr, kcb->jprobes_stack,
|
||||
MIN_STACK_SIZE(stack_addr));
|
||||
memcpy((kprobe_opcode_t *)(kcb->jprobe_saved_sp),
|
||||
kcb->jprobes_stack,
|
||||
MIN_STACK_SIZE(kcb->jprobe_saved_sp));
|
||||
preempt_enable_no_resched();
|
||||
return 1;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
int __kprobes arch_trampoline_kprobe(struct kprobe *p)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
int __init arch_init_kprobes(void)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
int __kprobes arch_trampoline_kprobe(struct kprobe *p)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -40,16 +40,97 @@
|
|||
#include <linux/module.h>
|
||||
#include <linux/kdebug.h>
|
||||
|
||||
#include <asm/cacheflush.h>
|
||||
#include <asm/desc.h>
|
||||
#include <asm/pgtable.h>
|
||||
#include <asm/uaccess.h>
|
||||
#include <asm/alternative.h>
|
||||
|
||||
void jprobe_return_end(void);
|
||||
static void __kprobes arch_copy_kprobe(struct kprobe *p);
|
||||
|
||||
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
|
||||
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
|
||||
|
||||
#define stack_addr(regs) ((unsigned long *)regs->sp)
|
||||
|
||||
#define W(row, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf)\
|
||||
(((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \
|
||||
(b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) | \
|
||||
(b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) | \
|
||||
(bc##UL << 0xc)|(bd##UL << 0xd)|(be##UL << 0xe)|(bf##UL << 0xf)) \
|
||||
<< (row % 32))
|
||||
/*
|
||||
* Undefined/reserved opcodes, conditional jump, Opcode Extension
|
||||
* Groups, and some special opcodes can not boost.
|
||||
*/
|
||||
static const u32 twobyte_is_boostable[256 / 32] = {
|
||||
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
|
||||
/* ---------------------------------------------- */
|
||||
W(0x00, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0) | /* 00 */
|
||||
W(0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 10 */
|
||||
W(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 20 */
|
||||
W(0x30, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 30 */
|
||||
W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 40 */
|
||||
W(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 50 */
|
||||
W(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1) | /* 60 */
|
||||
W(0x70, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) , /* 70 */
|
||||
W(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 80 */
|
||||
W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 90 */
|
||||
W(0xa0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) | /* a0 */
|
||||
W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) , /* b0 */
|
||||
W(0xc0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) | /* c0 */
|
||||
W(0xd0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) , /* d0 */
|
||||
W(0xe0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) | /* e0 */
|
||||
W(0xf0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0) /* f0 */
|
||||
/* ----------------------------------------------- */
|
||||
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
|
||||
};
|
||||
static const u32 onebyte_has_modrm[256 / 32] = {
|
||||
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
|
||||
/* ----------------------------------------------- */
|
||||
W(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* 00 */
|
||||
W(0x10, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) , /* 10 */
|
||||
W(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) | /* 20 */
|
||||
W(0x30, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) , /* 30 */
|
||||
W(0x40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 40 */
|
||||
W(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 50 */
|
||||
W(0x60, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0) | /* 60 */
|
||||
W(0x70, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 70 */
|
||||
W(0x80, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 80 */
|
||||
W(0x90, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 90 */
|
||||
W(0xa0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* a0 */
|
||||
W(0xb0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* b0 */
|
||||
W(0xc0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) | /* c0 */
|
||||
W(0xd0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) , /* d0 */
|
||||
W(0xe0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* e0 */
|
||||
W(0xf0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) /* f0 */
|
||||
/* ----------------------------------------------- */
|
||||
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
|
||||
};
|
||||
static const u32 twobyte_has_modrm[256 / 32] = {
|
||||
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
|
||||
/* ----------------------------------------------- */
|
||||
W(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1) | /* 0f */
|
||||
W(0x10, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0) , /* 1f */
|
||||
W(0x20, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1) | /* 2f */
|
||||
W(0x30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) , /* 3f */
|
||||
W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 4f */
|
||||
W(0x50, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 5f */
|
||||
W(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* 6f */
|
||||
W(0x70, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1) , /* 7f */
|
||||
W(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) | /* 8f */
|
||||
W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* 9f */
|
||||
W(0xa0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) | /* af */
|
||||
W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1) , /* bf */
|
||||
W(0xc0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) | /* cf */
|
||||
W(0xd0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) , /* df */
|
||||
W(0xe0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) | /* ef */
|
||||
W(0xf0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0) /* ff */
|
||||
/* ----------------------------------------------- */
|
||||
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
|
||||
};
|
||||
#undef W
|
||||
|
||||
struct kretprobe_blackpoint kretprobe_blacklist[] = {
|
||||
{"__switch_to", }, /* This function switches only current task, but
|
||||
doesn't switch kernel stack.*/
|
||||
|
|
@ -70,44 +151,11 @@ static __always_inline void set_jmp_op(void *from, void *to)
|
|||
}
|
||||
|
||||
/*
|
||||
* returns non-zero if opcode is boostable
|
||||
* returns non-zero if opcode is boostable.
|
||||
* RIP relative instructions are adjusted at copying time
|
||||
*/
|
||||
static __always_inline int can_boost(kprobe_opcode_t *opcodes)
|
||||
{
|
||||
#define W(row, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf)\
|
||||
(((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \
|
||||
(b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) | \
|
||||
(b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) | \
|
||||
(bc##UL << 0xc)|(bd##UL << 0xd)|(be##UL << 0xe)|(bf##UL << 0xf)) \
|
||||
<< (row % 64))
|
||||
/*
|
||||
* Undefined/reserved opcodes, conditional jump, Opcode Extension
|
||||
* Groups, and some special opcodes can not boost.
|
||||
*/
|
||||
static const unsigned long twobyte_is_boostable[256 / 64] = {
|
||||
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
|
||||
/* ---------------------------------------------- */
|
||||
W(0x00, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0)|/* 00 */
|
||||
W(0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)|/* 10 */
|
||||
W(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)|/* 20 */
|
||||
W(0x30, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0),/* 30 */
|
||||
W(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1)|/* 40 */
|
||||
W(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)|/* 50 */
|
||||
W(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1)|/* 60 */
|
||||
W(0x70, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1),/* 70 */
|
||||
W(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)|/* 80 */
|
||||
W(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1)|/* 90 */
|
||||
W(0xa0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1)|/* a0 */
|
||||
W(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1),/* b0 */
|
||||
W(0xc0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1)|/* c0 */
|
||||
W(0xd0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1)|/* d0 */
|
||||
W(0xe0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1)|/* e0 */
|
||||
W(0xf0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0) /* f0 */
|
||||
/* ----------------------------------------------- */
|
||||
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
|
||||
};
|
||||
#undef W
|
||||
kprobe_opcode_t opcode;
|
||||
kprobe_opcode_t *orig_opcodes = opcodes;
|
||||
|
||||
|
|
@ -120,7 +168,8 @@ static __always_inline int can_boost(kprobe_opcode_t *opcodes)
|
|||
if (opcode == 0x0f) {
|
||||
if (opcodes - orig_opcodes > MAX_INSN_SIZE - 1)
|
||||
return 0;
|
||||
return test_bit(*opcodes, twobyte_is_boostable);
|
||||
return test_bit(*opcodes,
|
||||
(unsigned long *)twobyte_is_boostable);
|
||||
}
|
||||
|
||||
switch (opcode & 0xf0) {
|
||||
|
|
@ -169,80 +218,25 @@ static int __kprobes is_IF_modifier(kprobe_opcode_t *insn)
|
|||
return 1;
|
||||
}
|
||||
|
||||
if (*insn >= 0x40 && *insn <= 0x4f && *++insn == 0xcf)
|
||||
return 1;
|
||||
return 0;
|
||||
}
|
||||
|
||||
int __kprobes arch_prepare_kprobe(struct kprobe *p)
|
||||
{
|
||||
/* insn: must be on special executable page on x86_64. */
|
||||
p->ainsn.insn = get_insn_slot();
|
||||
if (!p->ainsn.insn) {
|
||||
return -ENOMEM;
|
||||
}
|
||||
arch_copy_kprobe(p);
|
||||
/*
|
||||
* on 64 bit x86, 0x40-0x4f are prefixes so we need to look
|
||||
* at the next byte instead.. but of course not recurse infinitely
|
||||
*/
|
||||
if (*insn >= 0x40 && *insn <= 0x4f)
|
||||
return is_IF_modifier(++insn);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* Determine if the instruction uses the %rip-relative addressing mode.
|
||||
* Adjust the displacement if the instruction uses the %rip-relative
|
||||
* addressing mode.
|
||||
* If it does, Return the address of the 32-bit displacement word.
|
||||
* If not, return null.
|
||||
*/
|
||||
static s32 __kprobes *is_riprel(u8 *insn)
|
||||
static void __kprobes fix_riprel(struct kprobe *p)
|
||||
{
|
||||
#define W(row,b0,b1,b2,b3,b4,b5,b6,b7,b8,b9,ba,bb,bc,bd,be,bf) \
|
||||
(((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \
|
||||
(b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) | \
|
||||
(b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) | \
|
||||
(bc##UL << 0xc)|(bd##UL << 0xd)|(be##UL << 0xe)|(bf##UL << 0xf)) \
|
||||
<< (row % 64))
|
||||
static const u64 onebyte_has_modrm[256 / 64] = {
|
||||
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
|
||||
/* ------------------------------- */
|
||||
W(0x00, 1,1,1,1,0,0,0,0,1,1,1,1,0,0,0,0)| /* 00 */
|
||||
W(0x10, 1,1,1,1,0,0,0,0,1,1,1,1,0,0,0,0)| /* 10 */
|
||||
W(0x20, 1,1,1,1,0,0,0,0,1,1,1,1,0,0,0,0)| /* 20 */
|
||||
W(0x30, 1,1,1,1,0,0,0,0,1,1,1,1,0,0,0,0), /* 30 */
|
||||
W(0x40, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)| /* 40 */
|
||||
W(0x50, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)| /* 50 */
|
||||
W(0x60, 0,0,1,1,0,0,0,0,0,1,0,1,0,0,0,0)| /* 60 */
|
||||
W(0x70, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0), /* 70 */
|
||||
W(0x80, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* 80 */
|
||||
W(0x90, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)| /* 90 */
|
||||
W(0xa0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)| /* a0 */
|
||||
W(0xb0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0), /* b0 */
|
||||
W(0xc0, 1,1,0,0,1,1,1,1,0,0,0,0,0,0,0,0)| /* c0 */
|
||||
W(0xd0, 1,1,1,1,0,0,0,0,1,1,1,1,1,1,1,1)| /* d0 */
|
||||
W(0xe0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)| /* e0 */
|
||||
W(0xf0, 0,0,0,0,0,0,1,1,0,0,0,0,0,0,1,1) /* f0 */
|
||||
/* ------------------------------- */
|
||||
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
|
||||
};
|
||||
static const u64 twobyte_has_modrm[256 / 64] = {
|
||||
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
|
||||
/* ------------------------------- */
|
||||
W(0x00, 1,1,1,1,0,0,0,0,0,0,0,0,0,1,0,1)| /* 0f */
|
||||
W(0x10, 1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0)| /* 1f */
|
||||
W(0x20, 1,1,1,1,1,0,1,0,1,1,1,1,1,1,1,1)| /* 2f */
|
||||
W(0x30, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0), /* 3f */
|
||||
W(0x40, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* 4f */
|
||||
W(0x50, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* 5f */
|
||||
W(0x60, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* 6f */
|
||||
W(0x70, 1,1,1,1,1,1,1,0,0,0,0,0,1,1,1,1), /* 7f */
|
||||
W(0x80, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)| /* 8f */
|
||||
W(0x90, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* 9f */
|
||||
W(0xa0, 0,0,0,1,1,1,1,1,0,0,0,1,1,1,1,1)| /* af */
|
||||
W(0xb0, 1,1,1,1,1,1,1,1,0,0,1,1,1,1,1,1), /* bf */
|
||||
W(0xc0, 1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0)| /* cf */
|
||||
W(0xd0, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* df */
|
||||
W(0xe0, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1)| /* ef */
|
||||
W(0xf0, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0) /* ff */
|
||||
/* ------------------------------- */
|
||||
/* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
|
||||
};
|
||||
#undef W
|
||||
u8 *insn = p->ainsn.insn;
|
||||
s64 disp;
|
||||
int need_modrm;
|
||||
|
||||
/* Skip legacy instruction prefixes. */
|
||||
|
|
@ -271,54 +265,60 @@ static s32 __kprobes *is_riprel(u8 *insn)
|
|||
|
||||
if (*insn == 0x0f) { /* Two-byte opcode. */
|
||||
++insn;
|
||||
need_modrm = test_bit(*insn, twobyte_has_modrm);
|
||||
} else { /* One-byte opcode. */
|
||||
need_modrm = test_bit(*insn, onebyte_has_modrm);
|
||||
}
|
||||
need_modrm = test_bit(*insn,
|
||||
(unsigned long *)twobyte_has_modrm);
|
||||
} else /* One-byte opcode. */
|
||||
need_modrm = test_bit(*insn,
|
||||
(unsigned long *)onebyte_has_modrm);
|
||||
|
||||
if (need_modrm) {
|
||||
u8 modrm = *++insn;
|
||||
if ((modrm & 0xc7) == 0x05) { /* %rip+disp32 addressing mode */
|
||||
/* Displacement follows ModRM byte. */
|
||||
return (s32 *) ++insn;
|
||||
++insn;
|
||||
/*
|
||||
* The copied instruction uses the %rip-relative
|
||||
* addressing mode. Adjust the displacement for the
|
||||
* difference between the original location of this
|
||||
* instruction and the location of the copy that will
|
||||
* actually be run. The tricky bit here is making sure
|
||||
* that the sign extension happens correctly in this
|
||||
* calculation, since we need a signed 32-bit result to
|
||||
* be sign-extended to 64 bits when it's added to the
|
||||
* %rip value and yield the same 64-bit result that the
|
||||
* sign-extension of the original signed 32-bit
|
||||
* displacement would have given.
|
||||
*/
|
||||
disp = (u8 *) p->addr + *((s32 *) insn) -
|
||||
(u8 *) p->ainsn.insn;
|
||||
BUG_ON((s64) (s32) disp != disp); /* Sanity check. */
|
||||
*(s32 *)insn = (s32) disp;
|
||||
}
|
||||
}
|
||||
|
||||
/* No %rip-relative addressing mode here. */
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static void __kprobes arch_copy_kprobe(struct kprobe *p)
|
||||
{
|
||||
s32 *ripdisp;
|
||||
memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE);
|
||||
ripdisp = is_riprel(p->ainsn.insn);
|
||||
if (ripdisp) {
|
||||
/*
|
||||
* The copied instruction uses the %rip-relative
|
||||
* addressing mode. Adjust the displacement for the
|
||||
* difference between the original location of this
|
||||
* instruction and the location of the copy that will
|
||||
* actually be run. The tricky bit here is making sure
|
||||
* that the sign extension happens correctly in this
|
||||
* calculation, since we need a signed 32-bit result to
|
||||
* be sign-extended to 64 bits when it's added to the
|
||||
* %rip value and yield the same 64-bit result that the
|
||||
* sign-extension of the original signed 32-bit
|
||||
* displacement would have given.
|
||||
*/
|
||||
s64 disp = (u8 *) p->addr + *ripdisp - (u8 *) p->ainsn.insn;
|
||||
BUG_ON((s64) (s32) disp != disp); /* Sanity check. */
|
||||
*ripdisp = disp;
|
||||
}
|
||||
if (can_boost(p->addr)) {
|
||||
memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
|
||||
fix_riprel(p);
|
||||
if (can_boost(p->addr))
|
||||
p->ainsn.boostable = 0;
|
||||
} else {
|
||||
else
|
||||
p->ainsn.boostable = -1;
|
||||
}
|
||||
|
||||
p->opcode = *p->addr;
|
||||
}
|
||||
|
||||
int __kprobes arch_prepare_kprobe(struct kprobe *p)
|
||||
{
|
||||
/* insn: must be on special executable page on x86. */
|
||||
p->ainsn.insn = get_insn_slot();
|
||||
if (!p->ainsn.insn)
|
||||
return -ENOMEM;
|
||||
arch_copy_kprobe(p);
|
||||
return 0;
|
||||
}
|
||||
|
||||
void __kprobes arch_arm_kprobe(struct kprobe *p)
|
||||
{
|
||||
text_poke(p->addr, ((unsigned char []){BREAKPOINT_INSTRUCTION}), 1);
|
||||
|
|
@ -340,26 +340,26 @@ static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
|
|||
{
|
||||
kcb->prev_kprobe.kp = kprobe_running();
|
||||
kcb->prev_kprobe.status = kcb->kprobe_status;
|
||||
kcb->prev_kprobe.old_rflags = kcb->kprobe_old_rflags;
|
||||
kcb->prev_kprobe.saved_rflags = kcb->kprobe_saved_rflags;
|
||||
kcb->prev_kprobe.old_flags = kcb->kprobe_old_flags;
|
||||
kcb->prev_kprobe.saved_flags = kcb->kprobe_saved_flags;
|
||||
}
|
||||
|
||||
static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
|
||||
{
|
||||
__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
|
||||
kcb->kprobe_status = kcb->prev_kprobe.status;
|
||||
kcb->kprobe_old_rflags = kcb->prev_kprobe.old_rflags;
|
||||
kcb->kprobe_saved_rflags = kcb->prev_kprobe.saved_rflags;
|
||||
kcb->kprobe_old_flags = kcb->prev_kprobe.old_flags;
|
||||
kcb->kprobe_saved_flags = kcb->prev_kprobe.saved_flags;
|
||||
}
|
||||
|
||||
static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
|
||||
struct kprobe_ctlblk *kcb)
|
||||
{
|
||||
__get_cpu_var(current_kprobe) = p;
|
||||
kcb->kprobe_saved_rflags = kcb->kprobe_old_rflags
|
||||
kcb->kprobe_saved_flags = kcb->kprobe_old_flags
|
||||
= (regs->flags & (TF_MASK | IF_MASK));
|
||||
if (is_IF_modifier(p->ainsn.insn))
|
||||
kcb->kprobe_saved_rflags &= ~IF_MASK;
|
||||
kcb->kprobe_saved_flags &= ~IF_MASK;
|
||||
}
|
||||
|
||||
static __always_inline void clear_btf(void)
|
||||
|
|
@ -390,20 +390,27 @@ static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
|
|||
void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
|
||||
struct pt_regs *regs)
|
||||
{
|
||||
unsigned long *sara = (unsigned long *)regs->sp;
|
||||
unsigned long *sara = stack_addr(regs);
|
||||
|
||||
ri->ret_addr = (kprobe_opcode_t *) *sara;
|
||||
|
||||
/* Replace the return addr with trampoline addr */
|
||||
*sara = (unsigned long) &kretprobe_trampoline;
|
||||
}
|
||||
|
||||
int __kprobes kprobe_handler(struct pt_regs *regs)
|
||||
/*
|
||||
* Interrupts are disabled on entry as trap3 is an interrupt gate and they
|
||||
* remain disabled thorough out this function.
|
||||
*/
|
||||
static int __kprobes kprobe_handler(struct pt_regs *regs)
|
||||
{
|
||||
struct kprobe *p;
|
||||
int ret = 0;
|
||||
kprobe_opcode_t *addr = (kprobe_opcode_t *)(regs->ip - sizeof(kprobe_opcode_t));
|
||||
kprobe_opcode_t *addr;
|
||||
struct kprobe_ctlblk *kcb;
|
||||
|
||||
addr = (kprobe_opcode_t *)(regs->ip - sizeof(kprobe_opcode_t));
|
||||
|
||||
/*
|
||||
* We don't want to be preempted for the entire
|
||||
* duration of kprobe processing
|
||||
|
|
@ -418,7 +425,7 @@ int __kprobes kprobe_handler(struct pt_regs *regs)
|
|||
if (kcb->kprobe_status == KPROBE_HIT_SS &&
|
||||
*p->ainsn.insn == BREAKPOINT_INSTRUCTION) {
|
||||
regs->flags &= ~TF_MASK;
|
||||
regs->flags |= kcb->kprobe_saved_rflags;
|
||||
regs->flags |= kcb->kprobe_saved_flags;
|
||||
goto no_kprobe;
|
||||
} else if (kcb->kprobe_status == KPROBE_HIT_SSDONE) {
|
||||
/* TODO: Provide re-entrancy from
|
||||
|
|
@ -429,22 +436,20 @@ int __kprobes kprobe_handler(struct pt_regs *regs)
|
|||
arch_disarm_kprobe(p);
|
||||
regs->ip = (unsigned long)p->addr;
|
||||
reset_current_kprobe();
|
||||
ret = 1;
|
||||
} else {
|
||||
/* We have reentered the kprobe_handler(), since
|
||||
* another probe was hit while within the
|
||||
* handler. We here save the original kprobe
|
||||
* variables and just single step on instruction
|
||||
* of the new probe without calling any user
|
||||
* handlers.
|
||||
*/
|
||||
save_previous_kprobe(kcb);
|
||||
set_current_kprobe(p, regs, kcb);
|
||||
kprobes_inc_nmissed_count(p);
|
||||
prepare_singlestep(p, regs);
|
||||
kcb->kprobe_status = KPROBE_REENTER;
|
||||
return 1;
|
||||
}
|
||||
/* We have reentered the kprobe_handler(), since
|
||||
* another probe was hit while within the handler.
|
||||
* We here save the original kprobes variables and
|
||||
* just single step on the instruction of the new probe
|
||||
* without calling any user handlers.
|
||||
*/
|
||||
save_previous_kprobe(kcb);
|
||||
set_current_kprobe(p, regs, kcb);
|
||||
kprobes_inc_nmissed_count(p);
|
||||
prepare_singlestep(p, regs);
|
||||
kcb->kprobe_status = KPROBE_REENTER;
|
||||
return 1;
|
||||
} else {
|
||||
if (*addr != BREAKPOINT_INSTRUCTION) {
|
||||
/* The breakpoint instruction was removed by
|
||||
|
|
@ -578,23 +583,23 @@ fastcall void * __kprobes trampoline_handler(struct pt_regs *regs)
|
|||
INIT_HLIST_HEAD(&empty_rp);
|
||||
spin_lock_irqsave(&kretprobe_lock, flags);
|
||||
head = kretprobe_inst_table_head(current);
|
||||
/* fixup rt_regs */
|
||||
/* fixup registers */
|
||||
regs->cs = __KERNEL_CS;
|
||||
regs->ip = trampoline_address;
|
||||
regs->orig_ax = 0xffffffffffffffff;
|
||||
regs->orig_ax = ~0UL;
|
||||
|
||||
/*
|
||||
* It is possible to have multiple instances associated with a given
|
||||
* task either because an multiple functions in the call path
|
||||
* have a return probe installed on them, and/or more then one return
|
||||
* task either because multiple functions in the call path have
|
||||
* return probes installed on them, and/or more then one
|
||||
* return probe was registered for a target function.
|
||||
*
|
||||
* We can handle this because:
|
||||
* - instances are always inserted at the head of the list
|
||||
* - instances are always pushed into the head of the list
|
||||
* - when multiple return probes are registered for the same
|
||||
* function, the first instance's ret_addr will point to the
|
||||
* real return address, and all the rest will point to
|
||||
* kretprobe_trampoline
|
||||
* function, the (chronologically) first instance's ret_addr
|
||||
* will be the real return address, and all the rest will
|
||||
* point to kretprobe_trampoline.
|
||||
*/
|
||||
hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
|
||||
if (ri->task != current)
|
||||
|
|
@ -661,9 +666,9 @@ fastcall void * __kprobes trampoline_handler(struct pt_regs *regs)
|
|||
static void __kprobes resume_execution(struct kprobe *p,
|
||||
struct pt_regs *regs, struct kprobe_ctlblk *kcb)
|
||||
{
|
||||
unsigned long *tos = (unsigned long *)regs->sp;
|
||||
unsigned long copy_rip = (unsigned long)p->ainsn.insn;
|
||||
unsigned long orig_rip = (unsigned long)p->addr;
|
||||
unsigned long *tos = stack_addr(regs);
|
||||
unsigned long copy_ip = (unsigned long)p->ainsn.insn;
|
||||
unsigned long orig_ip = (unsigned long)p->addr;
|
||||
kprobe_opcode_t *insn = p->ainsn.insn;
|
||||
|
||||
/*skip the REX prefix*/
|
||||
|
|
@ -674,7 +679,7 @@ static void __kprobes resume_execution(struct kprobe *p,
|
|||
switch (*insn) {
|
||||
case 0x9c: /* pushfl */
|
||||
*tos &= ~(TF_MASK | IF_MASK);
|
||||
*tos |= kcb->kprobe_old_rflags;
|
||||
*tos |= kcb->kprobe_old_flags;
|
||||
break;
|
||||
case 0xc2: /* iret/ret/lret */
|
||||
case 0xc3:
|
||||
|
|
@ -686,18 +691,23 @@ static void __kprobes resume_execution(struct kprobe *p,
|
|||
p->ainsn.boostable = 1;
|
||||
goto no_change;
|
||||
case 0xe8: /* call relative - Fix return addr */
|
||||
*tos = orig_rip + (*tos - copy_rip);
|
||||
*tos = orig_ip + (*tos - copy_ip);
|
||||
break;
|
||||
case 0xff:
|
||||
if ((insn[1] & 0x30) == 0x10) {
|
||||
/* call absolute, indirect */
|
||||
/* Fix return addr; ip is correct. */
|
||||
/* not boostable */
|
||||
*tos = orig_rip + (*tos - copy_rip);
|
||||
/*
|
||||
* call absolute, indirect
|
||||
* Fix return addr; ip is correct.
|
||||
* But this is not boostable
|
||||
*/
|
||||
*tos = orig_ip + (*tos - copy_ip);
|
||||
goto no_change;
|
||||
} else if (((insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */
|
||||
((insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */
|
||||
/* ip is correct. And this is boostable */
|
||||
} else if (((insn[1] & 0x31) == 0x20) ||
|
||||
((insn[1] & 0x31) == 0x21)) {
|
||||
/*
|
||||
* jmp near and far, absolute indirect
|
||||
* ip is correct. And this is boostable
|
||||
*/
|
||||
p->ainsn.boostable = 1;
|
||||
goto no_change;
|
||||
}
|
||||
|
|
@ -706,21 +716,21 @@ static void __kprobes resume_execution(struct kprobe *p,
|
|||
}
|
||||
|
||||
if (p->ainsn.boostable == 0) {
|
||||
if ((regs->ip > copy_rip) &&
|
||||
(regs->ip - copy_rip) + 5 < MAX_INSN_SIZE) {
|
||||
if ((regs->ip > copy_ip) &&
|
||||
(regs->ip - copy_ip) + 5 < MAX_INSN_SIZE) {
|
||||
/*
|
||||
* These instructions can be executed directly if it
|
||||
* jumps back to correct address.
|
||||
*/
|
||||
set_jmp_op((void *)regs->ip,
|
||||
(void *)orig_rip + (regs->ip - copy_rip));
|
||||
(void *)orig_ip + (regs->ip - copy_ip));
|
||||
p->ainsn.boostable = 1;
|
||||
} else {
|
||||
p->ainsn.boostable = -1;
|
||||
}
|
||||
}
|
||||
|
||||
regs->ip = orig_rip + (regs->ip - copy_rip);
|
||||
regs->ip += orig_ip - copy_ip;
|
||||
|
||||
no_change:
|
||||
restore_btf();
|
||||
|
|
@ -728,7 +738,11 @@ static void __kprobes resume_execution(struct kprobe *p,
|
|||
return;
|
||||
}
|
||||
|
||||
int __kprobes post_kprobe_handler(struct pt_regs *regs)
|
||||
/*
|
||||
* Interrupts are disabled on entry as trap1 is an interrupt gate and they
|
||||
* remain disabled thoroughout this function.
|
||||
*/
|
||||
static int __kprobes post_kprobe_handler(struct pt_regs *regs)
|
||||
{
|
||||
struct kprobe *cur = kprobe_running();
|
||||
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
||||
|
|
@ -742,10 +756,10 @@ int __kprobes post_kprobe_handler(struct pt_regs *regs)
|
|||
}
|
||||
|
||||
resume_execution(cur, regs, kcb);
|
||||
regs->flags |= kcb->kprobe_saved_rflags;
|
||||
regs->flags |= kcb->kprobe_saved_flags;
|
||||
trace_hardirqs_fixup_flags(regs->flags);
|
||||
|
||||
/* Restore the original saved kprobes variables and continue. */
|
||||
/* Restore back the original saved kprobes variables and continue. */
|
||||
if (kcb->kprobe_status == KPROBE_REENTER) {
|
||||
restore_previous_kprobe(kcb);
|
||||
goto out;
|
||||
|
|
@ -782,7 +796,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
|
|||
* normal page fault.
|
||||
*/
|
||||
regs->ip = (unsigned long)cur->addr;
|
||||
regs->flags |= kcb->kprobe_old_rflags;
|
||||
regs->flags |= kcb->kprobe_old_flags;
|
||||
if (kcb->kprobe_status == KPROBE_REENTER)
|
||||
restore_previous_kprobe(kcb);
|
||||
else
|
||||
|
|
@ -793,7 +807,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
|
|||
case KPROBE_HIT_SSDONE:
|
||||
/*
|
||||
* We increment the nmissed count for accounting,
|
||||
* we can also use npre/npostfault count for accouting
|
||||
* we can also use npre/npostfault count for accounting
|
||||
* these specific fault cases.
|
||||
*/
|
||||
kprobes_inc_nmissed_count(cur);
|
||||
|
|
@ -819,7 +833,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
|
|||
}
|
||||
|
||||
/*
|
||||
* fixup() could not handle it,
|
||||
* fixup routine could not handle it,
|
||||
* Let do_page_fault() fix it.
|
||||
*/
|
||||
break;
|
||||
|
|
@ -838,7 +852,7 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
|
|||
struct die_args *args = (struct die_args *)data;
|
||||
int ret = NOTIFY_DONE;
|
||||
|
||||
if (args->regs && user_mode(args->regs))
|
||||
if (args->regs && user_mode_vm(args->regs))
|
||||
return ret;
|
||||
|
||||
switch (val) {
|
||||
|
|
@ -871,8 +885,9 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
|
|||
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
||||
|
||||
kcb->jprobe_saved_regs = *regs;
|
||||
kcb->jprobe_saved_rsp = (long *) regs->sp;
|
||||
addr = (unsigned long)(kcb->jprobe_saved_rsp);
|
||||
kcb->jprobe_saved_sp = stack_addr(regs);
|
||||
addr = (unsigned long)(kcb->jprobe_saved_sp);
|
||||
|
||||
/*
|
||||
* As Linus pointed out, gcc assumes that the callee
|
||||
* owns the argument space and could overwrite it, e.g.
|
||||
|
|
@ -897,21 +912,20 @@ void __kprobes jprobe_return(void)
|
|||
" .globl jprobe_return_end \n"
|
||||
" jprobe_return_end: \n"
|
||||
" nop \n"::"b"
|
||||
(kcb->jprobe_saved_rsp):"memory");
|
||||
(kcb->jprobe_saved_sp):"memory");
|
||||
}
|
||||
|
||||
int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
|
||||
{
|
||||
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
||||
u8 *addr = (u8 *) (regs->ip - 1);
|
||||
unsigned long stack_addr = (unsigned long)(kcb->jprobe_saved_rsp);
|
||||
struct jprobe *jp = container_of(p, struct jprobe, kp);
|
||||
|
||||
if ((addr > (u8 *) jprobe_return) && (addr < (u8 *) jprobe_return_end)) {
|
||||
if ((unsigned long *)regs->sp != kcb->jprobe_saved_rsp) {
|
||||
if (stack_addr(regs) != kcb->jprobe_saved_sp) {
|
||||
struct pt_regs *saved_regs = &kcb->jprobe_saved_regs;
|
||||
printk("current sp %p does not match saved sp %p\n",
|
||||
(long *)regs->sp, kcb->jprobe_saved_rsp);
|
||||
stack_addr(regs), kcb->jprobe_saved_sp);
|
||||
printk("Saved registers for jprobe %p\n", jp);
|
||||
show_registers(saved_regs);
|
||||
printk("Current registers\n");
|
||||
|
|
@ -919,8 +933,9 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
|
|||
BUG();
|
||||
}
|
||||
*regs = kcb->jprobe_saved_regs;
|
||||
memcpy((kprobe_opcode_t *) stack_addr, kcb->jprobes_stack,
|
||||
MIN_STACK_SIZE(stack_addr));
|
||||
memcpy((kprobe_opcode_t *)(kcb->jprobe_saved_sp),
|
||||
kcb->jprobes_stack,
|
||||
MIN_STACK_SIZE(kcb->jprobe_saved_sp));
|
||||
preempt_enable_no_resched();
|
||||
return 1;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -25,7 +25,6 @@
|
|||
#include <linux/kprobes.h>
|
||||
#include <linux/uaccess.h>
|
||||
#include <linux/kdebug.h>
|
||||
#include <linux/kprobes.h>
|
||||
|
||||
#include <asm/system.h>
|
||||
#include <asm/desc.h>
|
||||
|
|
|
|||
|
|
@ -25,7 +25,6 @@
|
|||
#include <linux/kprobes.h>
|
||||
#include <linux/uaccess.h>
|
||||
#include <linux/kdebug.h>
|
||||
#include <linux/kprobes.h>
|
||||
|
||||
#include <asm/system.h>
|
||||
#include <asm/pgalloc.h>
|
||||
|
|
|
|||
|
|
@ -2,7 +2,6 @@
|
|||
#define _ASM_KPROBES_H
|
||||
/*
|
||||
* Kernel Probes (KProbes)
|
||||
* include/asm-i386/kprobes.h
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License as published by
|
||||
|
|
@ -23,14 +22,17 @@
|
|||
* 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
|
||||
* Probes initial implementation ( includes suggestions from
|
||||
* Rusty Russell).
|
||||
* 2004-Oct Prasanna S Panchamukhi <prasanna@in.ibm.com> and Jim Keniston
|
||||
* kenistoj@us.ibm.com adopted from i386.
|
||||
*/
|
||||
#include <linux/types.h>
|
||||
#include <linux/ptrace.h>
|
||||
#include <linux/percpu.h>
|
||||
|
||||
#define __ARCH_WANT_KPROBES_INSN_SLOT
|
||||
|
||||
struct kprobe;
|
||||
struct pt_regs;
|
||||
struct kprobe;
|
||||
|
||||
typedef u8 kprobe_opcode_t;
|
||||
#define BREAKPOINT_INSTRUCTION 0xcc
|
||||
|
|
@ -38,9 +40,11 @@ typedef u8 kprobe_opcode_t;
|
|||
#define MAX_INSN_SIZE 16
|
||||
#define MAX_STACK_SIZE 64
|
||||
#define MIN_STACK_SIZE(ADDR) (((MAX_STACK_SIZE) < \
|
||||
(((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR))) \
|
||||
(((unsigned long)current_thread_info()) + THREAD_SIZE \
|
||||
- (unsigned long)(ADDR))) \
|
||||
? (MAX_STACK_SIZE) \
|
||||
: (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))
|
||||
: (((unsigned long)current_thread_info()) + THREAD_SIZE \
|
||||
- (unsigned long)(ADDR)))
|
||||
|
||||
#define ARCH_SUPPORTS_KRETPROBES
|
||||
#define flush_insn_slot(p) do { } while (0)
|
||||
|
|
@ -55,8 +59,12 @@ struct arch_specific_insn {
|
|||
/* copy of the original instruction */
|
||||
kprobe_opcode_t *insn;
|
||||
/*
|
||||
* If this flag is not 0, this kprobe can be boost when its
|
||||
* post_handler and break_handler is not set.
|
||||
* boostable = -1: This instruction type is not boostable.
|
||||
* boostable = 0: This instruction type is boostable.
|
||||
* boostable = 1: This instruction has been boosted: we have
|
||||
* added a relative jump after the instruction copy in insn,
|
||||
* so no single-step and fixup are needed (unless there's
|
||||
* a post_handler or break_handler).
|
||||
*/
|
||||
int boostable;
|
||||
};
|
||||
|
|
@ -64,16 +72,16 @@ struct arch_specific_insn {
|
|||
struct prev_kprobe {
|
||||
struct kprobe *kp;
|
||||
unsigned long status;
|
||||
unsigned long old_eflags;
|
||||
unsigned long saved_eflags;
|
||||
unsigned long old_flags;
|
||||
unsigned long saved_flags;
|
||||
};
|
||||
|
||||
/* per-cpu kprobe control block */
|
||||
struct kprobe_ctlblk {
|
||||
unsigned long kprobe_status;
|
||||
unsigned long kprobe_old_eflags;
|
||||
unsigned long kprobe_saved_eflags;
|
||||
unsigned long *jprobe_saved_esp;
|
||||
unsigned long kprobe_old_flags;
|
||||
unsigned long kprobe_saved_flags;
|
||||
unsigned long *jprobe_saved_sp;
|
||||
struct pt_regs jprobe_saved_regs;
|
||||
kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
|
||||
struct prev_kprobe prev_kprobe;
|
||||
|
|
@ -88,7 +96,7 @@ static inline void restore_interrupts(struct pt_regs *regs)
|
|||
local_irq_enable();
|
||||
}
|
||||
|
||||
extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
|
||||
extern int kprobe_exceptions_notify(struct notifier_block *self,
|
||||
unsigned long val, void *data);
|
||||
extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
|
||||
#endif /* _ASM_KPROBES_H */
|
||||
|
|
|
|||
|
|
@ -2,7 +2,6 @@
|
|||
#define _ASM_KPROBES_H
|
||||
/*
|
||||
* Kernel Probes (KProbes)
|
||||
* include/asm-x86_64/kprobes.h
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License as published by
|
||||
|
|
@ -20,6 +19,9 @@
|
|||
*
|
||||
* Copyright (C) IBM Corporation, 2002, 2004
|
||||
*
|
||||
* 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
|
||||
* Probes initial implementation ( includes suggestions from
|
||||
* Rusty Russell).
|
||||
* 2004-Oct Prasanna S Panchamukhi <prasanna@in.ibm.com> and Jim Keniston
|
||||
* kenistoj@us.ibm.com adopted from i386.
|
||||
*/
|
||||
|
|
@ -35,19 +37,22 @@ struct kprobe;
|
|||
typedef u8 kprobe_opcode_t;
|
||||
#define BREAKPOINT_INSTRUCTION 0xcc
|
||||
#define RELATIVEJUMP_INSTRUCTION 0xe9
|
||||
#define MAX_INSN_SIZE 15
|
||||
#define MAX_INSN_SIZE 16
|
||||
#define MAX_STACK_SIZE 64
|
||||
#define MIN_STACK_SIZE(ADDR) (((MAX_STACK_SIZE) < \
|
||||
(((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR))) \
|
||||
(((unsigned long)current_thread_info()) + THREAD_SIZE \
|
||||
- (unsigned long)(ADDR))) \
|
||||
? (MAX_STACK_SIZE) \
|
||||
: (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))
|
||||
: (((unsigned long)current_thread_info()) + THREAD_SIZE \
|
||||
- (unsigned long)(ADDR)))
|
||||
|
||||
#define ARCH_SUPPORTS_KRETPROBES
|
||||
#define flush_insn_slot(p) do { } while (0)
|
||||
|
||||
extern const int kretprobe_blacklist_size;
|
||||
|
||||
void arch_remove_kprobe(struct kprobe *p);
|
||||
void kretprobe_trampoline(void);
|
||||
extern void arch_remove_kprobe(struct kprobe *p);
|
||||
#define flush_insn_slot(p) do { } while (0)
|
||||
|
||||
/* Architecture specific copy of original instruction*/
|
||||
struct arch_specific_insn {
|
||||
|
|
@ -67,16 +72,16 @@ struct arch_specific_insn {
|
|||
struct prev_kprobe {
|
||||
struct kprobe *kp;
|
||||
unsigned long status;
|
||||
unsigned long old_rflags;
|
||||
unsigned long saved_rflags;
|
||||
unsigned long old_flags;
|
||||
unsigned long saved_flags;
|
||||
};
|
||||
|
||||
/* per-cpu kprobe control block */
|
||||
struct kprobe_ctlblk {
|
||||
unsigned long kprobe_status;
|
||||
unsigned long kprobe_old_rflags;
|
||||
unsigned long kprobe_saved_rflags;
|
||||
unsigned long *jprobe_saved_rsp;
|
||||
unsigned long kprobe_old_flags;
|
||||
unsigned long kprobe_saved_flags;
|
||||
unsigned long *jprobe_saved_sp;
|
||||
struct pt_regs jprobe_saved_regs;
|
||||
kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
|
||||
struct prev_kprobe prev_kprobe;
|
||||
|
|
@ -91,10 +96,7 @@ static inline void restore_interrupts(struct pt_regs *regs)
|
|||
local_irq_enable();
|
||||
}
|
||||
|
||||
extern int post_kprobe_handler(struct pt_regs *regs);
|
||||
extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
|
||||
extern int kprobe_handler(struct pt_regs *regs);
|
||||
|
||||
extern int kprobe_exceptions_notify(struct notifier_block *self,
|
||||
unsigned long val, void *data);
|
||||
#endif /* _ASM_KPROBES_H */
|
||||
|
|
|
|||
Loading…
Reference in New Issue