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kprobes/x86: Remove jprobe implementation 

Remove arch dependent setjump/longjump functions
and unused fields in kprobe_ctlblk for jprobes
from arch/x86.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/lkml/152942433578.15209.14034551799624757792.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Masami Hiramatsu 2018-06-20 01:05:35 +09:00 committed by Ingo Molnar
parent 5a6cf77f5e
commit 80006dbee6
2 changed files with 3 additions and 96 deletions
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3
arch/x86/include/asm/kprobes.h
View File

@ -111,9 +111,6 @@ struct kprobe_ctlblk {
unsigned long kprobe_status;
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;
};

96
arch/x86/kernel/kprobes/core.c
View File

@ -66,8 +66,6 @@
#include "common.h"
void jprobe_return_end(void);
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
@ -690,10 +688,9 @@ int kprobe_int3_handler(struct pt_regs *regs)
/*
* If we have no pre-handler or it returned 0, we
* continue with normal processing. If we have a
* pre-handler and it returned non-zero, it prepped
* for calling the break_handler below on re-entry
* for jprobe processing, so get out doing nothing
* more here.
* pre-handler and it returned non-zero, that means
* user handler setup registers to exit to another
* instruction, we must skip the single stepping.
*/
if (!p->pre_handler || !p->pre_handler(p, regs))
setup_singlestep(p, regs, kcb, 0);
@ -1083,93 +1080,6 @@ int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val,
}
NOKPROBE_SYMBOL(kprobe_exceptions_notify);
int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
{
struct jprobe *jp = container_of(p, struct jprobe, kp);
unsigned long addr;
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
kcb->jprobe_saved_regs = *regs;
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.
* tailcall optimization. So, to be absolutely safe
* we also save and restore enough stack bytes to cover
* the argument area.
* Use __memcpy() to avoid KASAN stack out-of-bounds reports as we copy
* raw stack chunk with redzones:
*/
__memcpy(kcb->jprobes_stack, (kprobe_opcode_t *)addr, MIN_STACK_SIZE(addr));
regs->ip = (unsigned long)(jp->entry);
/*
* jprobes use jprobe_return() which skips the normal return
* path of the function, and this messes up the accounting of the
* function graph tracer to get messed up.
*
* Pause function graph tracing while performing the jprobe function.
*/
pause_graph_tracing();
return 1;
}
NOKPROBE_SYMBOL(setjmp_pre_handler);
void jprobe_return(void)
{
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
/* Unpoison stack redzones in the frames we are going to jump over. */
kasan_unpoison_stack_above_sp_to(kcb->jprobe_saved_sp);
asm volatile (
#ifdef CONFIG_X86_64
" xchg %%rbx,%%rsp \n"
#else
" xchgl %%ebx,%%esp \n"
#endif
" int3 \n"
" .globl jprobe_return_end\n"
" jprobe_return_end: \n"
" nop \n"::"b"
(kcb->jprobe_saved_sp):"memory");
}
NOKPROBE_SYMBOL(jprobe_return);
NOKPROBE_SYMBOL(jprobe_return_end);
int longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
{
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
u8 *addr = (u8 *) (regs->ip - 1);
struct jprobe *jp = container_of(p, struct jprobe, kp);
void *saved_sp = kcb->jprobe_saved_sp;
if ((addr > (u8 *) jprobe_return) &&
(addr < (u8 *) jprobe_return_end)) {
if (stack_addr(regs) != saved_sp) {
struct pt_regs *saved_regs = &kcb->jprobe_saved_regs;
printk(KERN_ERR
"current sp %p does not match saved sp %p\n",
stack_addr(regs), saved_sp);
printk(KERN_ERR "Saved registers for jprobe %p\n", jp);
show_regs(saved_regs);
printk(KERN_ERR "Current registers\n");
show_regs(regs);
BUG();
}
/* It's OK to start function graph tracing again */
unpause_graph_tracing();
*regs = kcb->jprobe_saved_regs;
__memcpy(saved_sp, kcb->jprobes_stack, MIN_STACK_SIZE(saved_sp));
preempt_enable_no_resched();
return 1;
}
return 0;
}
NOKPROBE_SYMBOL(longjmp_break_handler);
bool arch_within_kprobe_blacklist(unsigned long addr)
{
bool is_in_entry_trampoline_section = false;