From 64b163fab684e3de47aa8db6cc08ae7d2e194373 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 28 Aug 2017 08:47:37 +0200 Subject: [PATCH] x86/idt: Unify gate_struct handling for 32/64-bit kernels The first 32 bits of gate struct are the same for 32 and 64 bit kernels. The 32-bit version uses desc_struct and no designated data structure, so we need different accessors for 32 and 64 bit kernels. Aside of that the macros which are necessary to build the 32-bit gate descriptor are horrible to read. Unify the gate structs and switch all code fiddling with it over. Signed-off-by: Thomas Gleixner Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20170828064957.861974317@linutronix.de Signed-off-by: Ingo Molnar --- arch/x86/boot/compressed/eboot.c | 8 ++--- arch/x86/include/asm/desc.h | 45 +++++++++++-------------- arch/x86/include/asm/desc_defs.h | 57 +++++++++++++++++++++----------- arch/x86/kvm/vmx.c | 2 +- arch/x86/xen/enlighten_pv.c | 12 +++---- 5 files changed, 67 insertions(+), 57 deletions(-) diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c index c3e869eaef0c..65f0b24f60db 100644 --- a/arch/x86/boot/compressed/eboot.c +++ b/arch/x86/boot/compressed/eboot.c @@ -1058,7 +1058,7 @@ struct boot_params *efi_main(struct efi_config *c, desc->s = DESC_TYPE_CODE_DATA; desc->dpl = 0; desc->p = 1; - desc->limit = 0xf; + desc->limit1 = 0xf; desc->avl = 0; desc->l = 0; desc->d = SEG_OP_SIZE_32BIT; @@ -1078,7 +1078,7 @@ struct boot_params *efi_main(struct efi_config *c, desc->s = DESC_TYPE_CODE_DATA; desc->dpl = 0; desc->p = 1; - desc->limit = 0xf; + desc->limit1 = 0xf; desc->avl = 0; if (IS_ENABLED(CONFIG_X86_64)) { desc->l = 1; @@ -1099,7 +1099,7 @@ struct boot_params *efi_main(struct efi_config *c, desc->s = DESC_TYPE_CODE_DATA; desc->dpl = 0; desc->p = 1; - desc->limit = 0xf; + desc->limit1 = 0xf; desc->avl = 0; desc->l = 0; desc->d = SEG_OP_SIZE_32BIT; @@ -1116,7 +1116,7 @@ struct boot_params *efi_main(struct efi_config *c, desc->s = 0; desc->dpl = 0; desc->p = 1; - desc->limit = 0x0; + desc->limit1 = 0x0; desc->avl = 0; desc->l = 0; desc->d = 0; diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h index d18a604a0941..0731064c633b 100644 --- a/arch/x86/include/asm/desc.h +++ b/arch/x86/include/asm/desc.h @@ -84,33 +84,25 @@ static inline phys_addr_t get_cpu_gdt_paddr(unsigned int cpu) return per_cpu_ptr_to_phys(get_cpu_gdt_rw(cpu)); } -#ifdef CONFIG_X86_64 - static inline void pack_gate(gate_desc *gate, unsigned type, unsigned long func, unsigned dpl, unsigned ist, unsigned seg) { - gate->offset_low = PTR_LOW(func); + gate->offset_low = (u16) func; + gate->bits.p = 1; + gate->bits.dpl = dpl; + gate->bits.zero = 0; + gate->bits.type = type; + gate->offset_middle = (u16) (func >> 16); +#ifdef CONFIG_X86_64 gate->segment = __KERNEL_CS; - gate->ist = ist; - gate->p = 1; - gate->dpl = dpl; - gate->zero0 = 0; - gate->zero1 = 0; - gate->type = type; - gate->offset_middle = PTR_MIDDLE(func); - gate->offset_high = PTR_HIGH(func); -} - + gate->bits.ist = ist; + gate->reserved = 0; + gate->offset_high = (u32) (func >> 32); #else -static inline void pack_gate(gate_desc *gate, unsigned char type, - unsigned long base, unsigned dpl, unsigned flags, - unsigned short seg) -{ - gate->a = (seg << 16) | (base & 0xffff); - gate->b = (base & 0xffff0000) | (((0x80 | type | (dpl << 5)) & 0xff) << 8); -} - + gate->segment = seg; + gate->bits.ist = 0; #endif +} static inline int desc_empty(const void *ptr) { @@ -186,7 +178,8 @@ static inline void pack_descriptor(struct desc_struct *desc, unsigned long base, } -static inline void set_tssldt_descriptor(void *d, unsigned long addr, unsigned type, unsigned size) +static inline void set_tssldt_descriptor(void *d, unsigned long addr, + unsigned type, unsigned size) { #ifdef CONFIG_X86_64 struct ldttss_desc64 *desc = d; @@ -194,13 +187,13 @@ static inline void set_tssldt_descriptor(void *d, unsigned long addr, unsigned t memset(desc, 0, sizeof(*desc)); desc->limit0 = size & 0xFFFF; - desc->base0 = PTR_LOW(addr); - desc->base1 = PTR_MIDDLE(addr) & 0xFF; + desc->base0 = (u16) addr; + desc->base1 = (addr >> 16) & 0xFF; desc->type = type; desc->p = 1; desc->limit1 = (size >> 16) & 0xF; - desc->base2 = (PTR_MIDDLE(addr) >> 8) & 0xFF; - desc->base3 = PTR_HIGH(addr); + desc->base2 = (addr >> 24) & 0xFF; + desc->base3 = (u32) (addr >> 32); #else pack_descriptor((struct desc_struct *)d, addr, size, 0x80 | type, 0); #endif diff --git a/arch/x86/include/asm/desc_defs.h b/arch/x86/include/asm/desc_defs.h index 49265345d4d2..d684bee8a59a 100644 --- a/arch/x86/include/asm/desc_defs.h +++ b/arch/x86/include/asm/desc_defs.h @@ -47,20 +47,6 @@ enum { GATE_TASK = 0x5, }; -/* 16byte gate */ -struct gate_struct64 { - u16 offset_low; - u16 segment; - unsigned ist : 3, zero0 : 5, type : 5, dpl : 2, p : 1; - u16 offset_middle; - u32 offset_high; - u32 zero1; -} __attribute__((packed)); - -#define PTR_LOW(x) ((unsigned long long)(x) & 0xFFFF) -#define PTR_MIDDLE(x) (((unsigned long long)(x) >> 16) & 0xFFFF) -#define PTR_HIGH(x) ((unsigned long long)(x) >> 32) - enum { DESC_TSS = 0x9, DESC_LDT = 0x2, @@ -77,20 +63,51 @@ struct ldttss_desc64 { u32 zero1; } __attribute__((packed)); + #ifdef CONFIG_X86_64 -typedef struct gate_struct64 gate_desc; typedef struct ldttss_desc64 ldt_desc; typedef struct ldttss_desc64 tss_desc; -#define gate_offset(g) ((g).offset_low | ((unsigned long)(g).offset_middle << 16) | ((unsigned long)(g).offset_high << 32)) -#define gate_segment(g) ((g).segment) #else -typedef struct desc_struct gate_desc; typedef struct desc_struct ldt_desc; typedef struct desc_struct tss_desc; -#define gate_offset(g) (((g).b & 0xffff0000) | ((g).a & 0x0000ffff)) -#define gate_segment(g) ((g).a >> 16) #endif +struct idt_bits { + u16 ist : 3, + zero : 5, + type : 5, + dpl : 2, + p : 1; +} __attribute__((packed)); + +struct gate_struct { + u16 offset_low; + u16 segment; + struct idt_bits bits; + u16 offset_middle; +#ifdef CONFIG_X86_64 + u32 offset_high; + u32 reserved; +#endif +} __attribute__((packed)); + +typedef struct gate_struct gate_desc; + +static inline unsigned long gate_offset(const gate_desc *g) +{ +#ifdef CONFIG_X86_64 + return g->offset_low | ((unsigned long)g->offset_middle << 16) | + ((unsigned long) g->offset_high << 32); +#else + return g->offset_low | ((unsigned long)g->offset_middle << 16); +#endif +} + +static inline unsigned long gate_segment(const gate_desc *g) +{ + return g->segment; +} + struct desc_ptr { unsigned short size; unsigned long address; diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c6ef2940119b..08d00eefabea 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -8779,7 +8779,7 @@ static void vmx_handle_external_intr(struct kvm_vcpu *vcpu) vector = exit_intr_info & INTR_INFO_VECTOR_MASK; desc = (gate_desc *)vmx->host_idt_base + vector; - entry = gate_offset(*desc); + entry = gate_offset(desc); asm volatile( #ifdef CONFIG_X86_64 "mov %%" _ASM_SP ", %[sp]\n\t" diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index 98491521bb43..4c5d72b8aada 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -584,12 +584,12 @@ static int cvt_gate_to_trap(int vector, const gate_desc *val, { unsigned long addr; - if (val->type != GATE_TRAP && val->type != GATE_INTERRUPT) + if (val->bits.type != GATE_TRAP && val->bits.type != GATE_INTERRUPT) return 0; info->vector = vector; - addr = gate_offset(*val); + addr = gate_offset(val); #ifdef CONFIG_X86_64 /* * Look for known traps using IST, and substitute them @@ -622,16 +622,16 @@ static int cvt_gate_to_trap(int vector, const gate_desc *val, ; else { /* Some other trap using IST? */ - if (WARN_ON(val->ist != 0)) + if (WARN_ON(val->bits.ist != 0)) return 0; } #endif /* CONFIG_X86_64 */ info->address = addr; - info->cs = gate_segment(*val); - info->flags = val->dpl; + info->cs = gate_segment(val); + info->flags = val->bits.dpl; /* interrupt gates clear IF */ - if (val->type == GATE_INTERRUPT) + if (val->bits.type == GATE_INTERRUPT) info->flags |= 1 << 2; return 1;