diff options
Diffstat (limited to 'kernel/arch/x86/math-emu')
| -rw-r--r-- | kernel/arch/x86/math-emu/fpu_entry.c | 3 | ||||
| -rw-r--r-- | kernel/arch/x86/math-emu/fpu_system.h | 21 | ||||
| -rw-r--r-- | kernel/arch/x86/math-emu/get_address.c | 3 |
3 files changed, 20 insertions, 7 deletions
diff --git a/kernel/arch/x86/math-emu/fpu_entry.c b/kernel/arch/x86/math-emu/fpu_entry.c index 9b8681241..274a52b11 100644 --- a/kernel/arch/x86/math-emu/fpu_entry.c +++ b/kernel/arch/x86/math-emu/fpu_entry.c @@ -29,7 +29,6 @@ #include <asm/uaccess.h> #include <asm/traps.h> -#include <asm/desc.h> #include <asm/user.h> #include <asm/i387.h> @@ -185,7 +184,7 @@ void math_emulate(struct math_emu_info *info) math_abort(FPU_info, SIGILL); } - code_descriptor = LDT_DESCRIPTOR(FPU_CS); + code_descriptor = FPU_get_ldt_descriptor(FPU_CS); if (SEG_D_SIZE(code_descriptor)) { /* The above test may be wrong, the book is not clear */ /* Segmented 32 bit protected mode */ diff --git a/kernel/arch/x86/math-emu/fpu_system.h b/kernel/arch/x86/math-emu/fpu_system.h index 2c614410a..d342fce49 100644 --- a/kernel/arch/x86/math-emu/fpu_system.h +++ b/kernel/arch/x86/math-emu/fpu_system.h @@ -16,9 +16,24 @@ #include <linux/kernel.h> #include <linux/mm.h> -/* s is always from a cpu register, and the cpu does bounds checking - * during register load --> no further bounds checks needed */ -#define LDT_DESCRIPTOR(s) (((struct desc_struct *)current->mm->context.ldt)[(s) >> 3]) +#include <asm/desc.h> +#include <asm/mmu_context.h> + +static inline struct desc_struct FPU_get_ldt_descriptor(unsigned seg) +{ + static struct desc_struct zero_desc; + struct desc_struct ret = zero_desc; + +#ifdef CONFIG_MODIFY_LDT_SYSCALL + seg >>= 3; + mutex_lock(¤t->mm->context.lock); + if (current->mm->context.ldt && seg < current->mm->context.ldt->size) + ret = current->mm->context.ldt->entries[seg]; + mutex_unlock(¤t->mm->context.lock); +#endif + return ret; +} + #define SEG_D_SIZE(x) ((x).b & (3 << 21)) #define SEG_G_BIT(x) ((x).b & (1 << 23)) #define SEG_GRANULARITY(x) (((x).b & (1 << 23)) ? 4096 : 1) diff --git a/kernel/arch/x86/math-emu/get_address.c b/kernel/arch/x86/math-emu/get_address.c index 6ef5e9938..8300db71c 100644 --- a/kernel/arch/x86/math-emu/get_address.c +++ b/kernel/arch/x86/math-emu/get_address.c @@ -20,7 +20,6 @@ #include <linux/stddef.h> #include <asm/uaccess.h> -#include <asm/desc.h> #include "fpu_system.h" #include "exception.h" @@ -158,7 +157,7 @@ static long pm_address(u_char FPU_modrm, u_char segment, addr->selector = PM_REG_(segment); } - descriptor = LDT_DESCRIPTOR(PM_REG_(segment)); + descriptor = FPU_get_ldt_descriptor(addr->selector); base_address = SEG_BASE_ADDR(descriptor); address = base_address + offset; limit = base_address |