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[PATCH] x86_64: Implement is_compat_task the right way

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By setting a flag during a 32bit system call only

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Andi Kleen 2006-01-11 22:44:06 +01:00 committed by Linus Torvalds
parent 2966387b48
commit bf2fcc6fdf
6 changed files with 16 additions and 1 deletions
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5
arch/x86_64/ia32/ia32entry.S
View file

@ -104,6 +104,7 @@ ENTRY(ia32_sysenter_target)
.quad 1b,ia32_badarg
.previous
GET_THREAD_INFO(%r10)
orl $TS_COMPAT,threadinfo_status(%r10)
testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP),threadinfo_flags(%r10)
CFI_REMEMBER_STATE
jnz sysenter_tracesys
@ -117,6 +118,7 @@ sysenter_do_call:
cli
testl $_TIF_ALLWORK_MASK,threadinfo_flags(%r10)
jnz int_ret_from_sys_call
andl $~TS_COMPAT,threadinfo_status(%r10)
/* clear IF, that popfq doesn't enable interrupts early */
andl $~0x200,EFLAGS-R11(%rsp)
RESTORE_ARGS 1,24,1,1,1,1
@ -203,6 +205,7 @@ ENTRY(ia32_cstar_target)
.quad 1b,ia32_badarg
.previous
GET_THREAD_INFO(%r10)
orl $TS_COMPAT,threadinfo_status(%r10)
testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP),threadinfo_flags(%r10)
CFI_REMEMBER_STATE
jnz cstar_tracesys
@ -216,6 +219,7 @@ cstar_do_call:
cli
testl $_TIF_ALLWORK_MASK,threadinfo_flags(%r10)
jnz int_ret_from_sys_call
andl $~TS_COMPAT,threadinfo_status(%r10)
RESTORE_ARGS 1,-ARG_SKIP,1,1,1
movl RIP-ARGOFFSET(%rsp),%ecx
CFI_REGISTER rip,rcx
@ -288,6 +292,7 @@ ENTRY(ia32_syscall)
this could be a problem. */
SAVE_ARGS 0,0,1
GET_THREAD_INFO(%r10)
orl $TS_COMPAT,threadinfo_status(%r10)
testl $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP),threadinfo_flags(%r10)
jnz ia32_tracesys
ia32_do_syscall:

1
arch/x86_64/kernel/asm-offsets.c
View file

@ -33,6 +33,7 @@ int main(void)
ENTRY(flags);
ENTRY(addr_limit);
ENTRY(preempt_count);
ENTRY(status);
BLANK();
#undef ENTRY
#define ENTRY(entry) DEFINE(pda_ ## entry, offsetof(struct x8664_pda, entry))

1
arch/x86_64/kernel/entry.S
View file

@ -313,6 +313,7 @@ int_with_check:
movl threadinfo_flags(%rcx),%edx
andl %edi,%edx
jnz int_careful
andl $~TS_COMPAT,threadinfo_status(%rcx)
jmp retint_swapgs
/* Either reschedule or signal or syscall exit tracking needed. */

4
drivers/input/evdev.c
View file

@ -154,8 +154,10 @@ struct input_event_compat {
__s32 value;
};
/* Note to the author of this code: did it ever occur to
you why the ifdefs are needed? Think about it again. -AK */
#ifdef CONFIG_X86_64
# define COMPAT_TEST test_thread_flag(TIF_IA32)
# define COMPAT_TEST is_compat_task()
#elif defined(CONFIG_IA64)
# define COMPAT_TEST IS_IA32_PROCESS(ia64_task_regs(current))
#elif defined(CONFIG_S390)

5
include/asm-x86_64/compat.h
View file

@ -202,4 +202,9 @@ static __inline__ void __user *compat_alloc_user_space(long len)
return (void __user *)regs->rsp - len;
}
static inline int is_compat_task(void)
{
return current_thread_info()->status & TS_COMPAT;
}
#endif /* _ASM_X86_64_COMPAT_H */

1
include/asm-x86_64/thread_info.h
View file

@ -138,6 +138,7 @@ static inline struct thread_info *stack_thread_info(void)
* have to worry about atomic accesses.
*/
#define TS_USEDFPU 0x0001 /* FPU was used by this task this quantum (SMP) */
#define TS_COMPAT 0x0002 /* 32bit syscall active */
#endif /* __KERNEL__ */