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x86: pass in pt_regs pointer for syscalls that need it

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Some syscalls need to access the pt_regs structure, either to copy
user register state or to modifiy it.  This patch adds stubs to load
the address of the pt_regs struct into the %eax register, and changes
the syscalls to regparm(1) to receive the pt_regs pointer as the
first argument.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Brian Gerst
2009-02-10 09:51:46 -05:00
committed by Ingo Molnar
parent aa78bcfa01
commit 253f29a4ae
8 changed files with 81 additions and 80 deletions
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35
arch/x86/kernel/signal.c
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@@ -549,39 +549,28 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
#endif /* CONFIG_X86_32 */
#ifdef CONFIG_X86_32
asmlinkage int sys_sigaltstack(unsigned long bx)
{
/*
* This is needed to make gcc realize it doesn't own the
* "struct pt_regs"
*/
struct pt_regs *regs = (struct pt_regs *)&bx;
const stack_t __user *uss = (const stack_t __user *)bx;
stack_t __user *uoss = (stack_t __user *)regs->cx;
return do_sigaltstack(uss, uoss, regs->sp);
}
ptregscall int
sys_sigaltstack(struct pt_regs *regs, const stack_t __user *uss,
stack_t __user *uoss)
#else /* !CONFIG_X86_32 */
asmlinkage long
sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
struct pt_regs *regs)
#endif /* CONFIG_X86_32 */
{
return do_sigaltstack(uss, uoss, regs->sp);
}
#endif /* CONFIG_X86_32 */
/*
* Do a signal return; undo the signal stack.
*/
#ifdef CONFIG_X86_32
asmlinkage unsigned long sys_sigreturn(unsigned long __unused)
ptregscall unsigned long sys_sigreturn(struct pt_regs *regs)
{
struct sigframe __user *frame;
struct pt_regs *regs;
unsigned long ax;
sigset_t set;
regs = (struct pt_regs *) &__unused;
frame = (struct sigframe __user *)(regs->sp - 8);
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
@@ -640,23 +629,13 @@ badframe:
}
#ifdef CONFIG_X86_32
/*
* Note: do not pass in pt_regs directly as with tail-call optimization
* GCC will incorrectly stomp on the caller's frame and corrupt user-space
* register state:
*/
asmlinkage int sys_rt_sigreturn(unsigned long __unused)
{
struct pt_regs *regs = (struct pt_regs *)&__unused;
return do_rt_sigreturn(regs);
}
ptregscall int sys_rt_sigreturn(struct pt_regs *regs)
#else /* !CONFIG_X86_32 */
asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
#endif /* CONFIG_X86_32 */
{
return do_rt_sigreturn(regs);
}
#endif /* CONFIG_X86_32 */
/*
* OK, we're invoking a handler: