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Subject[RFC][PATCH 18/22] x86: __setup_frame(): consolidate uaccess areas
Date
From: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
arch/x86/kernel/signal.c | 23 ++++++-----------------
1 file changed, 6 insertions(+), 17 deletions(-)

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index a5a898c3c574..02b81784acc7 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -295,26 +295,17 @@ __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
{
struct sigframe __user *frame;
void __user *restorer;
- int err = 0;
void __user *fpstate = NULL;

frame = get_sigframe(&ksig->ka, regs, sizeof(*frame), &fpstate);

- if (!access_ok(frame, sizeof(*frame)))
- return -EFAULT;
-
- if (__put_user(sig, &frame->sig))
+ if (!user_access_begin(frame, sizeof(*frame)))
return -EFAULT;

- if (!user_access_begin(&frame->sc, sizeof(struct sigcontext)))
- return -EFAULT;
+ unsafe_put_user(sig, &frame->sig, Efault);
if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
goto Efault;
- user_access_end();
-
- if (__put_user(set->sig[1], &frame->extramask[0]))
- return -EFAULT;
-
+ unsafe_put_user(set->sig[1], &frame->extramask[0], Efault);
if (current->mm->context.vdso)
restorer = current->mm->context.vdso +
vdso_image_32.sym___kernel_sigreturn;
@@ -324,7 +315,7 @@ __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
restorer = ksig->ka.sa.sa_restorer;

/* Set up to return from userspace. */
- err |= __put_user(restorer, &frame->pretcode);
+ unsafe_put_user(restorer, &frame->pretcode, Efault);

/*
* This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
@@ -333,10 +324,8 @@ __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
* reasons and because gdb uses it as a signature to notice
* signal handler stack frames.
*/
- err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode);
-
- if (err)
- return -EFAULT;
+ unsafe_put_user(*((u64 *)&retcode), (u64 *)frame->retcode, Efault);
+ user_access_end();

/* Set up registers for signal handler */
regs->sp = (unsigned long)frame;
--
2.11.0
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