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Subject[RFC][PATCH v2 17/22] x86: setup_sigcontext(): list user_access_{begin,end}() into callers
Date
From: Al Viro <viro@zeniv.linux.org.uk>

Similar to ia32_setup_sigcontext() change several commits ago, make it
__always_inline. In cases when there is a user_access_{begin,end}()
section nearby, just move the call over there.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
arch/x86/kernel/signal.c | 45 ++++++++++++++++++++++++---------------------
1 file changed, 24 insertions(+), 21 deletions(-)

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 8b879fdc214c..f4fb00bd2378 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -140,12 +140,10 @@ static int restore_sigcontext(struct pt_regs *regs,
IS_ENABLED(CONFIG_X86_32));
}

-static int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
+static __always_inline int
+__unsafe_setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
struct pt_regs *regs, unsigned long mask)
{
- if (!user_access_begin(sc, sizeof(struct sigcontext)))
- return -EFAULT;
-
#ifdef CONFIG_X86_32
unsafe_put_user(get_user_gs(regs),
(unsigned int __user *)&sc->gs, Efault);
@@ -194,13 +192,17 @@ static int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
/* non-iBCS2 extensions.. */
unsafe_put_user(mask, &sc->oldmask, Efault);
unsafe_put_user(current->thread.cr2, &sc->cr2, Efault);
- user_access_end();
return 0;
Efault:
- user_access_end();
return -EFAULT;
}

+#define unsafe_put_sigcontext(sc, fp, regs, set, label) \
+do { \
+ if (__unsafe_setup_sigcontext(sc, fp, regs, set->sig[0])) \
+ goto label; \
+} while(0);
+
/*
* Set up a signal frame.
*/
@@ -301,9 +303,9 @@ __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
struct sigframe __user *frame;
void __user *restorer;
int err = 0;
- void __user *fpstate = NULL;
+ void __user *fp = NULL;

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

if (!access_ok(frame, sizeof(*frame)))
return -EFAULT;
@@ -311,8 +313,10 @@ __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
if (__put_user(sig, &frame->sig))
return -EFAULT;

- if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
+ if (!user_access_begin(&frame->sc, sizeof(struct sigcontext)))
return -EFAULT;
+ unsafe_put_sigcontext(&frame->sc, fp, regs, set, Efault);
+ user_access_end();

if (__put_user(set->sig[1], &frame->extramask[0]))
return -EFAULT;
@@ -353,6 +357,10 @@ __setup_frame(int sig, struct ksignal *ksig, sigset_t *set,
regs->cs = __USER_CS;

return 0;
+
+Efault:
+ user_access_end();
+ return -EFAULT;
}

static int __setup_rt_frame(int sig, struct ksignal *ksig,
@@ -361,9 +369,9 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
struct rt_sigframe __user *frame;
void __user *restorer;
int err = 0;
- void __user *fpstate = NULL;
+ void __user *fp = NULL;

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

if (!user_access_begin(frame, sizeof(*frame)))
return -EFAULT;
@@ -395,13 +403,11 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
* signal handler stack frames.
*/
unsafe_put_user(*((u64 *)&rt_retcode), (u64 *)frame->retcode, Efault);
+ unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault);
user_access_end();

err |= copy_siginfo_to_user(&frame->info, &ksig->info);
- err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
- regs, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
-
if (err)
return -EFAULT;

@@ -472,9 +478,8 @@ static int __setup_rt_frame(int sig, struct ksignal *ksig,
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
unsafe_put_user(ksig->ka.sa.sa_restorer, &frame->pretcode, Efault);
+ unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault);
user_access_end();
-
- err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
err |= __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);

if (err)
@@ -532,12 +537,12 @@ static int x32_setup_rt_frame(struct ksignal *ksig,
unsigned long uc_flags;
void __user *restorer;
int err = 0;
- void __user *fpstate = NULL;
+ void __user *fp = NULL;

if (!(ksig->ka.sa.sa_flags & SA_RESTORER))
return -EFAULT;

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

if (!access_ok(frame, sizeof(*frame)))
return -EFAULT;
@@ -559,10 +564,8 @@ static int x32_setup_rt_frame(struct ksignal *ksig,
unsafe_put_user(0, &frame->uc.uc__pad0, Efault);
restorer = ksig->ka.sa.sa_restorer;
unsafe_put_user(restorer, (unsigned long __user *)&frame->pretcode, Efault);
+ unsafe_put_sigcontext(&frame->uc.uc_mcontext, fp, regs, set, Efault);
user_access_end();
-
- err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
- regs, set->sig[0]);
err |= __put_user(*(__u64 *)set, (__u64 __user *)&frame->uc.uc_sigmask);

if (err)
--
2.11.0
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