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Date: Thu, 18 Aug 2011 20:10:29 +0100
From: Al Viro <viro@....linux.org.uk>
To: richard@....at
Cc: user-mode-linux-devel@...ts.sourceforge.net,
linux-kernel@...r.kernel.org
Subject: Subject: [PATCH 69/91] um: no need to play with save_sp in signal frame setup anymore
Signed-off-by: Al Viro <viro@...iv.linux.org.uk>
---
arch/x86/um/signal_32.c | 39 ++++++++-------------------------------
arch/x86/um/signal_64.c | 33 +++++++--------------------------
2 files changed, 15 insertions(+), 57 deletions(-)
diff --git a/arch/x86/um/signal_32.c b/arch/x86/um/signal_32.c
index 2eebdc0..7a206d8 100644
--- a/arch/x86/um/signal_32.c
+++ b/arch/x86/um/signal_32.c
@@ -215,8 +215,7 @@ static int copy_sc_from_user(struct pt_regs *regs,
}
static int copy_sc_to_user(struct sigcontext __user *to,
- struct _fpstate __user *to_fp, struct pt_regs *regs,
- unsigned long sp)
+ struct _fpstate __user *to_fp, struct pt_regs *regs)
{
struct sigcontext sc;
struct faultinfo * fi = ¤t->thread.arch.faultinfo;
@@ -230,7 +229,7 @@ static int copy_sc_to_user(struct sigcontext __user *to,
sc.di = REGS_EDI(regs->regs.gp);
sc.si = REGS_ESI(regs->regs.gp);
sc.bp = REGS_EBP(regs->regs.gp);
- sc.sp = sp;
+ sc.sp = REGS_SP(regs->regs.gp);
sc.bx = REGS_EBX(regs->regs.gp);
sc.dx = REGS_EDX(regs->regs.gp);
sc.cx = REGS_ECX(regs->regs.gp);
@@ -291,7 +290,7 @@ static int copy_ucontext_to_user(struct ucontext __user *uc,
err |= put_user(current->sas_ss_sp, &uc->uc_stack.ss_sp);
err |= put_user(sas_ss_flags(sp), &uc->uc_stack.ss_flags);
err |= put_user(current->sas_ss_size, &uc->uc_stack.ss_size);
- err |= copy_sc_to_user(&uc->uc_mcontext, fp, ¤t->thread.regs, sp);
+ err |= copy_sc_to_user(&uc->uc_mcontext, fp, ¤t->thread.regs);
err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
return err;
}
@@ -324,7 +323,6 @@ int setup_signal_stack_sc(unsigned long stack_top, int sig,
{
struct sigframe __user *frame;
void __user *restorer;
- unsigned long save_sp = PT_REGS_SP(regs);
int err = 0;
/* This is the same calculation as i386 - ((sp + 4) & 15) == 0 */
@@ -337,19 +335,9 @@ int setup_signal_stack_sc(unsigned long stack_top, int sig,
if (ka->sa.sa_flags & SA_RESTORER)
restorer = ka->sa.sa_restorer;
- /* Update SP now because the page fault handler refuses to extend
- * the stack if the faulting address is too far below the current
- * SP, which frame now certainly is. If there's an error, the original
- * value is restored on the way out.
- * When writing the sigcontext to the stack, we have to write the
- * original value, so that's passed to copy_sc_to_user, which does
- * the right thing with it.
- */
- PT_REGS_SP(regs) = (unsigned long) frame;
-
err |= __put_user(restorer, &frame->pretcode);
err |= __put_user(sig, &frame->sig);
- err |= copy_sc_to_user(&frame->sc, NULL, regs, save_sp);
+ err |= copy_sc_to_user(&frame->sc, NULL, regs);
err |= __put_user(mask->sig[0], &frame->sc.oldmask);
if (_NSIG_WORDS > 1)
err |= __copy_to_user(&frame->extramask, &mask->sig[1],
@@ -367,7 +355,7 @@ int setup_signal_stack_sc(unsigned long stack_top, int sig,
err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));
if (err)
- goto err;
+ return err;
PT_REGS_SP(regs) = (unsigned long) frame;
PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler;
@@ -378,10 +366,6 @@ int setup_signal_stack_sc(unsigned long stack_top, int sig,
if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
ptrace_notify(SIGTRAP);
return 0;
-
-err:
- PT_REGS_SP(regs) = save_sp;
- return err;
}
int setup_signal_stack_si(unsigned long stack_top, int sig,
@@ -390,7 +374,6 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
{
struct rt_sigframe __user *frame;
void __user *restorer;
- unsigned long save_sp = PT_REGS_SP(regs);
int err = 0;
stack_top &= -8UL;
@@ -402,16 +385,13 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
if (ka->sa.sa_flags & SA_RESTORER)
restorer = ka->sa.sa_restorer;
- /* See comment above about why this is here */
- PT_REGS_SP(regs) = (unsigned long) frame;
-
err |= __put_user(restorer, &frame->pretcode);
err |= __put_user(sig, &frame->sig);
err |= __put_user(&frame->info, &frame->pinfo);
err |= __put_user(&frame->uc, &frame->puc);
err |= copy_siginfo_to_user(&frame->info, info);
err |= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask,
- save_sp);
+ PT_REGS_SP(regs));
/*
* This is movl $,%eax ; int $0x80
@@ -425,8 +405,9 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));
if (err)
- goto err;
+ return err;
+ PT_REGS_SP(regs) = (unsigned long) frame;
PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler;
PT_REGS_EAX(regs) = (unsigned long) sig;
PT_REGS_EDX(regs) = (unsigned long) &frame->info;
@@ -435,10 +416,6 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
ptrace_notify(SIGTRAP);
return 0;
-
-err:
- PT_REGS_SP(regs) = save_sp;
- return err;
}
long sys_sigreturn(struct pt_regs regs)
diff --git a/arch/x86/um/signal_64.c b/arch/x86/um/signal_64.c
index 4e5b9b0..74c2598 100644
--- a/arch/x86/um/signal_64.c
+++ b/arch/x86/um/signal_64.c
@@ -68,7 +68,7 @@ static int copy_sc_from_user(struct pt_regs *regs,
static int copy_sc_to_user(struct sigcontext __user *to,
struct _fpstate __user *to_fp, struct pt_regs *regs,
- unsigned long mask, unsigned long sp)
+ unsigned long mask)
{
struct faultinfo * fi = ¤t->thread.arch.faultinfo;
struct sigcontext sc;
@@ -81,11 +81,7 @@ static int copy_sc_to_user(struct sigcontext __user *to,
PUTREG(DI, di);
PUTREG(SI, si);
PUTREG(BP, bp);
- /*
- * Must use original RSP, which is passed in, rather than what's in
- * signal frame.
- */
- sc.sp = sp;
+ PUTREG(SP, sp);
PUTREG(BX, bx);
PUTREG(DX, dx);
PUTREG(CX, cx);
@@ -141,7 +137,6 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
siginfo_t *info, sigset_t *set)
{
struct rt_sigframe __user *frame;
- unsigned long save_sp = PT_REGS_RSP(regs);
int err = 0;
struct task_struct *me = current;
@@ -159,26 +154,15 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
goto out;
}
- /*
- * Update SP now because the page fault handler refuses to extend
- * the stack if the faulting address is too far below the current
- * SP, which frame now certainly is. If there's an error, the original
- * value is restored on the way out.
- * When writing the sigcontext to the stack, we have to write the
- * original value, so that's passed to copy_sc_to_user, which does
- * the right thing with it.
- */
- PT_REGS_RSP(regs) = (unsigned long) frame;
-
/* Create the ucontext. */
err |= __put_user(0, &frame->uc.uc_flags);
err |= __put_user(0, &frame->uc.uc_link);
err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
- err |= __put_user(sas_ss_flags(save_sp),
+ err |= __put_user(sas_ss_flags(PT_REGS_RSP(regs)),
&frame->uc.uc_stack.ss_flags);
err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
- set->sig[0], save_sp);
+ set->sig[0]);
err |= __put_user(&frame->fpstate, &frame->uc.uc_mcontext.fpstate);
if (sizeof(*set) == 16) {
__put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
@@ -197,10 +181,10 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
else
/* could use a vstub here */
- goto restore_sp;
+ return err;
if (err)
- goto restore_sp;
+ return err;
/* Set up registers for signal handler */
{
@@ -209,6 +193,7 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
sig = ed->signal_invmap[sig];
}
+ PT_REGS_RSP(regs) = (unsigned long) frame;
PT_REGS_RDI(regs) = sig;
/* In case the signal handler was declared without prototypes */
PT_REGS_RAX(regs) = 0;
@@ -222,10 +207,6 @@ int setup_signal_stack_si(unsigned long stack_top, int sig,
PT_REGS_RIP(regs) = (unsigned long) ka->sa.sa_handler;
out:
return err;
-
-restore_sp:
- PT_REGS_RSP(regs) = save_sp;
- return err;
}
long sys_rt_sigreturn(struct pt_regs *regs)
--
1.7.2.5
--
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