From: akpm@osdl.org
To: torvalds@osdl.org
Cc: linux-arch@vger.kernel.org, akpm@osdl.org, ak@muc.de, mikpe@csd.uu.se
Subject: [patch 4/8] signal-race-fixes: x86-64 support
Date: Wed, 25 Aug 2004 14:30:11 -0700 [thread overview]
Message-ID: <200408252131.i7PLVt129265@mail.osdl.org> (raw)
From: Andi Kleen <ak@muc.de>
Add the signal race changes to x86-64 to make it compile again.
Didn't merge the more pointless changes from i386.
Also remove the special SA_ONESHOT handling, doesn't seem to be needed
anymore.
DESC
x86_64 signal handling fix
EDESC
From: Mikael Pettersson <mikpe@csd.uu.se>
The signal-race-fixes patch in 2.6.8-rc2-mm1 appears to have broken
x86-64's ia32 emulation.
When forcing a SIGSEGV the old code updated "*ka", where ka was a pointer
to current's k_sigaction for SIGSEGV. Now "ka_copy" points to a copy of
that structure, so assigning "*ka_copy" doesn't do what we want. Instead
do the assignment via current->... just like the normal signal delivery
code does.
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/arch/x86_64/ia32/ia32_signal.c | 38 +++++++++++++-------------
25-akpm/arch/x86_64/kernel/signal.c | 48 +++++++++++++++------------------
2 files changed, 42 insertions(+), 44 deletions(-)
diff -puN arch/x86_64/ia32/ia32_signal.c~signal-race-fix-x86_64 arch/x86_64/ia32/ia32_signal.c
--- 25/arch/x86_64/ia32/ia32_signal.c~signal-race-fix-x86_64 2004-08-25 14:26:48.950253936 -0700
+++ 25-akpm/arch/x86_64/ia32/ia32_signal.c 2004-08-25 14:26:48.956253024 -0700
@@ -394,7 +394,7 @@ ia32_setup_sigcontext(struct sigcontext_
* Determine which stack to use..
*/
static void __user *
-get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
+get_sigframe(struct k_sigaction *ka_copy, struct pt_regs *regs, size_t frame_size)
{
unsigned long rsp;
@@ -402,28 +402,28 @@ get_sigframe(struct k_sigaction *ka, str
rsp = regs->rsp;
/* This is the X/Open sanctioned signal stack switching. */
- if (ka->sa.sa_flags & SA_ONSTACK) {
+ if (ka_copy->sa.sa_flags & SA_ONSTACK) {
if (sas_ss_flags(rsp) == 0)
rsp = current->sas_ss_sp + current->sas_ss_size;
}
/* This is the legacy signal stack switching. */
else if ((regs->ss & 0xffff) != __USER_DS &&
- !(ka->sa.sa_flags & SA_RESTORER) &&
- ka->sa.sa_restorer) {
- rsp = (unsigned long) ka->sa.sa_restorer;
+ !(ka_copy->sa.sa_flags & SA_RESTORER) &&
+ ka_copy->sa.sa_restorer) {
+ rsp = (unsigned long)ka_copy->sa.sa_restorer;
}
return (void __user *)((rsp - frame_size) & -8UL);
}
-void ia32_setup_frame(int sig, struct k_sigaction *ka,
- compat_sigset_t *set, struct pt_regs * regs)
+void ia32_setup_frame(int sig, struct k_sigaction *ka_copy,
+ compat_sigset_t *set, struct pt_regs *regs)
{
struct sigframe __user *frame;
int err = 0;
- frame = get_sigframe(ka, regs, sizeof(*frame));
+ frame = get_sigframe(ka_copy, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
@@ -454,8 +454,8 @@ void ia32_setup_frame(int sig, struct k_
/* Return stub is in 32bit vsyscall page */
{
void __user *restorer = VSYSCALL32_SIGRETURN;
- if (ka->sa.sa_flags & SA_RESTORER)
- restorer = ka->sa.sa_restorer;
+ if (ka_copy->sa.sa_flags & SA_RESTORER)
+ restorer = ka_copy->sa.sa_restorer;
err |= __put_user(ptr_to_u32(restorer), &frame->pretcode);
}
/* These are actually not used anymore, but left because some
@@ -480,7 +480,7 @@ void ia32_setup_frame(int sig, struct k_
/* Set up registers for signal handler */
regs->rsp = (unsigned long) frame;
- regs->rip = (unsigned long) ka->sa.sa_handler;
+ regs->rip = (unsigned long) ka_copy->sa.sa_handler;
asm volatile("movl %0,%%ds" :: "r" (__USER32_DS));
asm volatile("movl %0,%%es" :: "r" (__USER32_DS));
@@ -500,17 +500,17 @@ void ia32_setup_frame(int sig, struct k_
give_sigsegv:
if (sig == SIGSEGV)
- ka->sa.sa_handler = SIG_DFL;
+ current->sighand->action[SIGSEGV-1].sa.sa_handler = SIG_DFL;
signal_fault(regs,frame,"32bit signal deliver");
}
-void ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
- compat_sigset_t *set, struct pt_regs * regs)
+void ia32_setup_rt_frame(int sig, struct k_sigaction *ka_copy,
+ siginfo_t *info, compat_sigset_t *set, struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
int err = 0;
- frame = get_sigframe(ka, regs, sizeof(*frame));
+ frame = get_sigframe(ka_copy, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
@@ -547,8 +547,8 @@ void ia32_setup_rt_frame(int sig, struct
{
void __user *restorer = VSYSCALL32_RTSIGRETURN;
- if (ka->sa.sa_flags & SA_RESTORER)
- restorer = ka->sa.sa_restorer;
+ if (ka_copy->sa.sa_flags & SA_RESTORER)
+ restorer = ka_copy->sa.sa_restorer;
err |= __put_user(ptr_to_u32(restorer), &frame->pretcode);
}
@@ -576,7 +576,7 @@ void ia32_setup_rt_frame(int sig, struct
/* Set up registers for signal handler */
regs->rsp = (unsigned long) frame;
- regs->rip = (unsigned long) ka->sa.sa_handler;
+ regs->rip = (unsigned long) ka_copy->sa.sa_handler;
asm volatile("movl %0,%%ds" :: "r" (__USER32_DS));
asm volatile("movl %0,%%es" :: "r" (__USER32_DS));
@@ -596,7 +596,7 @@ void ia32_setup_rt_frame(int sig, struct
give_sigsegv:
if (sig == SIGSEGV)
- ka->sa.sa_handler = SIG_DFL;
+ current->sighand->action[SIGSEGV-1].sa.sa_handler = SIG_DFL;
signal_fault(regs, frame, "32bit rt signal setup");
}
diff -puN arch/x86_64/kernel/signal.c~signal-race-fix-x86_64 arch/x86_64/kernel/signal.c
--- 25/arch/x86_64/kernel/signal.c~signal-race-fix-x86_64 2004-08-25 14:26:48.951253784 -0700
+++ 25-akpm/arch/x86_64/kernel/signal.c 2004-08-25 14:26:48.957252872 -0700
@@ -233,7 +233,8 @@ get_stack(struct k_sigaction *ka, struct
return (void __user *)round_down(rsp - size, 16);
}
-static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+static void setup_rt_frame(int sig, struct k_sigaction *ka_copy,
+ siginfo_t *info,
sigset_t *set, struct pt_regs * regs)
{
struct rt_sigframe __user *frame;
@@ -242,7 +243,7 @@ static void setup_rt_frame(int sig, stru
struct task_struct *me = current;
if (me->used_math) {
- fp = get_stack(ka, regs, sizeof(struct _fpstate));
+ fp = get_stack(ka_copy, regs, sizeof(struct _fpstate));
frame = (void __user *)round_down((unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate))) {
@@ -252,14 +253,14 @@ static void setup_rt_frame(int sig, stru
if (save_i387(fp) < 0)
err |= -1;
} else {
- frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8;
+ frame = get_stack(ka_copy, regs, sizeof(struct rt_sigframe)) - 8;
}
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) {
goto give_sigsegv;
}
- if (ka->sa.sa_flags & SA_SIGINFO) {
+ if (ka_copy->sa.sa_flags & SA_SIGINFO) {
err |= copy_siginfo_to_user(&frame->info, info);
if (err) {
goto give_sigsegv;
@@ -285,10 +286,10 @@ static void setup_rt_frame(int sig, stru
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
/* x86-64 should always use SA_RESTORER. */
- if (ka->sa.sa_flags & SA_RESTORER) {
- err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
+ if (ka_copy->sa.sa_flags & SA_RESTORER) {
+ err |= __put_user(ka_copy->sa.sa_restorer, &frame->pretcode);
} else {
- printk("%s forgot to set SA_RESTORER for signal %d.\n", me->comm, sig);
+ /* could use a vstub here */
goto give_sigsegv;
}
@@ -314,7 +315,7 @@ static void setup_rt_frame(int sig, stru
next argument after the signal number on the stack. */
regs->rsi = (unsigned long)&frame->info;
regs->rdx = (unsigned long)&frame->uc;
- regs->rip = (unsigned long) ka->sa.sa_handler;
+ regs->rip = (unsigned long) ka_copy->sa.sa_handler;
regs->rsp = (unsigned long)frame;
@@ -330,7 +331,7 @@ static void setup_rt_frame(int sig, stru
give_sigsegv:
if (sig == SIGSEGV)
- ka->sa.sa_handler = SIG_DFL;
+ current->sighand->action[SIGSEGV-1].sa.sa_handler = SIG_DFL;
signal_fault(regs,frame,"signal deliver");
}
@@ -339,11 +340,9 @@ give_sigsegv:
*/
static void
-handle_signal(unsigned long sig, siginfo_t *info, sigset_t *oldset,
- struct pt_regs * regs)
+handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka_copy,
+ sigset_t *oldset, struct pt_regs *regs)
{
- struct k_sigaction *ka = ¤t->sighand->action[sig-1];
-
#ifdef DEBUG_SIG
printk("handle_signal pid:%d sig:%lu rip:%lx rsp:%lx regs=%p\n", current->pid, sig,
regs->rip, regs->rsp, regs);
@@ -359,7 +358,7 @@ handle_signal(unsigned long sig, siginfo
break;
case -ERESTARTSYS:
- if (!(ka->sa.sa_flags & SA_RESTART)) {
+ if (!(ka_copy->sa.sa_flags & SA_RESTART)) {
regs->rax = -EINTR;
break;
}
@@ -372,20 +371,18 @@ handle_signal(unsigned long sig, siginfo
#ifdef CONFIG_IA32_EMULATION
if (test_thread_flag(TIF_IA32)) {
- if (ka->sa.sa_flags & SA_SIGINFO)
- ia32_setup_rt_frame(sig, ka, info, oldset, regs);
+ if (ka_copy->sa.sa_flags & SA_SIGINFO)
+ ia32_setup_rt_frame(sig, ka_copy, info, oldset, regs);
else
- ia32_setup_frame(sig, ka, oldset, regs);
+ ia32_setup_frame(sig, ka_copy, oldset, regs);
} else
#endif
- setup_rt_frame(sig, ka, info, oldset, regs);
-
- if (ka->sa.sa_flags & SA_ONESHOT)
- ka->sa.sa_handler = SIG_DFL;
+ setup_rt_frame(sig, ka_copy, info, oldset, regs);
- if (!(ka->sa.sa_flags & SA_NODEFER)) {
+ if (!(ka_copy->sa.sa_flags & SA_NODEFER)) {
spin_lock_irq(¤t->sighand->siglock);
- sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask);
+ sigorsets(¤t->blocked,¤t->blocked,
+ &ka_copy->sa.sa_mask);
sigaddset(¤t->blocked,sig);
recalc_sigpending();
spin_unlock_irq(¤t->sighand->siglock);
@@ -399,6 +396,7 @@ handle_signal(unsigned long sig, siginfo
*/
int do_signal(struct pt_regs *regs, sigset_t *oldset)
{
+ struct k_sigaction ka_copy;
siginfo_t info;
int signr;
@@ -420,7 +418,7 @@ int do_signal(struct pt_regs *regs, sigs
if (!oldset)
oldset = ¤t->blocked;
- signr = get_signal_to_deliver(&info, regs, NULL);
+ signr = get_signal_to_deliver(&info, &ka_copy, regs, NULL);
if (signr > 0) {
/* Reenable any watchpoints before delivering the
* signal to user space. The processor register will
@@ -431,7 +429,7 @@ int do_signal(struct pt_regs *regs, sigs
asm volatile("movq %0,%%db7" : : "r" (current->thread.debugreg7));
/* Whee! Actually deliver the signal. */
- handle_signal(signr, &info, oldset, regs);
+ handle_signal(signr, &info, &ka_copy, oldset, regs);
return 1;
}
_
next reply other threads:[~2004-08-25 21:32 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-08-25 21:30 akpm [this message]
-- strict thread matches above, loose matches on Subject: below --
2004-08-25 21:38 [patch 4/8] signal-race-fixes: x86-64 support akpm
2004-08-26 0:36 akpm
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