OK, the patch was broken because it changed regs->regs[31] before the
setup_sigcontext. I think this one actually fixes a problem instead of
introducing one. :-) Somebody sent the 32-bit part of the patch around
a long time ago, but it doesn't seem to have gotten into CVS yet.
Kip
Kip Walker wrote:
>
> It looks like the RA setup by setup_frame and setup_rt_frame in
> arch/mips64/kernel/signal.c and signal32.c can be wrong. Same for
> arch/mips/kernel/signal.c
>
> signal32.c, 32-bit signal.c: sa_restorer is overriden
> signal.c: regs->regs[31] is pointed at the sigframe's code, even though
> there isn't code in the frame, and a comment says that sa_restorer is
> always used.
>
> Patch for 2.4 attached.
>
Index: arch/mips/kernel/signal.c
===================================================================
RCS file: /home/cvs/linux/arch/mips/kernel/signal.c,v
retrieving revision 1.39.2.9
diff -u -r1.39.2.9 signal.c
--- arch/mips/kernel/signal.c 5 Aug 2002 23:53:33 -0000 1.39.2.9
+++ arch/mips/kernel/signal.c 18 Oct 2002 15:52:26 -0000
@@ -461,6 +461,7 @@
int signr, sigset_t *set)
{
struct sigframe *frame;
+ unsigned long ra;
int err = 0;
frame = get_sigframe(ka, regs, sizeof(*frame));
@@ -470,7 +471,7 @@
/* Set up to return from userspace. If provided, use a stub already
in userspace. */
if (ka->sa.sa_flags & SA_RESTORER)
- regs->regs[31] = (unsigned long) ka->sa.sa_restorer;
+ ra = (unsigned long) ka->sa.sa_restorer;
else {
/*
* Set up the return code ...
@@ -483,6 +484,7 @@
err |= __put_user(0x0000000c ,
frame->sf_code + 1);
flush_cache_sigtramp((unsigned long) frame->sf_code);
+ ra = (unsigned long) frame->sf_code;
}
err |= setup_sigcontext(regs, &frame->sf_sc);
@@ -504,13 +506,13 @@
regs->regs[ 5] = 0;
regs->regs[ 6] = (unsigned long) &frame->sf_sc;
regs->regs[29] = (unsigned long) frame;
- regs->regs[31] = (unsigned long) frame->sf_code;
+ regs->regs[31] = ra;
regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
current->comm, current->pid,
- frame, regs->cp0_epc, frame->sf_code);
+ frame, regs->cp0_epc, regs->regs[31]);
#endif
return;
@@ -524,6 +526,7 @@
int signr, sigset_t *set, siginfo_t *info)
{
struct rt_sigframe *frame;
+ unsigned long ra;
int err = 0;
frame = get_sigframe(ka, regs, sizeof(*frame));
@@ -533,7 +536,7 @@
/* Set up to return from userspace. If provided, use a stub already
in userspace. */
if (ka->sa.sa_flags & SA_RESTORER)
- regs->regs[31] = (unsigned long) ka->sa.sa_restorer;
+ ra = (unsigned long) ka->sa.sa_restorer;
else {
/*
* Set up the return code ...
@@ -546,6 +549,7 @@
err |= __put_user(0x0000000c ,
frame->rs_code + 1);
flush_cache_sigtramp((unsigned long) frame->rs_code);
+ ra = (unsigned long) frame->rs_code;
}
/* Create siginfo. */
@@ -580,13 +584,13 @@
regs->regs[ 5] = (unsigned long) &frame->rs_info;
regs->regs[ 6] = (unsigned long) &frame->rs_uc;
regs->regs[29] = (unsigned long) frame;
- regs->regs[31] = (unsigned long) frame->rs_code;
+ regs->regs[31] = ra;
regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
current->comm, current->pid,
- frame, regs->cp0_epc, frame->rs_code);
+ frame, regs->cp0_epc, regs->regs[31]);
#endif
return;
Index: arch/mips64/kernel/signal.c
===================================================================
RCS file: /home/cvs/linux/arch/mips64/kernel/signal.c,v
retrieving revision 1.19.2.5
diff -u -r1.19.2.5 signal.c
--- arch/mips64/kernel/signal.c 18 Sep 2002 13:03:07 -0000 1.19.2.5
+++ arch/mips64/kernel/signal.c 18 Oct 2002 15:52:26 -0000
@@ -313,12 +313,6 @@
if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
goto give_sigsegv;
- /*
- * Set up to return from userspace. On mips64 we always use a stub
- * already provided by userspace and ignore SA_RESTORER.
- */
- regs->regs[31] = (unsigned long) ka->sa.sa_restorer;
-
err |= setup_sigcontext(regs, &frame->sf_sc);
err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
if (err)
@@ -331,20 +325,21 @@
* a1 = 0 (should be cause)
* a2 = pointer to struct sigcontext
*
- * $25 and c0_epc point to the signal handler, $29 points to the
- * struct sigframe.
+ * $25 and c0_epc point to the signal handler, $29 points to
+ * the struct sigframe. On mips64 we always use a stub
+ * already provided by userspace and ignore SA_RESTORER.
*/
regs->regs[ 4] = signr;
regs->regs[ 5] = 0;
regs->regs[ 6] = (unsigned long) &frame->sf_sc;
regs->regs[29] = (unsigned long) frame;
- regs->regs[31] = (unsigned long) frame->sf_code;
+ regs->regs[31] = (unsigned long) ka->sa.sa_restorer;
regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
current->comm, current->pid,
- frame, regs->cp0_epc, frame->sf_code);
+ frame, regs->cp0_epc, regs->regs[31]);
#endif
return;
@@ -364,12 +359,6 @@
if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
goto give_sigsegv;
- /*
- * Set up to return from userspace. On mips64 we always use a stub
- * already provided by userspace and ignore SA_RESTORER.
- */
- regs->regs[31] = (unsigned long) ka->sa.sa_restorer;
-
/* Create siginfo. */
err |= copy_siginfo_to_user(&frame->rs_info, info);
@@ -396,19 +385,20 @@
* a2 = pointer to ucontext
*
* $25 and c0_epc point to the signal handler, $29 points to
- * the struct rt_sigframe.
+ * the struct rt_sigframe. On mips64 we always use a stub
+ * already provided by userspace and ignore SA_RESTORER.
*/
regs->regs[ 4] = signr;
regs->regs[ 5] = (unsigned long) &frame->rs_info;
regs->regs[ 6] = (unsigned long) &frame->rs_uc;
regs->regs[29] = (unsigned long) frame;
- regs->regs[31] = (unsigned long) frame->rs_code;
+ regs->regs[31] = (unsigned long) ka->sa.sa_restorer;
regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
current->comm, current->pid,
- frame, regs->cp0_epc, frame->rs_code);
+ frame, regs->cp0_epc, regs->regs[31]);
#endif
return;
Index: arch/mips64/kernel/signal32.c
===================================================================
RCS file: /home/cvs/linux/arch/mips64/kernel/signal32.c,v
retrieving revision 1.20.2.9
diff -u -r1.20.2.9 signal32.c
--- arch/mips64/kernel/signal32.c 2 Oct 2002 12:21:45 -0000 1.20.2.9
+++ arch/mips64/kernel/signal32.c 18 Oct 2002 15:52:26 -0000
@@ -567,6 +567,7 @@
int signr, sigset_t *set)
{
struct sigframe *frame;
+ unsigned long ra;
int err = 0;
frame = get_sigframe(ka, regs, sizeof(*frame));
@@ -576,7 +577,7 @@
/* Set up to return from userspace. If provided, use a stub already
in userspace. */
if (ka->sa.sa_flags & SA_RESTORER)
- regs->regs[31] = (unsigned long) ka->sa.sa_restorer;
+ ra = (unsigned long) ka->sa.sa_restorer;
else {
/*
* Set up the return code ...
@@ -589,6 +590,7 @@
err |= __put_user(0x0000000c ,
frame->sf_code + 1);
flush_cache_sigtramp((unsigned long) frame->sf_code);
+ ra = (unsigned long) frame->sf_code;
}
err |= setup_sigcontext(regs, &frame->sf_sc);
@@ -610,13 +612,13 @@
regs->regs[ 5] = 0;
regs->regs[ 6] = (unsigned long) &frame->sf_sc;
regs->regs[29] = (unsigned long) frame;
- regs->regs[31] = (unsigned long) frame->sf_code;
+ regs->regs[31] = ra;
regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
current->comm, current->pid,
- frame, regs->cp0_epc, frame->sf_code);
+ frame, regs->cp0_epc, regs->regs[31]);
#endif
return;
@@ -631,6 +633,7 @@
sigset_t *set, siginfo_t *info)
{
struct rt_sigframe32 *frame;
+ unsigned long ra;
int err = 0;
frame = get_sigframe(ka, regs, sizeof(*frame));
@@ -640,7 +643,7 @@
/* Set up to return from userspace. If provided, use a stub already
in userspace. */
if (ka->sa.sa_flags & SA_RESTORER)
- regs->regs[31] = (unsigned long) ka->sa.sa_restorer;
+ ra = (unsigned long) ka->sa.sa_restorer;
else {
/*
* Set up the return code ...
@@ -653,6 +656,7 @@
err |= __put_user(0x0000000c ,
frame->rs_code + 1);
flush_cache_sigtramp((unsigned long) frame->rs_code);
+ ra = (unsigned long) frame->rs_code;
}
/* Convert (siginfo_t -> siginfo_t32) and copy to user. */
@@ -687,13 +691,13 @@
regs->regs[ 5] = (unsigned long) &frame->rs_info;
regs->regs[ 6] = (unsigned long) &frame->rs_uc;
regs->regs[29] = (unsigned long) frame;
- regs->regs[31] = (unsigned long) frame->rs_code;
+ regs->regs[31] = ra;
regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
#if DEBUG_SIG
printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
current->comm, current->pid,
- frame, regs->cp0_epc, frame->rs_code);
+ frame, regs->cp0_epc, regs->regs[31]);
#endif
return;
