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authorPaul Mackerras <paulus@samba.org>2005-11-14 21:55:15 +1100
committerPaul Mackerras <paulus@samba.org>2005-11-15 11:11:32 +1100
commitcc657f53928997c65bf2409c45166c6ceee8d306 (patch)
tree247e16076381a947b4305bb6467acde1189f3918
parent493f25ef4087395891c99fcfe2c72e62e293e89f (diff)
downloadlinux-cc657f53928997c65bf2409c45166c6ceee8d306.tar.gz
powerpc: Fix clearing of the FPSCR when invoking a signal handler
As pointed out by Gary Byers, we were clearing the image of the FPSCR (floating point status and control register) in the thread_struct before copying it to the user stack when invoking a signal. Thus the task would see its FPSCR getting cleared when it took a signal. While fixing it I noticed that our swapcontext system call was also clearing FPSCR. It shouldn't, so I fixed that too. Signed-off-by: Paul Mackerras <paulus@samba.org>
-rw-r--r--arch/powerpc/kernel/signal_32.c7
-rw-r--r--arch/powerpc/kernel/signal_64.c6
2 files changed, 8 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index 8bdf95b7e4203e..5a2eba60dd390c 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -403,8 +403,6 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
ELF_NFPREG * sizeof(double)))
return 1;
- current->thread.fpscr.val = 0; /* turn off all fp exceptions */
-
#ifdef CONFIG_ALTIVEC
/* save altivec registers */
if (current->thread.used_vr) {
@@ -818,6 +816,9 @@ static int handle_rt_signal(unsigned long sig, struct k_sigaction *ka,
goto badframe;
regs->link = (unsigned long) frame->tramp;
}
+
+ current->thread.fpscr.val = 0; /* turn off all fp exceptions */
+
if (put_user(regs->gpr[1], (u32 __user *)newsp))
goto badframe;
regs->gpr[1] = newsp;
@@ -1097,6 +1098,8 @@ static int handle_signal(unsigned long sig, struct k_sigaction *ka,
regs->link = (unsigned long) frame->mctx.tramp;
}
+ current->thread.fpscr.val = 0; /* turn off all fp exceptions */
+
if (put_user(regs->gpr[1], (u32 __user *)newsp))
goto badframe;
regs->gpr[1] = newsp;
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 58194e15071199..1decf2785530e1 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -131,9 +131,6 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
flush_fp_to_thread(current);
- /* Make sure signal doesn't get spurrious FP exceptions */
- current->thread.fpscr.val = 0;
-
#ifdef CONFIG_ALTIVEC
err |= __put_user(v_regs, &sc->v_regs);
@@ -423,6 +420,9 @@ static int setup_rt_frame(int signr, struct k_sigaction *ka, siginfo_t *info,
if (err)
goto badframe;
+ /* Make sure signal handler doesn't get spurious FP exceptions */
+ current->thread.fpscr.val = 0;
+
/* Set up to return from userspace. */
if (vdso64_rt_sigtramp && current->thread.vdso_base) {
regs->link = current->thread.vdso_base + vdso64_rt_sigtramp;