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authorPaolo Galtieri <pgaltieri@mvista.com>2005-11-29 19:34:38 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2005-11-29 19:47:03 -0800
commit9f232a125bf86b0dae09f8ea4a0553535cf6b658 (patch)
tree2ba12b9889cef8568ae9ce04b8672162fa2283ff
parent123d3c13e2853a11b4d599d754b356acb12886e2 (diff)
downloadop-kernel-dev-9f232a125bf86b0dae09f8ea4a0553535cf6b658.zip
op-kernel-dev-9f232a125bf86b0dae09f8ea4a0553535cf6b658.tar.gz
[PATCH] ppc: fix floating point register corruption
I recently discovered a bug on PPC which causes the floating point registers to get corrupted when CONFIG_PREEMPT=y. The problem occurred while running a multi threaded Java application that does floating point. The problem could be reproduced in anywhere from 2 to 6 hours. With the patch I have included below it ran for over a week without failure. Signed-off-by: Paolo Galtieri <pgaltieri@mvista.com> Cc: Kumar Gala <galak@gate.crashing.org> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Tom Rini <trini@kernel.crashing.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--arch/ppc/kernel/process.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/ppc/kernel/process.c b/arch/ppc/kernel/process.c
index cb1c7b9..25cbdc8 100644
--- a/arch/ppc/kernel/process.c
+++ b/arch/ppc/kernel/process.c
@@ -417,6 +417,7 @@ void show_regs(struct pt_regs * regs)
void exit_thread(void)
{
+ preempt_disable();
if (last_task_used_math == current)
last_task_used_math = NULL;
if (last_task_used_altivec == current)
@@ -425,10 +426,12 @@ void exit_thread(void)
if (last_task_used_spe == current)
last_task_used_spe = NULL;
#endif
+ preempt_enable();
}
void flush_thread(void)
{
+ preempt_disable();
if (last_task_used_math == current)
last_task_used_math = NULL;
if (last_task_used_altivec == current)
@@ -437,6 +440,7 @@ void flush_thread(void)
if (last_task_used_spe == current)
last_task_used_spe = NULL;
#endif
+ preempt_enable();
}
void
@@ -535,6 +539,7 @@ void start_thread(struct pt_regs *regs, unsigned long nip, unsigned long sp)
regs->nip = nip;
regs->gpr[1] = sp;
regs->msr = MSR_USER;
+ preempt_disable();
if (last_task_used_math == current)
last_task_used_math = NULL;
if (last_task_used_altivec == current)
@@ -543,6 +548,7 @@ void start_thread(struct pt_regs *regs, unsigned long nip, unsigned long sp)
if (last_task_used_spe == current)
last_task_used_spe = NULL;
#endif
+ preempt_enable();
memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
current->thread.fpscr.val = 0;
#ifdef CONFIG_ALTIVEC
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