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| author | Paolo Galtieri <pgaltieri@mvista.com> | 2005-11-29 19:34:38 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-29 19:47:03 -0800 |
| commit | 9f232a125bf86b0dae09f8ea4a0553535cf6b658 (patch) | |
| tree | 2ba12b9889cef8568ae9ce04b8672162fa2283ff | |
| parent | 123d3c13e2853a11b4d599d754b356acb12886e2 (diff) | |
| download | op-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.c | 6 |
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 |
