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| author | Paul Mackerras <paulus@samba.org> | 2005-11-30 13:20:54 +1100 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2005-11-30 13:20:54 +1100 |
| commit | 48abec07cf8063184d397560a6a5f27eaf9caddf (patch) | |
| tree | c96acc7a1176d1848d4c8c9f623f8ed39a1f63de /arch | |
| parent | 8117ce76c28ef0cab8545b518fa0543f6d1437e6 (diff) | |
| download | linux-3.10-48abec07cf8063184d397560a6a5f27eaf9caddf.tar.gz linux-3.10-48abec07cf8063184d397560a6a5f27eaf9caddf.tar.bz2 linux-3.10-48abec07cf8063184d397560a6a5f27eaf9caddf.zip | |
powerpc: Fix bug causing FP registers corruption on UP + preempt
This fixes a bug noticed by Paolo Galtieri and fixed for ARCH=ppc in
the previous commit (ppc: fix floating point register corruption).
This fixes the arch/powerpc code by adding preempt_disable/enable,
and also cleans it up a bit by pulling out the code that discards
any lazily-switched CPU register state into a new function, rather
than having that code repeated in three places.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 62 |
1 files changed, 25 insertions, 37 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index a5a7542a8ff..105d5609ff5 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -201,6 +201,28 @@ int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs) } #endif /* CONFIG_SPE */ +/* + * If we are doing lazy switching of CPU state (FP, altivec or SPE), + * and the current task has some state, discard it. + */ +static inline void discard_lazy_cpu_state(void) +{ +#ifndef CONFIG_SMP + preempt_disable(); + if (last_task_used_math == current) + last_task_used_math = NULL; +#ifdef CONFIG_ALTIVEC + if (last_task_used_altivec == current) + last_task_used_altivec = NULL; +#endif /* CONFIG_ALTIVEC */ +#ifdef CONFIG_SPE + if (last_task_used_spe == current) + last_task_used_spe = NULL; +#endif + preempt_enable(); +#endif /* CONFIG_SMP */ +} + int set_dabr(unsigned long dabr) { if (ppc_md.set_dabr) @@ -434,19 +456,7 @@ void show_regs(struct pt_regs * regs) void exit_thread(void) { kprobe_flush_task(current); - -#ifndef CONFIG_SMP - if (last_task_used_math == current) - last_task_used_math = NULL; -#ifdef CONFIG_ALTIVEC - if (last_task_used_altivec == current) - last_task_used_altivec = NULL; -#endif /* CONFIG_ALTIVEC */ -#ifdef CONFIG_SPE - if (last_task_used_spe == current) - last_task_used_spe = NULL; -#endif -#endif /* CONFIG_SMP */ + discard_lazy_cpu_state(); } void flush_thread(void) @@ -458,18 +468,7 @@ void flush_thread(void) t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT); #endif -#ifndef CONFIG_SMP - if (last_task_used_math == current) - last_task_used_math = NULL; -#ifdef CONFIG_ALTIVEC - if (last_task_used_altivec == current) - last_task_used_altivec = NULL; -#endif /* CONFIG_ALTIVEC */ -#ifdef CONFIG_SPE - if (last_task_used_spe == current) - last_task_used_spe = NULL; -#endif -#endif /* CONFIG_SMP */ + discard_lazy_cpu_state(); #ifdef CONFIG_PPC64 /* for now */ if (current->thread.dabr) { @@ -635,18 +634,7 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) } #endif -#ifndef CONFIG_SMP - if (last_task_used_math == current) - last_task_used_math = NULL; -#ifdef CONFIG_ALTIVEC - if (last_task_used_altivec == current) - last_task_used_altivec = NULL; -#endif -#ifdef CONFIG_SPE - if (last_task_used_spe == current) - last_task_used_spe = NULL; -#endif -#endif /* CONFIG_SMP */ + discard_lazy_cpu_state(); memset(current->thread.fpr, 0, sizeof(current->thread.fpr)); current->thread.fpscr.val = 0; #ifdef CONFIG_ALTIVEC |