From 9bbafce2eec190ef7e44b0eb1095ba17ce6ad3af Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Wed, 26 Mar 2008 19:02:47 +0900 Subject: [PATCH] sh: Fix occasional FPU register corruption under preempt. Presently with preempt enabled there's the possibility to be preempted after the TIF_USEDFPU test and the register save, leading to bogus state post-__switch_to(). Use an explicit preempt_disable()/enable() pair around unlazy_fpu()/clear_fpu() to avoid this. Follows the x86 change. Reported-by: Takuo Koguchi Signed-off-by: Paul Mundt --- arch/sh/kernel/cpu/sh2a/fpu.c | 1 + arch/sh/kernel/cpu/sh4/fpu.c | 1 + arch/sh/kernel/cpu/sh5/fpu.c | 1 + arch/sh/kernel/dump_task.c | 1 + arch/sh/kernel/process_32.c | 1 + arch/sh/kernel/signal_32.c | 1 + include/asm-sh/fpu.h | 32 ++++++++++++++++++-------------- include/asm-sh/processor.h | 1 - include/asm-sh/processor_32.h | 1 + include/asm-sh/processor_64.h | 1 + 10 files changed, 26 insertions(+), 15 deletions(-) diff --git a/arch/sh/kernel/cpu/sh2a/fpu.c b/arch/sh/kernel/cpu/sh2a/fpu.c index ff99562456..5627c0b3ff 100644 --- a/arch/sh/kernel/cpu/sh2a/fpu.c +++ b/arch/sh/kernel/cpu/sh2a/fpu.c @@ -13,6 +13,7 @@ #include #include #include +#include /* The PR (precision) bit in the FP Status Register must be clear when * an frchg instruction is executed, otherwise the instruction is undefined. diff --git a/arch/sh/kernel/cpu/sh4/fpu.c b/arch/sh/kernel/cpu/sh4/fpu.c index 817f9939cd..8020796139 100644 --- a/arch/sh/kernel/cpu/sh4/fpu.c +++ b/arch/sh/kernel/cpu/sh4/fpu.c @@ -16,6 +16,7 @@ #include #include #include +#include /* The PR (precision) bit in the FP Status Register must be clear when * an frchg instruction is executed, otherwise the instruction is undefined. diff --git a/arch/sh/kernel/cpu/sh5/fpu.c b/arch/sh/kernel/cpu/sh5/fpu.c index 30b76a94ab..dd4f51ffb5 100644 --- a/arch/sh/kernel/cpu/sh5/fpu.c +++ b/arch/sh/kernel/cpu/sh5/fpu.c @@ -17,6 +17,7 @@ #include #include #include +#include /* * Initially load the FPU with signalling NANS. This bit pattern diff --git a/arch/sh/kernel/dump_task.c b/arch/sh/kernel/dump_task.c index 4a8a4083ff..1db7ce0f25 100644 --- a/arch/sh/kernel/dump_task.c +++ b/arch/sh/kernel/dump_task.c @@ -1,5 +1,6 @@ #include #include +#include /* * Capture the user space registers if the task is not running (in user space) diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c index 9ab1926b9d..b98e37a1f5 100644 --- a/arch/sh/kernel/process_32.c +++ b/arch/sh/kernel/process_32.c @@ -25,6 +25,7 @@ #include #include #include +#include static int hlt_counter; int ubc_usercnt = 0; diff --git a/arch/sh/kernel/signal_32.c b/arch/sh/kernel/signal_32.c index f6b5fbfe75..f311551d9a 100644 --- a/arch/sh/kernel/signal_32.c +++ b/arch/sh/kernel/signal_32.c @@ -29,6 +29,7 @@ #include #include #include +#include #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) diff --git a/include/asm-sh/fpu.h b/include/asm-sh/fpu.h index f8429880a2..f89abf5920 100644 --- a/include/asm-sh/fpu.h +++ b/include/asm-sh/fpu.h @@ -1,9 +1,8 @@ #ifndef __ASM_SH_FPU_H #define __ASM_SH_FPU_H -#define SR_FD 0x00008000 - #ifndef __ASSEMBLY__ +#include #include #ifdef CONFIG_SH_FPU @@ -28,18 +27,23 @@ extern void save_fpu(struct task_struct *__tsk, struct pt_regs *regs); extern int do_fpu_inst(unsigned short, struct pt_regs *); -#define unlazy_fpu(tsk, regs) do { \ - if (test_tsk_thread_flag(tsk, TIF_USEDFPU)) { \ - save_fpu(tsk, regs); \ - } \ -} while (0) - -#define clear_fpu(tsk, regs) do { \ - if (test_tsk_thread_flag(tsk, TIF_USEDFPU)) { \ - clear_tsk_thread_flag(tsk, TIF_USEDFPU); \ - release_fpu(regs); \ - } \ -} while (0) +static inline void unlazy_fpu(struct task_struct *tsk, struct pt_regs *regs) +{ + preempt_disable(); + if (test_tsk_thread_flag(tsk, TIF_USEDFPU)) + save_fpu(tsk, regs); + preempt_enable(); +} + +static inline void clear_fpu(struct task_struct *tsk, struct pt_regs *regs) +{ + preempt_disable(); + if (test_tsk_thread_flag(tsk, TIF_USEDFPU)) { + clear_tsk_thread_flag(tsk, TIF_USEDFPU); + release_fpu(regs); + } + preempt_enable(); +} #endif /* __ASSEMBLY__ */ diff --git a/include/asm-sh/processor.h b/include/asm-sh/processor.h index 19fe47c1ca..ec707b98e5 100644 --- a/include/asm-sh/processor.h +++ b/include/asm-sh/processor.h @@ -2,7 +2,6 @@ #define __ASM_SH_PROCESSOR_H #include -#include #ifndef __ASSEMBLY__ /* diff --git a/include/asm-sh/processor_32.h b/include/asm-sh/processor_32.h index df2d5b039e..c09305d6a9 100644 --- a/include/asm-sh/processor_32.h +++ b/include/asm-sh/processor_32.h @@ -70,6 +70,7 @@ extern struct sh_cpuinfo cpu_data[]; */ #define SR_DSP 0x00001000 #define SR_IMASK 0x000000f0 +#define SR_FD 0x00008000 /* * FPU structure and data diff --git a/include/asm-sh/processor_64.h b/include/asm-sh/processor_64.h index eda4bef448..88a2edf8fa 100644 --- a/include/asm-sh/processor_64.h +++ b/include/asm-sh/processor_64.h @@ -112,6 +112,7 @@ extern struct sh_cpuinfo cpu_data[]; #endif #define SR_IMASK 0x000000f0 +#define SR_FD 0x00008000 #define SR_SSTEP 0x08000000 #ifndef __ASSEMBLY__ -- 2.39.5