From 8d460f6156cd55d981d109f01b82cbea8cf80e57 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Thu, 28 Jul 2016 10:57:31 +0800 Subject: [PATCH] powerpc/process: Add the function flush_tmregs_to_thread This patch creates a function flush_tmregs_to_thread which will then be used by subsequent patches in this series. The function checks for self tracing ptrace interface attempts while in the TM context and logs appropriate warning message. Signed-off-by: Anshuman Khandual Signed-off-by: Simon Guo Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/switch_to.h | 8 ++++++++ arch/powerpc/kernel/process.c | 20 ++++++++++++++++++++ 2 files changed, 28 insertions(+) diff --git a/arch/powerpc/include/asm/switch_to.h b/arch/powerpc/include/asm/switch_to.h index 17c8380673a6..0a74ebe934e1 100644 --- a/arch/powerpc/include/asm/switch_to.h +++ b/arch/powerpc/include/asm/switch_to.h @@ -75,6 +75,14 @@ static inline void disable_kernel_spe(void) static inline void __giveup_spe(struct task_struct *t) { } #endif +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +extern void flush_tmregs_to_thread(struct task_struct *); +#else +static inline void flush_tmregs_to_thread(struct task_struct *t) +{ +} +#endif + static inline void clear_task_ebb(struct task_struct *t) { #ifdef CONFIG_PPC_BOOK3S_64 diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 9ee2623e0f67..58ccf86415b4 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1074,6 +1074,26 @@ static inline void restore_sprs(struct thread_struct *old_thread, #endif } +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM +void flush_tmregs_to_thread(struct task_struct *tsk) +{ + /* + * Process self tracing is not yet supported through + * ptrace interface. Ptrace generic code should have + * prevented this from happening in the first place. + * Warn once here with the message, if some how it + * is attempted. + */ + WARN_ONCE(tsk == current, + "Not expecting ptrace on self: TM regs may be incorrect\n"); + + /* + * If task is not current, it should have been flushed + * already to it's thread_struct during __switch_to(). + */ +} +#endif + struct task_struct *__switch_to(struct task_struct *prev, struct task_struct *new) { -- 2.20.1