diff options
Diffstat (limited to 'arch/powerpc/kernel/signal.c')
| -rw-r--r-- | arch/powerpc/kernel/signal.c | 40 |
1 files changed, 38 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c index 577a8aa69c6e..457e97aa2945 100644 --- a/arch/powerpc/kernel/signal.c +++ b/arch/powerpc/kernel/signal.c @@ -18,6 +18,7 @@ #include <asm/uaccess.h> #include <asm/unistd.h> #include <asm/debug.h> +#include <asm/tm.h> #include "signal.h" @@ -30,13 +31,13 @@ int show_unhandled_signals = 1; /* * Allocate space for the signal frame */ -void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, +void __user * get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size, int is_32) { unsigned long oldsp, newsp; /* Default to using normal stack */ - oldsp = get_clean_sp(regs, is_32); + oldsp = get_clean_sp(sp, is_32); /* Check for alt stack */ if ((ka->sa.sa_flags & SA_ONSTACK) && @@ -175,3 +176,38 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags) user_enter(); } + +unsigned long get_tm_stackpointer(struct pt_regs *regs) +{ + /* When in an active transaction that takes a signal, we need to be + * careful with the stack. It's possible that the stack has moved back + * up after the tbegin. The obvious case here is when the tbegin is + * called inside a function that returns before a tend. In this case, + * the stack is part of the checkpointed transactional memory state. + * If we write over this non transactionally or in suspend, we are in + * trouble because if we get a tm abort, the program counter and stack + * pointer will be back at the tbegin but our in memory stack won't be + * valid anymore. + * + * To avoid this, when taking a signal in an active transaction, we + * need to use the stack pointer from the checkpointed state, rather + * than the speculated state. This ensures that the signal context + * (written tm suspended) will be written below the stack required for + * the rollback. The transaction is aborted becuase of the treclaim, + * so any memory written between the tbegin and the signal will be + * rolled back anyway. + * + * For signals taken in non-TM or suspended mode, we use the + * normal/non-checkpointed stack pointer. + */ + +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + if (MSR_TM_ACTIVE(regs->msr)) { + tm_enable(); + tm_reclaim(¤t->thread, regs->msr, TM_CAUSE_SIGNAL); + if (MSR_TM_TRANSACTIONAL(regs->msr)) + return current->thread.ckpt_regs.gpr[1]; + } +#endif + return regs->gpr[1]; +} |