diff options
Diffstat (limited to 'arch/powerpc/kernel/signal_32.c')
| -rw-r--r-- | arch/powerpc/kernel/signal_32.c | 50 |
1 files changed, 38 insertions, 12 deletions
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index e6474a45cef5..2d47cc79e5b3 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -470,9 +470,9 @@ static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame, return 1; if (sigret) { - /* Set up the sigreturn trampoline: li r0,sigret; sc */ - if (__put_user(0x38000000UL + sigret, &frame->tramp[0]) - || __put_user(0x44000002UL, &frame->tramp[1])) + /* Set up the sigreturn trampoline: li 0,sigret; sc */ + if (__put_user(PPC_INST_ADDI + sigret, &frame->tramp[0]) + || __put_user(PPC_INST_SC, &frame->tramp[1])) return 1; flush_icache_range((unsigned long) &frame->tramp[0], (unsigned long) &frame->tramp[2]); @@ -619,9 +619,9 @@ static int save_tm_user_regs(struct pt_regs *regs, if (__put_user(msr, &frame->mc_gregs[PT_MSR])) return 1; if (sigret) { - /* Set up the sigreturn trampoline: li r0,sigret; sc */ - if (__put_user(0x38000000UL + sigret, &frame->tramp[0]) - || __put_user(0x44000002UL, &frame->tramp[1])) + /* Set up the sigreturn trampoline: li 0,sigret; sc */ + if (__put_user(PPC_INST_ADDI + sigret, &frame->tramp[0]) + || __put_user(PPC_INST_SC, &frame->tramp[1])) return 1; flush_icache_range((unsigned long) &frame->tramp[0], (unsigned long) &frame->tramp[2]); @@ -848,7 +848,23 @@ static long restore_tm_user_regs(struct pt_regs *regs, /* If TM bits are set to the reserved value, it's an invalid context */ if (MSR_TM_RESV(msr_hi)) return 1; - /* Pull in the MSR TM bits from the user context */ + + /* + * Disabling preemption, since it is unsafe to be preempted + * with MSR[TS] set without recheckpointing. + */ + preempt_disable(); + + /* + * CAUTION: + * After regs->MSR[TS] being updated, make sure that get_user(), + * put_user() or similar functions are *not* called. These + * functions can generate page faults which will cause the process + * to be de-scheduled with MSR[TS] set but without calling + * tm_recheckpoint(). This can cause a bug. + * + * Pull in the MSR TM bits from the user context + */ regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr_hi & MSR_TS_MASK); /* Now, recheckpoint. This loads up all of the checkpointed (older) * registers, including FP and V[S]Rs. After recheckpointing, the @@ -873,6 +889,8 @@ static long restore_tm_user_regs(struct pt_regs *regs, } #endif + preempt_enable(); + return 0; } #endif @@ -1140,11 +1158,11 @@ SYSCALL_DEFINE0(rt_sigreturn) { struct rt_sigframe __user *rt_sf; struct pt_regs *regs = current_pt_regs(); + int tm_restore = 0; #ifdef CONFIG_PPC_TRANSACTIONAL_MEM struct ucontext __user *uc_transact; unsigned long msr_hi; unsigned long tmp; - int tm_restore = 0; #endif /* Always make any pending restarted system calls return -EINTR */ current->restart_block.fn = do_no_restart_syscall; @@ -1192,11 +1210,19 @@ SYSCALL_DEFINE0(rt_sigreturn) goto bad; } } - if (!tm_restore) - /* Fall through, for non-TM restore */ + if (!tm_restore) { + /* + * Unset regs->msr because ucontext MSR TS is not + * set, and recheckpoint was not called. This avoid + * hitting a TM Bad thing at RFID + */ + regs->msr &= ~MSR_TS_MASK; + } + /* Fall through, for non-TM restore */ #endif - if (do_setcontext(&rt_sf->uc, regs, 1)) - goto bad; + if (!tm_restore) + if (do_setcontext(&rt_sf->uc, regs, 1)) + goto bad; /* * It's not clear whether or why it is desirable to save the |