diff options
Diffstat (limited to 'arch/powerpc/kernel/signal_64.c')
| -rw-r--r-- | arch/powerpc/kernel/signal_64.c | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index 979b9463e17b..b75bf6e74209 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -741,17 +741,35 @@ int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5, if (MSR_TM_ACTIVE(msr)) { /* We recheckpoint on return. */ struct ucontext __user *uc_transact; + + /* Trying to start TM on non TM system */ + if (!cpu_has_feature(CPU_FTR_TM)) + goto badframe; + if (__get_user(uc_transact, &uc->uc_link)) goto badframe; if (restore_tm_sigcontexts(current, &uc->uc_mcontext, &uc_transact->uc_mcontext)) goto badframe; - } - else - /* Fall through, for non-TM restore */ + } else #endif - if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext)) - goto badframe; + { + /* + * Fall through, for non-TM restore + * + * Unset MSR[TS] on the thread regs since MSR from user + * context does not have MSR active, and recheckpoint was + * not called since restore_tm_sigcontexts() was not called + * also. + * + * If not unsetting it, the code can RFID to userspace with + * MSR[TS] set, but without CPU in the proper state, + * causing a TM bad thing. + */ + current->thread.regs->msr &= ~MSR_TS_MASK; + if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext)) + goto badframe; + } if (restore_altstack(&uc->uc_stack)) goto badframe; |