diff options
author | Otavio Salvador <otavio@ossystems.com.br> | 2020-05-20 08:43:03 -0300 |
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committer | GitHub <noreply@github.com> | 2020-05-20 08:43:03 -0300 |
commit | 1279cd128bba968ebe0a2df7f7ae38bae90250ef (patch) | |
tree | df6b1a190760f51465122ca4c13492d5ac5984c6 /arch/powerpc/kernel/signal_64.c | |
parent | 0a8ab17689e628c84a666195bfc6ab85d11cf057 (diff) | |
parent | 2ae782ca839e0ee07de37122ddea362adff2e975 (diff) |
Merge pull request #76 from toradex/4.9-2.3.x-imx
4.9 2.3.x imx
Diffstat (limited to 'arch/powerpc/kernel/signal_64.c')
-rw-r--r-- | arch/powerpc/kernel/signal_64.c | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index d929afab7b24..aa6cc2bfa69d 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -469,8 +469,10 @@ static long restore_tm_sigcontexts(struct task_struct *tsk, err |= __get_user(tsk->thread.ckpt_regs.ccr, &sc->gp_regs[PT_CCR]); + /* Don't allow userspace to set the trap value */ + regs->trap = 0; + /* These regs are not checkpointed; they can go in 'regs'. */ - err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]); err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]); err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]); err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]); @@ -741,17 +743,35 @@ 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; |