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| author | Xie Xiaobo <xiaobo.xie@nxp.com> | 2017-12-12 08:12:33 (GMT) |
|---|---|---|
| committer | Xie Xiaobo <xiaobo.xie@nxp.com> | 2017-12-12 08:12:33 (GMT) |
| commit | c0246a9ec4d461ef4dd7647f94005380bb9e7f0b (patch) | |
| tree | 7588601aa6ce98f5e9fd083a1b351d9023c0b295 /arch/powerpc/kernel/signal_64.c | |
| parent | 50fd1a6d79d48a7c35890aecce5a5d6b872a461d (diff) | |
| parent | 56f4a560c6d6318b5a8e18a1b3e44909a5158d1e (diff) | |
| download | linux-c0246a9ec4d461ef4dd7647f94005380bb9e7f0b.tar.xz | |
Merge Linaro linux 4.9.62 into linux-4.9
Signed-off-by: Xiaobo Xie <xiaobo.xie@nxp.com>
Diffstat (limited to 'arch/powerpc/kernel/signal_64.c')
| -rw-r--r-- | arch/powerpc/kernel/signal_64.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index 96698fd..04e9225 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -452,9 +452,20 @@ static long restore_tm_sigcontexts(struct task_struct *tsk, if (MSR_TM_RESV(msr)) return -EINVAL; - /* pull in MSR TM from user context */ + /* pull in MSR TS bits from user context */ regs->msr = (regs->msr & ~MSR_TS_MASK) | (msr & MSR_TS_MASK); + /* + * Ensure that TM is enabled in regs->msr before we leave the signal + * handler. It could be the case that (a) user disabled the TM bit + * through the manipulation of the MSR bits in uc_mcontext or (b) the + * TM bit was disabled because a sufficient number of context switches + * happened whilst in the signal handler and load_tm overflowed, + * disabling the TM bit. In either case we can end up with an illegal + * TM state leading to a TM Bad Thing when we return to userspace. + */ + regs->msr |= MSR_TM; + /* pull in MSR LE from user context */ regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE); |