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author | Dave Airlie | 2017-11-02 03:40:41 +0100 |
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committer | Dave Airlie | 2017-11-02 03:40:41 +0100 |
commit | 7a88cbd8d65d622c00bd76ba4ae1d893b292c91c (patch) | |
tree | 826df7ac42ca13c33828d0142046186b91df686b /arch/powerpc/kernel/signal_64.c | |
parent | Merge tag 'drm-hisilicon-next-2017-11-01' of github.com:xin3liang/linux into ... (diff) | |
parent | Linux 4.14-rc7 (diff) | |
download | kernel-qcow2-linux-7a88cbd8d65d622c00bd76ba4ae1d893b292c91c.tar.gz kernel-qcow2-linux-7a88cbd8d65d622c00bd76ba4ae1d893b292c91c.tar.xz kernel-qcow2-linux-7a88cbd8d65d622c00bd76ba4ae1d893b292c91c.zip |
Backmerge tag 'v4.14-rc7' into drm-next
Linux 4.14-rc7
Requested by Ben Skeggs for nouveau to avoid major conflicts,
and things were getting a bit conflicty already, esp around amdgpu
reverts.
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 c83c115858c1..b2c002993d78 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); |