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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-28 00:39:29 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-28 00:39:29 +0300 |
commit | ed8780e3f2ecc82645342d070c6b4e530532e680 (patch) | |
tree | 3a9b69695e08bab76dc283286404b52ff8c3c1bc /arch/x86/kernel/alternative.c | |
parent | 8c2ab803e565f994b897573f6f2f6520eef41159 (diff) | |
parent | abee7c494d8c41bb388839bccc47e06247f0d7de (diff) | |
download | linux-ed8780e3f2ecc82645342d070c6b4e530532e680.tar.xz |
Merge tag 'x86-urgent-2020-10-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A couple of x86 fixes which missed rc1 due to my stupidity:
- Drop lazy TLB mode before switching to the temporary address space
for text patching.
text_poke() switches to the temporary mm which clears the lazy mode
and restores the original mm afterwards. Due to clearing lazy mode
this might restore a already dead mm if exit_mmap() runs in
parallel on another CPU.
- Document the x32 syscall design fail vs. syscall numbers 512-547
properly.
- Fix the ORC unwinder to handle the inactive task frame correctly.
This was unearthed due to the slightly different code generation of
gcc-10.
- Use an up to date screen_info for the boot params of kexec instead
of the possibly stale and invalid version which happened to be
valid when the kexec kernel was loaded"
* tag 'x86-urgent-2020-10-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/alternative: Don't call text_poke() in lazy TLB mode
x86/syscalls: Document the fact that syscalls 512-547 are a legacy mistake
x86/unwind/orc: Fix inactive tasks with stack pointer in %sp on GCC 10 compiled kernels
hyperv_fb: Update screen_info after removing old framebuffer
x86/kexec: Use up-to-dated screen_info copy to fill boot params
Diffstat (limited to 'arch/x86/kernel/alternative.c')
-rw-r--r-- | arch/x86/kernel/alternative.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 4adbe65afe23..2400ad62f330 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -807,6 +807,15 @@ static inline temp_mm_state_t use_temporary_mm(struct mm_struct *mm) temp_mm_state_t temp_state; lockdep_assert_irqs_disabled(); + + /* + * Make sure not to be in TLB lazy mode, as otherwise we'll end up + * with a stale address space WITHOUT being in lazy mode after + * restoring the previous mm. + */ + if (this_cpu_read(cpu_tlbstate.is_lazy)) + leave_mm(smp_processor_id()); + temp_state.mm = this_cpu_read(cpu_tlbstate.loaded_mm); switch_mm_irqs_off(NULL, mm, current); |