diff options
| author | Sebastian Andrzej Siewior | 2020-08-13 12:50:26 +0200 |
|---|---|---|
| committer | Thomas Gleixner | 2020-08-13 14:11:54 +0200 |
| commit | a6d996cbd38b42341ad3fce74506b9fdc280e395 (patch) | |
| tree | cee30c2db877ebcd6b10cafced5d9f62a888ee0f /arch/x86 | |
| parent | f29dfa53cc8ae6ad93bae619bcc0bf45cab344f7 (diff) | |
x86/alternatives: Acquire pte lock with interrupts enabled
pte lock is never acquired in-IRQ context so it does not require interrupts
to be disabled. The lock is a regular spinlock which cannot be acquired
with interrupts disabled on RT.
RT complains about pte_lock() in __text_poke() because it's invoked after
disabling interrupts.
__text_poke() has to disable interrupts as use_temporary_mm() expects
interrupts to be off because it invokes switch_mm_irqs_off() and uses
per-CPU (current active mm) data.
Move the PTE lock handling outside the interrupt disabled region.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by; Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20200813105026.bvugytmsso6muljw@linutronix.de
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/alternative.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index c826cddae157..34a1b8562c31 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -874,8 +874,6 @@ static void *__text_poke(void *addr, const void *opcode, size_t len) */ BUG_ON(!pages[0] || (cross_page_boundary && !pages[1])); - local_irq_save(flags); - /* * Map the page without the global bit, as TLB flushing is done with * flush_tlb_mm_range(), which is intended for non-global PTEs. @@ -892,6 +890,8 @@ static void *__text_poke(void *addr, const void *opcode, size_t len) */ VM_BUG_ON(!ptep); + local_irq_save(flags); + pte = mk_pte(pages[0], pgprot); set_pte_at(poking_mm, poking_addr, ptep, pte); @@ -941,8 +941,8 @@ static void *__text_poke(void *addr, const void *opcode, size_t len) */ BUG_ON(memcmp(addr, opcode, len)); - pte_unmap_unlock(ptep, ptl); local_irq_restore(flags); + pte_unmap_unlock(ptep, ptl); return addr; } |