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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-05-24 10:21:02 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-05-24 10:21:02 -0700 |
| commit | 667b6249b71c30c20fcd2f312f1665d90348635a (patch) | |
| tree | 72547565f82eafe9b7ac98841ea759b289bf1d21 | |
| parent | 9e61d12bac206e5e70176734604371ac3a6e50fd (diff) | |
| parent | 187b96db5ca79423618dfa29a05c438c34f9e1f0 (diff) | |
Merge tag 'x86-urgent-2020-05-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"Two fixes for x86:
- Unbreak stack dumps for inactive tasks by interpreting the special
first frame left by __switch_to_asm() correctly.
The recent change not to skip the first frame so ORC and frame
unwinder behave in the same way caused all entries to be
unreliable, i.e. prepended with '?'.
- Use cpumask_available() instead of an implicit NULL check of a
cpumask_var_t in mmio trace to prevent a Clang build warning"
* tag 'x86-urgent-2020-05-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/unwind/orc: Fix unwind_get_return_address_ptr() for inactive tasks
x86/mmiotrace: Use cpumask_available() for cpumask_var_t variables
| -rw-r--r-- | arch/x86/kernel/unwind_orc.c | 7 | ||||
| -rw-r--r-- | arch/x86/mm/mmio-mod.c | 4 |
2 files changed, 9 insertions, 2 deletions
diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index fa79e4227d3d..7f969b2d240f 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -320,12 +320,19 @@ EXPORT_SYMBOL_GPL(unwind_get_return_address); unsigned long *unwind_get_return_address_ptr(struct unwind_state *state) { + struct task_struct *task = state->task; + if (unwind_done(state)) return NULL; if (state->regs) return &state->regs->ip; + if (task != current && state->sp == task->thread.sp) { + struct inactive_task_frame *frame = (void *)task->thread.sp; + return &frame->ret_addr; + } + if (state->sp) return (unsigned long *)state->sp - 1; diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c index 109325d77b3e..43fd19b3f118 100644 --- a/arch/x86/mm/mmio-mod.c +++ b/arch/x86/mm/mmio-mod.c @@ -372,7 +372,7 @@ static void enter_uniprocessor(void) int cpu; int err; - if (downed_cpus == NULL && + if (!cpumask_available(downed_cpus) && !alloc_cpumask_var(&downed_cpus, GFP_KERNEL)) { pr_notice("Failed to allocate mask\n"); goto out; @@ -402,7 +402,7 @@ static void leave_uniprocessor(void) int cpu; int err; - if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0) + if (!cpumask_available(downed_cpus) || cpumask_weight(downed_cpus) == 0) return; pr_notice("Re-enabling CPUs...\n"); for_each_cpu(cpu, downed_cpus) { |