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x86/irq/64: Sanitize the top/bottom confusion

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On x86, stacks go top to bottom, but the stack overflow check uses it
the other way round, which is just confusing. Clean it up and sanitize
the warning string a bit.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190414160143.961241397@linutronix.de
This commit is contained in:
Thomas Gleixner 2019-04-14 17:59:41 +02:00 committed by Borislav Petkov
parent 4f44b8f0b3
commit df835e7083
1 changed files with 11 additions and 11 deletions
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22
arch/x86/kernel/irq_64.c
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@ -42,7 +42,7 @@ int sysctl_panic_on_stackoverflow;
static inline void stack_overflow_check(struct pt_regs *regs)
{
#ifdef CONFIG_DEBUG_STACKOVERFLOW
#define STACK_TOP_MARGIN 128
#define STACK_MARGIN 128
struct orig_ist *oist;
u64 irq_stack_top, irq_stack_bottom;
u64 estack_top, estack_bottom;
@ -51,25 +51,25 @@ static inline void stack_overflow_check(struct pt_regs *regs)
if (user_mode(regs))
return;
if (regs->sp >= curbase + sizeof(struct pt_regs) + STACK_TOP_MARGIN &&
if (regs->sp >= curbase + sizeof(struct pt_regs) + STACK_MARGIN &&
regs->sp <= curbase + THREAD_SIZE)
return;
irq_stack_bottom = (u64)__this_cpu_read(irq_stack_ptr);
irq_stack_top = irq_stack_bottom - IRQ_STACK_SIZE + STACK_TOP_MARGIN;
if (regs->sp >= irq_stack_top && regs->sp <= irq_stack_bottom)
irq_stack_top = (u64)__this_cpu_read(irq_stack_ptr);
irq_stack_bottom = irq_stack_top - IRQ_STACK_SIZE + STACK_MARGIN;
if (regs->sp >= irq_stack_bottom && regs->sp <= irq_stack_top)
return;
oist = this_cpu_ptr(&orig_ist);
estack_bottom = (u64)oist->ist[DEBUG_STACK];
estack_top = estack_bottom - DEBUG_STKSZ + STACK_TOP_MARGIN;
if (regs->sp >= estack_top && regs->sp <= estack_bottom)
estack_top = (u64)oist->ist[DEBUG_STACK];
estack_bottom = estack_top - DEBUG_STKSZ + STACK_MARGIN;
if (regs->sp >= estack_bottom && regs->sp <= estack_top)
return;
WARN_ONCE(1, "do_IRQ(): %s has overflown the kernel stack (cur:%Lx,sp:%lx,irq stk top-bottom:%Lx-%Lx,exception stk top-bottom:%Lx-%Lx,ip:%pF)\n",
WARN_ONCE(1, "do_IRQ(): %s has overflown the kernel stack (cur:%Lx,sp:%lx, irq stack:%Lx-%Lx, exception stack: %Lx-%Lx, ip:%pF)\n",
current->comm, curbase, regs->sp,
irq_stack_top, irq_stack_bottom,
estack_top, estack_bottom, (void *)regs->ip);
irq_stack_bottom, irq_stack_top,
estack_bottom, estack_top, (void *)regs->ip);
if (sysctl_panic_on_stackoverflow)
panic("low stack detected by irq handler - check messages\n");