Commit-ID: df835e7083bee33e98635aca26b39b63ebc6cca7 Gitweb: https://git.kernel.org/tip/df835e7083bee33e98635aca26b39b63ebc6cca7 Author: Thomas Gleixner <[email protected]> AuthorDate: Sun, 14 Apr 2019 17:59:41 +0200 Committer: Borislav Petkov <[email protected]> CommitDate: Wed, 17 Apr 2019 12:34:49 +0200
x86/irq/64: Sanitize the top/bottom confusion 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 <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Sean Christopherson <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Nicolai Stange <[email protected]> Cc: x86-ml <[email protected]> Link: https://lkml.kernel.org/r/[email protected] --- arch/x86/kernel/irq_64.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c index f6dcc8fea5c0..cf200466d5c8 100644 --- a/arch/x86/kernel/irq_64.c +++ b/arch/x86/kernel/irq_64.c @@ -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");
