On Sun, Mar 31, 2019 at 11:40:24PM +0200, Thomas Gleixner wrote: > The defines for the exception stack (IST) array in the TSS are using the > SDM convention IST1 - IST7. That causes all sorts of code to subtract 1 for > array indices related to IST. That's confusing at best and does not provide > any value. > > Make the indices zero based and fixup the usage sites. The only code which > needs to adjust the 0 based index is the interrupt descriptor setup which > needs to add 1 now. > > Signed-off-by: Thomas Gleixner <[email protected]> > --- > Documentation/x86/kernel-stacks | 8 ++++---- > arch/x86/entry/entry_64.S | 4 ++-- > arch/x86/include/asm/page_64_types.h | 13 ++++++++----- > arch/x86/kernel/cpu/common.c | 4 ++-- > arch/x86/kernel/dumpstack_64.c | 14 +++++++------- > arch/x86/kernel/idt.c | 15 +++++++++------ > 6 files changed, 32 insertions(+), 26 deletions(-)
With the below hunk added: Reviewed-by: Borislav Petkov <[email protected]> --- diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 667f1da36208..1e340adf65e8 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -793,7 +793,7 @@ no_context(struct pt_regs *regs, unsigned long error_code, if (is_vmalloc_addr((void *)address) && (((unsigned long)tsk->stack - 1 - address < PAGE_SIZE) || address - ((unsigned long)tsk->stack + THREAD_SIZE) < PAGE_SIZE)) { - unsigned long stack = this_cpu_read(orig_ist.ist[DOUBLEFAULT_STACK]) - sizeof(void *); + unsigned long stack = this_cpu_read(orig_ist.ist[DOUBLEFAULT_IST]) - sizeof(void *); /* * We're likely to be running with very little stack space * left. It's plausible that we'd hit this condition but -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.
