diff options
Diffstat (limited to 'Documentation/x86/kernel-stacks')
| -rw-r--r-- | Documentation/x86/kernel-stacks | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/Documentation/x86/kernel-stacks b/Documentation/x86/kernel-stacks index 1b04596caea9..d1bfb0b95ee0 100644 --- a/Documentation/x86/kernel-stacks +++ b/Documentation/x86/kernel-stacks @@ -76,7 +76,7 @@ The currently assigned IST stacks are :- middle of switching stacks. Using IST for NMI events avoids making assumptions about the previous state of the kernel stack. -* ESTACK_DB. DEBUG_STKSZ +* ESTACK_DB. EXCEPTION_STKSZ (PAGE_SIZE). Used for hardware debug interrupts (interrupt 1) and for software debug interrupts (INT3). @@ -86,6 +86,11 @@ The currently assigned IST stacks are :- avoids making assumptions about the previous state of the kernel stack. + To handle nested #DB correctly there exist two instances of DB stacks. On + #DB entry the IST stackpointer for #DB is switched to the second instance + so a nested #DB starts from a clean stack. The nested #DB switches + the IST stackpointer to a guard hole to catch triple nesting. + * ESTACK_MCE. EXCEPTION_STKSZ (PAGE_SIZE). Used for interrupt 18 - Machine Check Exception (#MC). |