[PATCH] x86_64: Move int 3 handler to debug stack and allow to increase it.
This
- switches the INT3 handler to run on an IST stack (to cope with
breakpoints set by a kernel debugger on places where the kernel's
%gs base hasn't been set up, yet); the IST stack used is shared with
the INT1 handler's
[AK: this also allows setting a kprobe on the interrupt/exception entry
points]
- allows nesting of INT1/INT3 handlers so that one can, with a kernel
debugger, debug (at least) the user-mode portions of the INT1/INT3
handling; the nesting isn't actively enabled here since a kernel-
debugger-free kernel doesn't need it
Signed-Off-By: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/asm-x86_64/desc.h b/include/asm-x86_64/desc.h
index 3376486..5ce0e34 100644
--- a/include/asm-x86_64/desc.h
+++ b/include/asm-x86_64/desc.h
@@ -114,6 +114,11 @@
_set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, 0);
}
+static inline void set_system_gate_ist(int nr, void *func, unsigned ist)
+{
+ _set_gate(&idt_table[nr], GATE_INTERRUPT, (unsigned long) func, 3, ist);
+}
+
static inline void set_tssldt_descriptor(void *ptr, unsigned long tss, unsigned type,
unsigned size)
{