x86/entry/64: Don't use IST entry for #BP stack

There's nothing IST-worthy about #BP/int3.  We don't allow kprobes
in the small handful of places in the kernel that run at CPL0 with
an invalid stack, and 32-bit kernels have used normal interrupt
gates for #BP forever.

Furthermore, we don't allow kprobes in places that have usergs while
in kernel mode, so "paranoid" is also unnecessary.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
This commit is contained in:
Andy Lutomirski
2015-07-23 15:37:48 -07:00
committed by Thomas Gleixner
parent 06ace26f4e
commit d8ba61ba58
3 changed files with 9 additions and 10 deletions

View File

@@ -160,7 +160,6 @@ static const __initconst struct idt_data early_pf_idts[] = {
*/
static const __initconst struct idt_data dbg_idts[] = {
INTG(X86_TRAP_DB, debug),
INTG(X86_TRAP_BP, int3),
};
#endif
@@ -183,7 +182,6 @@ gate_desc debug_idt_table[IDT_ENTRIES] __page_aligned_bss;
static const __initconst struct idt_data ist_idts[] = {
ISTG(X86_TRAP_DB, debug, DEBUG_STACK),
ISTG(X86_TRAP_NMI, nmi, NMI_STACK),
SISTG(X86_TRAP_BP, int3, DEBUG_STACK),
ISTG(X86_TRAP_DF, double_fault, DOUBLEFAULT_STACK),
#ifdef CONFIG_X86_MCE
ISTG(X86_TRAP_MC, &machine_check, MCE_STACK),