Commit 5f8efbb9 authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds

[PATCH] x86_64: Allow nesting of int3 by default for kprobes

This unbreaks recursive kprobes which didn't work anymore
due to an earlier patch which converted the debug entry point
to use an IST.

This also allows nesting of the debug entry point too.
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent aa41eb99
......@@ -43,6 +43,7 @@ int main(void)
ENTRY(irqcount);
ENTRY(cpunumber);
ENTRY(irqstackptr);
ENTRY(data_offset);
BLANK();
#undef ENTRY
#ifdef CONFIG_IA32_EMULATION
......@@ -66,8 +67,6 @@ int main(void)
DEFINE(pbe_orig_address, offsetof(struct pbe, orig_address));
DEFINE(pbe_next, offsetof(struct pbe, next));
BLANK();
#if DEBUG_STKSZ > EXCEPTION_STKSZ
DEFINE(DEBUG_IST, DEBUG_STACK);
#endif
DEFINE(TSS_ist, offsetof(struct tss_struct, ist));
return 0;
}
......@@ -41,6 +41,7 @@
#include <asm/unistd.h>
#include <asm/thread_info.h>
#include <asm/hw_irq.h>
#include <asm/page.h>
.code64
......@@ -674,9 +675,6 @@ ENTRY(spurious_interrupt)
/* error code is on the stack already */
/* handle NMI like exceptions that can happen everywhere */
#ifndef DEBUG_IST
# define DEBUG_IST 0
#endif
.macro paranoidentry sym, ist=0
SAVE_ALL
cld
......@@ -695,11 +693,11 @@ ENTRY(spurious_interrupt)
movq ORIG_RAX(%rsp),%rsi
movq $-1,ORIG_RAX(%rsp)
.if \ist
subq $EXCEPTION_STACK_SIZE, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp)
subq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp)
.endif
call \sym
.if \ist
addq $EXCEPTION_STACK_SIZE, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp)
addq $EXCEPTION_STKSZ, per_cpu__init_tss + TSS_ist + (\ist - 1) * 8(%rbp)
.endif
cli
.endm
......@@ -918,7 +916,7 @@ KPROBE_ENTRY(debug)
INTR_FRAME
pushq $0
CFI_ADJUST_CFA_OFFSET 8
paranoidentry do_debug, DEBUG_IST
paranoidentry do_debug, DEBUG_STACK
jmp paranoid_exit
CFI_ENDPROC
.previous .text
......@@ -976,7 +974,7 @@ KPROBE_ENTRY(int3)
INTR_FRAME
pushq $0
CFI_ADJUST_CFA_OFFSET 8
paranoidentry do_int3, DEBUG_IST
paranoidentry do_int3, DEBUG_STACK
jmp paranoid_exit
CFI_ENDPROC
.previous .text
......
......@@ -26,6 +26,13 @@
#define IRQSTACK_ORDER 2
#define IRQSTACKSIZE (PAGE_SIZE << IRQSTACK_ORDER)
#define STACKFAULT_STACK 1
#define DOUBLEFAULT_STACK 2
#define NMI_STACK 3
#define DEBUG_STACK 4
#define MCE_STACK 5
#define N_EXCEPTION_STACKS 5 /* hw limit: 7 */
#define LARGE_PAGE_MASK (~(LARGE_PAGE_SIZE-1))
#define LARGE_PAGE_SIZE (1UL << PMD_SHIFT)
......
......@@ -273,13 +273,6 @@ struct thread_struct {
#define INIT_MMAP \
{ &init_mm, 0, 0, NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
#define STACKFAULT_STACK 1
#define DOUBLEFAULT_STACK 2
#define NMI_STACK 3
#define DEBUG_STACK 4
#define MCE_STACK 5
#define N_EXCEPTION_STACKS 5 /* hw limit: 7 */
#define start_thread(regs,new_rip,new_rsp) do { \
asm volatile("movl %0,%%fs; movl %0,%%es; movl %0,%%ds": :"r" (0)); \
load_gs_index(0); \
......
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