From: Hirokazu Takata <takata@linux-m32r.org>
This patch updates ptrace.c to support multithread debugging. So far, only
one breakpoint's location was kept by kernel, however, in the multithreaded
application's debug, it is required to kept multi-point breakpoint locations
by kernel.
In this implementation, maximum number of MAX_TRAPS(=10 (by default))
breakpoint's information will be kept in the "debug_trap" member of the
thread_struct for each thread.
* include/asm-m32r/processor.h:
Modify debug_trap struct to keep multipoint breakpoint locations
for multithread debugging.
* arch/m32r/kernel/ptrace.c:
- Update to support multithread debugging.
- Remove unused functions, withdraw_debug_trap_for_signal() and
embed_debug_trap_for_signal().
Signed-off-by: Kei Sakamoto <ksakamot@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/arch/m32r/kernel/ptrace.c | 89 +++++++++++------------------------
25-akpm/include/asm-m32r/processor.h | 6 +-
2 files changed, 34 insertions(+), 61 deletions(-)
diff -puN arch/m32r/kernel/ptrace.c~m32r-update-ptracec-for-multithread arch/m32r/kernel/ptrace.c
--- 25/arch/m32r/kernel/ptrace.c~m32r-update-ptracec-for-multithread Thu Dec 16 15:18:33 2004
+++ 25-akpm/arch/m32r/kernel/ptrace.c Thu Dec 16 15:18:33 2004
@@ -2,7 +2,7 @@
* linux/arch/m32r/kernel/ptrace.c
*
* Copyright (C) 2002 Hirokazu Takata, Takeo Takahashi
- * Copyright (C) 2004 Hirokazu Takata <takata at linux-m32r.org>
+ * Copyright (C) 2004 Hirokazu Takata, Kei Sakamoto
*
* Original x86 implementation:
* By Ross Biro 1/23/92
@@ -450,13 +450,13 @@ register_debug_trap(struct task_struct *
struct debug_trap *p = &child->thread.debug_trap;
unsigned long addr = next_pc & ~3;
- if (p->nr_trap != 0) {
+ if (p->nr_trap == MAX_TRAPS) {
printk("kernel BUG at %s %d: p->nr_trap = %d\n",
__FILE__, __LINE__, p->nr_trap);
return -1;
}
- p->addr = addr;
- p->insn = next_insn;
+ p->addr[p->nr_trap] = addr;
+ p->insn[p->nr_trap] = next_insn;
p->nr_trap++;
if (next_pc & 3) {
*code = (next_insn & 0xffff0000) | 0x10f1;
@@ -473,35 +473,34 @@ register_debug_trap(struct task_struct *
return 0;
}
-int withdraw_debug_trap_for_signal(struct task_struct *child)
-{
- struct debug_trap *p = &child->thread.debug_trap;
- int nr_trap = p->nr_trap;
-
- if (nr_trap) {
- access_process_vm(child, p->addr, &p->insn, sizeof(p->insn), 1);
- p->nr_trap = 0;
- p->addr = 0;
- p->insn = 0;
- }
- return nr_trap;
-}
-
static int
unregister_debug_trap(struct task_struct *child, unsigned long addr,
unsigned long *code)
{
struct debug_trap *p = &child->thread.debug_trap;
+ int i;
- if (p->nr_trap != 1 || p->addr != addr) {
+ /* Search debug trap entry. */
+ for (i = 0; i < p->nr_trap; i++) {
+ if (p->addr[i] == addr)
+ break;
+ }
+ if (i >= p->nr_trap) {
/* The trap may be requested from debugger.
* ptrace should do nothing in this case.
*/
return 0;
}
- *code = p->insn;
- p->insn = 0;
- p->addr = 0;
+
+ /* Recover orignal instruction code. */
+ *code = p->insn[i];
+
+ /* Shift debug trap entries. */
+ while (i < p->nr_trap - 1) {
+ p->insn[i] = p->insn[i + 1];
+ p->addr[i] = p->addr[i + 1];
+ i++;
+ }
p->nr_trap--;
return 1;
}
@@ -510,13 +509,11 @@ static void
unregister_all_debug_traps(struct task_struct *child)
{
struct debug_trap *p = &child->thread.debug_trap;
+ int i;
- if (p->nr_trap) {
- access_process_vm(child, p->addr, &p->insn, sizeof(p->insn), 1);
- p->addr = 0;
- p->insn = 0;
- p->nr_trap = 0;
- }
+ for (i = 0; i < p->nr_trap; i++)
+ access_process_vm(child, p->addr[i], &p->insn[i], sizeof(p->insn[i]), 1);
+ p->nr_trap = 0;
}
static inline void
@@ -576,34 +573,6 @@ embed_debug_trap(struct task_struct *chi
}
void
-embed_debug_trap_for_signal(struct task_struct *child)
-{
- unsigned long next_pc;
- unsigned long pc, insn;
- int ret;
-
- pc = get_stack_long(child, PT_BPC);
- ret = access_process_vm(child, pc&~3, &insn, sizeof(insn), 0);
- if (ret != sizeof(insn)) {
- printk("kernel BUG at %s %d: access_process_vm returns %d\n",
- __FILE__, __LINE__, ret);
- return;
- }
- compute_next_pc(insn, pc, &next_pc, child);
- if (next_pc & 0x80000000) {
- printk("kernel BUG at %s %d: next_pc = 0x%08x\n",
- __FILE__, __LINE__, (int)next_pc);
- return;
- }
- if (embed_debug_trap(child, next_pc)) {
- printk("kernel BUG at %s %d: embed_debug_trap error\n",
- __FILE__, __LINE__);
- return;
- }
- invalidate_cache();
-}
-
-void
withdraw_debug_trap(struct pt_regs *regs)
{
unsigned long addr;
@@ -621,9 +590,12 @@ static void
init_debug_traps(struct task_struct *child)
{
struct debug_trap *p = &child->thread.debug_trap;
+ int i;
p->nr_trap = 0;
- p->addr = 0;
- p->insn = 0;
+ for (i = 0; i < MAX_TRAPS; i++) {
+ p->addr[i] = 0;
+ p->insn[i] = 0;
+ }
}
@@ -855,4 +827,3 @@ void do_syscall_trace(void)
current->exit_code = 0;
}
}
-
diff -puN include/asm-m32r/processor.h~m32r-update-ptracec-for-multithread include/asm-m32r/processor.h
--- 25/include/asm-m32r/processor.h~m32r-update-ptracec-for-multithread Thu Dec 16 15:18:33 2004
+++ 25-akpm/include/asm-m32r/processor.h Thu Dec 16 15:18:33 2004
@@ -70,10 +70,12 @@ typedef struct {
unsigned long seg;
} mm_segment_t;
+#define MAX_TRAPS 10
+
struct debug_trap {
int nr_trap;
- unsigned long addr;
- unsigned long insn;
+ unsigned long addr[MAX_TRAPS];
+ unsigned long insn[MAX_TRAPS];
};
struct thread_struct {
_