diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index 20a5b3689463c6df5d26b98fcfcb2f43fca5b851..dd74fe7273b120643bf2f4a7563295afde009233 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -86,9 +86,15 @@ void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
gdb_regs[GDB_DS] = regs->ds;
gdb_regs[GDB_ES] = regs->es;
gdb_regs[GDB_CS] = regs->cs;
- gdb_regs[GDB_SS] = __KERNEL_DS;
gdb_regs[GDB_FS] = 0xFFFF;
gdb_regs[GDB_GS] = 0xFFFF;
+ if (user_mode_vm(regs)) {
+ gdb_regs[GDB_SS] = regs->ss;
+ gdb_regs[GDB_SP] = regs->sp;
+ } else {
+ gdb_regs[GDB_SS] = __KERNEL_DS;
+ gdb_regs[GDB_SP] = kernel_stack_pointer(regs);
+ }
#else
gdb_regs[GDB_R8] = regs->r8;
gdb_regs[GDB_R9] = regs->r9;
@@ -101,8 +107,8 @@ void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
gdb_regs32[GDB_PS] = regs->flags;
gdb_regs32[GDB_CS] = regs->cs;
gdb_regs32[GDB_SS] = regs->ss;
-#endif
gdb_regs[GDB_SP] = kernel_stack_pointer(regs);
+#endif
}
/**
@@ -220,8 +226,7 @@ static void kgdb_correct_hw_break(void)
dr7 |= ((breakinfo[breakno].len << 2) |
breakinfo[breakno].type) <<
((breakno << 2) + 16);
- if (breakno >= 0 && breakno <= 3)
- set_debugreg(breakinfo[breakno].addr, breakno);
+ set_debugreg(breakinfo[breakno].addr, breakno);
} else {
if ((dr7 & breakbit) && !breakinfo[breakno].enabled) {
@@ -395,7 +400,6 @@ int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
/* set the trace bit if we're stepping */
if (remcomInBuffer[0] == 's') {
linux_regs->flags |= X86_EFLAGS_TF;
- kgdb_single_step = 1;
atomic_set(&kgdb_cpu_doing_single_step,
raw_smp_processor_id());
}
diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c
index e4ff50b95a5ee8c5f834ab17f4834795108eaa8f..fcb6ec1af173dfe22e3130ef6016f348c3f24858 100644
--- a/drivers/misc/kgdbts.c
+++ b/drivers/misc/kgdbts.c
@@ -712,6 +712,12 @@ static int run_simple_test(int is_get_char, int chr)
/* End of packet == #XX so look for the '#' */
if (put_buf_cnt > 3 && put_buf[put_buf_cnt - 3] == '#') {
+ if (put_buf_cnt >= BUFMAX) {
+ eprintk("kgdbts: ERROR: put buffer overflow on"
+ " '%s' line %i\n", ts.name, ts.idx);
+ put_buf_cnt = 0;
+ return 0;
+ }
put_buf[put_buf_cnt] = '\0';
v2printk("put%i: %s\n", ts.idx, put_buf);
/* Trigger check here */
@@ -885,16 +891,16 @@ static void kgdbts_run_tests(void)
int nmi_sleep = 0;
int i;
- ptr = strstr(config, "F");
+ ptr = strchr(config, 'F');
if (ptr)
fork_test = simple_strtol(ptr + 1, NULL, 10);
- ptr = strstr(config, "S");
+ ptr = strchr(config, 'S');
if (ptr)
do_sys_open_test = simple_strtol(ptr + 1, NULL, 10);
- ptr = strstr(config, "N");
+ ptr = strchr(config, 'N');
if (ptr)
nmi_sleep = simple_strtol(ptr+1, NULL, 10);
- ptr = strstr(config, "I");
+ ptr = strchr(config, 'I');
if (ptr)
sstep_test = simple_strtol(ptr+1, NULL, 10);
diff --git a/kernel/kgdb.c b/kernel/kgdb.c
index 7d70146340224b501c2c77dec5fdc0a40bb1820a..2eb517e2351462bd263d8976cf3d2108ecfeebc2 100644
--- a/kernel/kgdb.c
+++ b/kernel/kgdb.c
@@ -129,6 +129,7 @@ struct task_struct *kgdb_usethread;
struct task_struct *kgdb_contthread;
int kgdb_single_step;
+pid_t kgdb_sstep_pid;
/* Our I/O buffers. */
static char remcom_in_buffer[BUFMAX];
@@ -541,12 +542,17 @@ static struct task_struct *getthread(struct pt_regs *regs, int tid)
*/
if (tid == 0 || tid == -1)
tid = -atomic_read(&kgdb_active) - 2;
- if (tid < 0) {
+ if (tid < -1 && tid > -NR_CPUS - 2) {
if (kgdb_info[-tid - 2].task)
return kgdb_info[-tid - 2].task;
else
return idle_task(-tid - 2);
}
+ if (tid <= 0) {
+ printk(KERN_ERR "KGDB: Internal thread select error\n");
+ dump_stack();
+ return NULL;
+ }
/*
* find_task_by_pid_ns() does not take the tasklist lock anymore
@@ -619,7 +625,8 @@ static void kgdb_flush_swbreak_addr(unsigned long addr)
static int kgdb_activate_sw_breakpoints(void)
{
unsigned long addr;
- int error = 0;
+ int error;
+ int ret = 0;
int i;
for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
@@ -629,13 +636,16 @@ static int kgdb_activate_sw_breakpoints(void)
addr = kgdb_break[i].bpt_addr;
error = kgdb_arch_set_breakpoint(addr,
kgdb_break[i].saved_instr);
- if (error)
- return error;
+ if (error) {
+ ret = error;
+ printk(KERN_INFO "KGDB: BP install failed: %lx", addr);
+ continue;
+ }
kgdb_flush_swbreak_addr(addr);
kgdb_break[i].state = BP_ACTIVE;
}
- return 0;
+ return ret;
}
static int kgdb_set_sw_break(unsigned long addr)
@@ -682,7 +692,8 @@ static int kgdb_set_sw_break(unsigned long addr)
static int kgdb_deactivate_sw_breakpoints(void)
{
unsigned long addr;
- int error = 0;
+ int error;
+ int ret = 0;
int i;
for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
@@ -691,13 +702,15 @@ static int kgdb_deactivate_sw_breakpoints(void)
addr = kgdb_break[i].bpt_addr;
error = kgdb_arch_remove_breakpoint(addr,
kgdb_break[i].saved_instr);
- if (error)
- return error;
+ if (error) {
+ printk(KERN_INFO "KGDB: BP remove failed: %lx\n", addr);
+ ret = error;
+ }
kgdb_flush_swbreak_addr(addr);
kgdb_break[i].state = BP_SET;
}
- return 0;
+ return ret;
}
static int kgdb_remove_sw_break(unsigned long addr)
@@ -1204,8 +1217,10 @@ static int gdb_cmd_exception_pass(struct kgdb_state *ks)
return 1;
} else {
- error_packet(remcom_out_buffer, -EINVAL);
- return 0;
+ kgdb_msg_write("KGDB only knows signal 9 (pass)"
+ " and 15 (pass and disconnect)\n"
+ "Executing a continue without signal passing\n", 0);
+ remcom_in_buffer[0] = 'c';
}
/* Indicate fall through */
@@ -1395,6 +1410,7 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
struct kgdb_state kgdb_var;
struct kgdb_state *ks = &kgdb_var;
unsigned long flags;
+ int sstep_tries = 100;
int error = 0;
int i, cpu;
@@ -1425,13 +1441,14 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
cpu_relax();
/*
- * Do not start the debugger connection on this CPU if the last
- * instance of the exception handler wanted to come into the
- * debugger on a different CPU via a single step
+ * For single stepping, try to only enter on the processor
+ * that was single stepping. To gaurd against a deadlock, the
+ * kernel will only try for the value of sstep_tries before
+ * giving up and continuing on.
*/
if (atomic_read(&kgdb_cpu_doing_single_step) != -1 &&
- atomic_read(&kgdb_cpu_doing_single_step) != cpu) {
-
+ (kgdb_info[cpu].task &&
+ kgdb_info[cpu].task->pid != kgdb_sstep_pid) && --sstep_tries) {
atomic_set(&kgdb_active, -1);
touch_softlockup_watchdog();
clocksource_touch_watchdog();
@@ -1524,6 +1541,13 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
}
kgdb_restore:
+ if (atomic_read(&kgdb_cpu_doing_single_step) != -1) {
+ int sstep_cpu = atomic_read(&kgdb_cpu_doing_single_step);
+ if (kgdb_info[sstep_cpu].task)
+ kgdb_sstep_pid = kgdb_info[sstep_cpu].task->pid;
+ else
+ kgdb_sstep_pid = 0;
+ }
/* Free kgdb_active */
atomic_set(&kgdb_active, -1);
touch_softlockup_watchdog();