Dumping registers from other sleeping tasks in KGDB was totally failing for me. All registers were reported as 0.
It looks as if the code was looking at at "task_pt_regs(task)" for the sleeping task and they were all 0. I'm not exactly sure why this structure was used and why it wasn't filled in. There is a more reliable place to look for all of the important registers for a sleeping task: the task_thread_info. This is the same place that is referred to when doing a dump of all sleeping task stacks (kdb_show_stack() -> show_stack() -> dump_backtrace() -> unwind_backtrace() -> thread_saved_sp()). Let's use the more reliable place for all registers that are saved there. We'll fall back to the task_pt_regs() for registers that we don't have. Signed-off-by: Doug Anderson <[email protected]> --- arch/arm/kernel/kgdb.c | 33 ++++++++++++++++++++++----------- 1 file changed, 22 insertions(+), 11 deletions(-) diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c index 07db2f8..bab69db 100644 --- a/arch/arm/kernel/kgdb.c +++ b/arch/arm/kernel/kgdb.c @@ -75,6 +75,7 @@ int dbg_set_reg(int regno, void *mem, struct pt_regs *regs) void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task) { + struct thread_info *ti; struct pt_regs *thread_regs; int regno; @@ -86,24 +87,34 @@ sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task) for (regno = 0; regno < GDB_MAX_REGS; regno++) gdb_regs[regno] = 0; - /* Otherwise, we have only some registers from switch_to() */ + /* + * Try to get as much as we can from the thread_info since the + * pt_regs structure doesn't seem right in most cases. + */ + ti = task_thread_info(task); + gdb_regs[_R4] = ti->cpu_context.r4; + gdb_regs[_R5] = ti->cpu_context.r5; + gdb_regs[_R6] = ti->cpu_context.r6; + gdb_regs[_R7] = ti->cpu_context.r7; + gdb_regs[_R8] = ti->cpu_context.r8; + gdb_regs[_R9] = ti->cpu_context.r9; + gdb_regs[_R10] = ti->cpu_context.sl; + gdb_regs[_FP] = ti->cpu_context.fp; + gdb_regs[_SPT] = ti->cpu_context.sp; + gdb_regs[_PC] = ti->cpu_context.pc; + + /* + * task_thread_info() doesn't store callee-saved registers so we'll + * give task_pt_regs() a shot here. I've never actually seen that be + * valid, though + */ thread_regs = task_pt_regs(task); gdb_regs[_R0] = thread_regs->ARM_r0; gdb_regs[_R1] = thread_regs->ARM_r1; gdb_regs[_R2] = thread_regs->ARM_r2; gdb_regs[_R3] = thread_regs->ARM_r3; - gdb_regs[_R4] = thread_regs->ARM_r4; - gdb_regs[_R5] = thread_regs->ARM_r5; - gdb_regs[_R6] = thread_regs->ARM_r6; - gdb_regs[_R7] = thread_regs->ARM_r7; - gdb_regs[_R8] = thread_regs->ARM_r8; - gdb_regs[_R9] = thread_regs->ARM_r9; - gdb_regs[_R10] = thread_regs->ARM_r10; - gdb_regs[_FP] = thread_regs->ARM_fp; gdb_regs[_IP] = thread_regs->ARM_ip; - gdb_regs[_SPT] = thread_regs->ARM_sp; gdb_regs[_LR] = thread_regs->ARM_lr; - gdb_regs[_PC] = thread_regs->ARM_pc; gdb_regs[_CPSR] = thread_regs->ARM_cpsr; } -- 2.2.0.rc0.207.ga3a616c -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
