----- "Mika Westerberg" <ext-mika.1.westerberg@xxxxxxxxx> wrote:
> Enhance backtracing code to print out userspace registers in case we
> are at syscall entry. Other architectures supported by crash are
> already doing this.
>
> Signed-off-by: Mika Westerberg <ext-mika.1.westerberg@xxxxxxxxx>
> ---
> I tested this with both unwind tables and framepointers enabled on
> my test vmcores, and also on live system.
Works well on my sample dumpfiles -- queued for the next release.
Thanks,
Dave
> arm.c | 31 ++++++++++++++++++++++++++++++-
> 1 files changed, 30 insertions(+), 1 deletions(-)
>
> diff --git a/arm.c b/arm.c
> index 985f78e..a8a34b9 100644
> --- a/arm.c
> +++ b/arm.c
> @@ -31,6 +31,7 @@ static int arm_verify_symbol(const char *, ulong,
> char);
> static int arm_is_module_addr(ulong);
> static int arm_is_kvaddr(ulong);
> static int arm_in_exception_text(ulong);
> +static int arm_in_ret_from_syscall(ulong);
> static void arm_back_trace(struct bt_info *);
> static void arm_back_trace_cmd(struct bt_info *);
> static ulong arm_processor_speed(void);
> @@ -668,6 +669,16 @@ arm_in_exception_text(ulong pc)
> }
>
> /*
> + * Returns TRUE if given pc points to a return from syscall
> entrypoint.
> + */
> +static int
> +arm_in_ret_from_syscall(ulong pc)
> +{
> + return (pc == symbol_value("ret_fast_syscall") ||
> + pc == symbol_value("ret_slow_syscall"));
> +}
> +
> +/*
> * Unroll the kernel stack using a minimal amount of gdb services.
> */
> static void
> @@ -1188,8 +1199,26 @@ arm_dump_backtrace_entry(struct bt_info *bt,
> int level, ulong from, ulong sp)
> fprintf(fp, " %s\n", buf);
> }
>
> - if (arm_in_exception_text(bt->instptr))
> + if (arm_in_exception_text(bt->instptr)) {
> arm_dump_exception_stack(sp, sp + sizeof(struct arm_pt_regs));
> + } else if (arm_in_ret_from_syscall(from)) {
> + /*
> + * When we are returning from the syscall, here is
> + * what the stack frame looks like:
> + *
> + * SP + 0 {r4, r5}
> + * SP + 8 user pt_regs
> + *
> + * The asm syscall handler pushes fifth and sixth
> + * registers onto the stack before calling the
> + * actual syscall handler.
> + *
> + * So in order to print out the user registers when
> + * the syscall was made, we need to adjust sp for 8.
> + */
> + arm_dump_exception_stack(sp + 8,
> + sp + 8 + sizeof(struct arm_pt_regs));
> + }
>
> if (bt->flags & BT_FULL) {
> if (kt->flags & DWARF_UNWIND) {
> --
> 1.7.3.2
>
> --
> Crash-utility mailing list
> Crash-utility@xxxxxxxxxx
> https://www.redhat.com/mailman/listinfo/crash-utility
--
Crash-utility mailing list
Crash-utility@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/crash-utility
