Currently when unwinding starts from pt_regs or encounters pt_regs along
the way unwinder tries to yield 2 unwinding entries:
1. (reliable) ip1: pt_regs->psw.addr, sp1: regs->gprs[15]
2. (non-reliable) ip2: sp1->gprs[8] (r14), sp2: regs->gprs[15]
In case of kretprobes those are identical and serves no other purpose
than causing confusion over duplicated entries and cause kprobes tests
to fail. So, skip a duplicate non-reliable entry in this case.
With that kretprobes and unwinder implementation now comply with
ARCH_CORRECT_STACKTRACE_ON_KRETPROBE.
Reviewed-by: Tobias Huschle <huschle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
select ALTERNATE_USER_ADDRESS_SPACE
select ARCH_32BIT_USTAT_F_TINODE
select ARCH_BINFMT_ELF_STATE
+ select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM
select ARCH_ENABLE_MEMORY_HOTREMOVE
select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
ip = READ_ONCE_NOCHECK(sf->gprs[8]);
reliable = false;
regs = NULL;
- if (!__kernel_text_address(ip)) {
- /* skip bogus %r14 */
+ /* skip bogus %r14 or if is the same as regs->psw.addr */
+ if (!__kernel_text_address(ip) || state->ip == unwind_recover_ret_addr(state, ip)) {
state->regs = NULL;
return unwind_next_frame(state);
}