Hi lianbo, On Fri, Jun 20, 2025 at 7:06 PM lijiang <liji...@redhat.com> wrote: > > On Thu, Jun 19, 2025 at 7:16 PM Tao Liu <l...@redhat.com> wrote: >> >> Hi lianbo, >> >> On Thu, Jun 19, 2025 at 2:49 PM lijiang <liji...@redhat.com> wrote: >> > >> > For ppc64 machine, I noticed that the gdb bt may not work as expected, for >> > example: >> > >> > crash> set 2 >> > PID: 2 >> > COMMAND: "kthreadd" >> > TASK: c000000004797f80 [THREAD_INFO: c000000004797f80] >> > CPU: 0 >> > STATE: TASK_INTERRUPTIBLE >> > crash> bt >> > PID: 2 TASK: c000000004797f80 CPU: 0 COMMAND: "kthreadd" >> > #0 [c00000000484fbc0] _end at c00000000484fd70 (unreliable) >> > #1 [c00000000484fd70] __switch_to at c00000000001fabc >> > #2 [c00000000484fdd0] __schedule at c0000000011ca9dc >> > #3 [c00000000484feb0] schedule at c0000000011caeb0 >> > #4 [c00000000484ff20] kthreadd at c0000000001af6c4 >> > #5 [c00000000484ffe0] start_kernel_thread at c00000000000ded8 >> > crash> gdb bt >> > #0 0xc00000000484fd70 in ?? () >> > gdb: gdb request failed: bt >> > crash> >> > crash> sys|grep RELEASE >> > RELEASE: 6.12.0 >> > >> > Is that expected behavior?(I do not remember if I mentioned the similar >> > issue in the previous patch review.) >> > >> This is a ppc bug which we encountered some time ago. See [1], in >> short, we cannot determine ABI_V2/V1 correctly, a ABI_V2 kernel might >> running a ABI_V1 program, see [2]. But it has no relation to gdb bt. >> > > Can you also add it to the patch log? At least we can mark it as a known > issue, and it's > easy to recall this case in the future.
Sure, will do it in v4 Thanks, Tao Liu > > Thanks > Lianbo > >> >> [1]: >> https://www.mail-archive.com/devel@lists.crash-utility.osci.io/msg01124.html >> [2]: >> https://www.mail-archive.com/devel@lists.crash-utility.osci.io/msg01139.html >> >> > I have no more comments for other changes, just three issues(see another >> > two comments). >> >> Thanks, >> Tao Liu >> >> > >> > Thanks >> > Lianbo >> > >> > On Tue, Jun 3, 2025 at 1:18 PM <devel-requ...@lists.crash-utility.osci.io> >> > wrote: >> >> >> >> Date: Tue, 3 Jun 2025 17:11:38 +1200 >> >> From: Tao Liu <l...@redhat.com> >> >> Subject: [Crash-utility] [PATCH v3 5/5] ppc64: Add gdb multi-stack >> >> unwind support >> >> To: devel@lists.crash-utility.osci.io >> >> Cc: Alexey Makhalov <alexey.makha...@broadcom.com> >> >> Message-ID: <20250603051138.59896-6-l...@redhat.com> >> >> Content-Type: text/plain; charset="US-ASCII"; x-default=true >> >> >> >> Co-developed-by: Alexey Makhalov <alexey.makha...@broadcom.com> >> >> Co-developed-by: Tao Liu <l...@redhat.com> >> >> Signed-off-by: Tao Liu <l...@redhat.com> >> >> --- >> >> ppc64.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++----- >> >> 1 file changed, 64 insertions(+), 6 deletions(-) >> >> >> >> diff --git a/ppc64.c b/ppc64.c >> >> index 532eb3f..d1a5067 100644 >> >> --- a/ppc64.c >> >> +++ b/ppc64.c >> >> @@ -2053,6 +2053,7 @@ ppc64_back_trace_cmd(struct bt_info *bt) >> >> char buf[BUFSIZE]; >> >> struct gnu_request *req; >> >> extern void print_stack_text_syms(struct bt_info *, ulong, ulong); >> >> + extra_stacks_idx = 0; >> >> >> >> bt->flags |= BT_EXCEPTION_FRAME; >> >> >> >> @@ -2071,6 +2072,29 @@ ppc64_back_trace_cmd(struct bt_info *bt) >> >> req->pc = bt->instptr; >> >> req->sp = bt->stkptr; >> >> >> >> + if (is_task_active(bt->task)) { >> >> + if (!extra_stacks_regs[extra_stacks_idx]) { >> >> + extra_stacks_regs[extra_stacks_idx] = >> >> + (struct user_regs_bitmap_struct *) >> >> + malloc(sizeof(struct >> >> user_regs_bitmap_struct)); >> >> + } >> >> + memset(extra_stacks_regs[extra_stacks_idx], 0, >> >> + sizeof(struct user_regs_bitmap_struct)); >> >> + extra_stacks_regs[extra_stacks_idx]->ur.nip = req->pc; >> >> + extra_stacks_regs[extra_stacks_idx]->ur.gpr[1] = req->sp; >> >> + SET_BIT(extra_stacks_regs[extra_stacks_idx]->bitmap, >> >> + REG_SEQ(ppc64_pt_regs, nip)); >> >> + SET_BIT(extra_stacks_regs[extra_stacks_idx]->bitmap, >> >> + REG_SEQ(ppc64_pt_regs, gpr[0]) + 1); >> >> + if (!bt->machdep || >> >> + (extra_stacks_regs[extra_stacks_idx]->ur.gpr[1] != >> >> + ((struct user_regs_bitmap_struct >> >> *)(bt->machdep))->ur.gpr[1] && >> >> + extra_stacks_regs[extra_stacks_idx]->ur.nip != >> >> + ((struct user_regs_bitmap_struct >> >> *)(bt->machdep))->ur.nip)) { >> >> + gdb_add_substack (extra_stacks_idx++); >> >> + } >> >> + } >> >> + >> >> if (bt->flags & >> >> (BT_TEXT_SYMBOLS|BT_TEXT_SYMBOLS_PRINT|BT_TEXT_SYMBOLS_NOPRINT)) { >> >> if (!INSTACK(req->sp, bt)) >> >> @@ -2512,6 +2536,28 @@ ppc64_print_eframe(char *efrm_str, struct >> >> ppc64_pt_regs *regs, >> >> fprintf(fp, " %s [%lx] exception frame:\n", efrm_str, regs->trap); >> >> ppc64_print_regs(regs); >> >> ppc64_print_nip_lr(regs, 1); >> >> + >> >> + if (!((regs->msr >> MSR_PR_LG) & 0x1) && >> >> + !(bt->flags & BT_EFRAME_SEARCH)) { >> >> + if (!extra_stacks_regs[extra_stacks_idx]) { >> >> + extra_stacks_regs[extra_stacks_idx] = >> >> + (struct user_regs_bitmap_struct *) >> >> + malloc(sizeof(struct >> >> user_regs_bitmap_struct)); >> >> + } >> >> + memset(extra_stacks_regs[extra_stacks_idx], 0, >> >> + sizeof(struct user_regs_bitmap_struct)); >> >> + memcpy(&extra_stacks_regs[extra_stacks_idx]->ur, regs, >> >> + sizeof(struct ppc64_pt_regs)); >> >> + for (int i = 0; i < sizeof(struct >> >> ppc64_pt_regs)/sizeof(ulong); i++) >> >> + >> >> SET_BIT(extra_stacks_regs[extra_stacks_idx]->bitmap, i); >> >> + if (!bt->machdep || >> >> + (extra_stacks_regs[extra_stacks_idx]->ur.gpr[1] != >> >> + ((struct user_regs_bitmap_struct >> >> *)(bt->machdep))->ur.gpr[1] && >> >> + extra_stacks_regs[extra_stacks_idx]->ur.nip != >> >> + ((struct user_regs_bitmap_struct >> >> *)(bt->machdep))->ur.nip)) { >> >> + gdb_add_substack (extra_stacks_idx++); >> >> + } >> >> + } >> >> } >> >> >> >> static int >> >> @@ -2552,6 +2598,12 @@ ppc64_get_current_task_reg(int regno, const char >> >> *name, int size, >> >> tc = CURRENT_CONTEXT(); >> >> if (!tc) >> >> return FALSE; >> >> + >> >> + if (sid && sid <= extra_stacks_idx) { >> >> + ur_bitmap = extra_stacks_regs[sid - 1]; >> >> + goto get_sub; >> >> + } >> >> + >> >> BZERO(&bt_setup, sizeof(struct bt_info)); >> >> clone_bt_info(&bt_setup, &bt_info, tc); >> >> fill_stackbuf(&bt_info); >> >> @@ -2570,39 +2622,45 @@ ppc64_get_current_task_reg(int regno, const char >> >> *name, int size, >> >> goto get_all; >> >> } >> >> >> >> +get_sub: >> >> switch (regno) { >> >> case PPC64_R0_REGNUM ... PPC64_R31_REGNUM: >> >> if (!NUM_IN_BITMAP(ur_bitmap->bitmap, >> >> REG_SEQ(ppc64_pt_regs, gpr[0]) + regno - >> >> PPC64_R0_REGNUM)) { >> >> - FREEBUF(ur_bitmap); >> >> + if (!sid) >> >> + FREEBUF(ur_bitmap); >> >> return FALSE; >> >> } >> >> break; >> >> case PPC64_PC_REGNUM: >> >> if (!NUM_IN_BITMAP(ur_bitmap->bitmap, >> >> REG_SEQ(ppc64_pt_regs, nip))) { >> >> - FREEBUF(ur_bitmap); >> >> + if (!sid) >> >> + FREEBUF(ur_bitmap); >> >> return FALSE; >> >> } >> >> break; >> >> case PPC64_MSR_REGNUM: >> >> if (!NUM_IN_BITMAP(ur_bitmap->bitmap, >> >> REG_SEQ(ppc64_pt_regs, msr))) { >> >> - FREEBUF(ur_bitmap); >> >> + if (!sid) >> >> + FREEBUF(ur_bitmap); >> >> return FALSE; >> >> } >> >> break; >> >> case PPC64_LR_REGNUM: >> >> if (!NUM_IN_BITMAP(ur_bitmap->bitmap, >> >> REG_SEQ(ppc64_pt_regs, link))) { >> >> - FREEBUF(ur_bitmap); >> >> + if (!sid) >> >> + FREEBUF(ur_bitmap); >> >> return FALSE; >> >> } >> >> break; >> >> case PPC64_CTR_REGNUM: >> >> if (!NUM_IN_BITMAP(ur_bitmap->bitmap, >> >> REG_SEQ(ppc64_pt_regs, ctr))) { >> >> - FREEBUF(ur_bitmap); >> >> + if (!sid) >> >> + FREEBUF(ur_bitmap); >> >> return FALSE; >> >> } >> >> break; >> >> @@ -2645,7 +2703,7 @@ get_all: >> >> ret = TRUE; >> >> break; >> >> } >> >> - if (bt_info.need_free) { >> >> + if (!sid && bt_info.need_free) { >> >> FREEBUF(ur_bitmap); >> >> bt_info.need_free = FALSE; >> >> } >> >> -- >> >> 2.47.0 >> > >> > -- >> -- Crash-utility mailing list -- devel@lists.crash-utility.osci.io To unsubscribe send an email to devel-le...@lists.crash-utility.osci.io https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/ Contribution Guidelines: https://github.com/crash-utility/crash/wiki
