Hi Lianbo, Thanks for the reviews > After applying the v5, I still got the following errors: > > crash> gdb bt > #0 <unavailable> in ?? () > #1 0xc0000000000f570c in plpar_hcall_norets_notrace () at > arch/powerpc/platforms/pseries/hvCall.S:111 > #2 0xc000000001004dd8 in cede_processor () at > ./arch/powerpc/include/asm/plpar_wrappers.h:37 > #3 check_and_cede_processor () at drivers/cpuidle/cpuidle-pseries.c:83 > #4 0xc000000001005000 in shared_cede_loop (dev=<optimized out>, > drv=<optimized out>, index=<optimized out>) at > drivers/cpuidle/cpuidle-pseries.c:256 > #5 0xc000000001004498 in cpuidle_enter_state > (dev=dev@entry=0xc0000001ff5910c0, drv=drv@entry=0xc000000002b8f558 > <pseries_idle_driver>, index=index@entry=1) at drivers/cpuidle/cpuidle.c:267 > #6 0xc000000000c0eb4c in cpuidle_enter (drv=0xc000000002b8f558 > <pseries_idle_driver>, dev=0xc0000001ff5910c0, index=<optimized out>) at > drivers/cpuidle/cpuidle.c:388 > #7 0xc0000000001ce2bc in call_cpuidle (drv=<optimized out>, > drv@entry=0xc000000002b8f558 <pseries_idle_driver>, dev=<optimized out>, > dev@entry=0xc0000001ff5910c0, next_state=<optimized out>) at > kernel/sched/idle.c:134 > #8 0xc0000000001d5d68 in cpuidle_idle_call () at kernel/sched/idle.c:215 > #9 0xc0000000001d5f58 in do_idle () at kernel/sched/idle.c:282 > #10 0xc0000000001d6298 in cpu_startup_entry (state=<optimized out>) at > kernel/sched/idle.c:380 > #11 0xc000000000011030 in rest_init () at init/main.c:730 > gdb: page excluded: kernel virtual address: c000000002004c80 type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c000000002004c7c type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c000000002004c78 type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c000000002004c80 type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c000000002004c7c type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c000000002004c78 type: > "gdb_readmem callback" > #12 0xc000000002004c80 in arch_call_rest_init () at init/main.c:827 > gdb: page excluded: kernel virtual address: c0000000020051ec type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c0000000020051e8 type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c0000000020051e4 type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c0000000020051ec type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c0000000020051e8 type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c0000000020051e4 type: > "gdb_readmem callback" > #13 0xc0000000020051ec in start_kernel () at init/main.c:1072 > #14 0xc00000000000e788 in start_here_common () at > arch/powerpc/kernel/head_64.S:1039 > crash> gdb frame > #0 <unavailable> in ?? () > crash> set gdb on > gdb: on > gdb> bt > #0 <unavailable> in ?? () > #1 0xc0000000000f570c in plpar_hcall_norets_notrace () at > arch/powerpc/platforms/pseries/hvCall.S:111 > #2 0xc000000001004dd8 in cede_processor () at > ./arch/powerpc/include/asm/plpar_wrappers.h:37 > #3 check_and_cede_processor () at drivers/cpuidle/cpuidle-pseries.c:83 > #4 0xc000000001005000 in shared_cede_loop (dev=<optimized out>, > drv=<optimized out>, index=<optimized out>) at > drivers/cpuidle/cpuidle-pseries.c:256 > #5 0xc000000001004498 in cpuidle_enter_state > (dev=dev@entry=0xc0000001ff5910c0, drv=drv@entry=0xc000000002b8f558 > <pseries_idle_driver>, index=index@entry=1) at drivers/cpuidle/cpuidle.c:267 > #6 0xc000000000c0eb4c in cpuidle_enter (drv=0xc000000002b8f558 > <pseries_idle_driver>, dev=0xc0000001ff5910c0, index=<optimized out>) at > drivers/cpuidle/cpuidle.c:388 > #7 0xc0000000001ce2bc in call_cpuidle (drv=<optimized out>, > drv@entry=0xc000000002b8f558 <pseries_idle_driver>, dev=<optimized out>, > dev@entry=0xc0000001ff5910c0, next_state=<optimized out>) at > kernel/sched/idle.c:134 > #8 0xc0000000001d5d68 in cpuidle_idle_call () at kernel/sched/idle.c:215 > #9 0xc0000000001d5f58 in do_idle () at kernel/sched/idle.c:282 > #10 0xc0000000001d6298 in cpu_startup_entry (state=<optimized out>) at > kernel/sched/idle.c:380 > #11 0xc000000000011030 in rest_init () at init/main.c:730 > #12 0xc000000002004c80 in arch_call_rest_init () at init/main.c:827 > #13 0xc0000000020051ec in start_kernel () at init/main.c:1072 > #14 0xc00000000000e788 in start_here_common () at > arch/powerpc/kernel/head_64.S:1039 > gdb> info threads > Id Target Id Frame > * 1 CPU 0 plpar_hcall_norets_notrace () at > arch/powerpc/platforms/pseries/hvCall.S:114 > 2 CPU 1 plpar_hcall_norets_notrace () at > arch/powerpc/platforms/pseries/hvCall.S:114 > 3 CPU 2 plpar_hcall_norets_notrace () at > arch/powerpc/platforms/pseries/hvCall.S:114 > 4 CPU 3 plpar_hcall_norets_notrace () at > arch/powerpc/platforms/pseries/hvCall.S:114 > 5 CPU 4 plpar_hcall_norets_notrace () at > arch/powerpc/platforms/pseries/hvCall.S:114 > 6 CPU 5 0xc00000000028b5e8 in crash_setup_regs > (oldregs=<optimized out>, newregs=0xc00000005d3e7958) at > ./arch/powerpc/include/asm/kexec.h:69 > 7 CPU 6 plpar_hcall_norets_notrace () at > arch/powerpc/platforms/pseries/hvCall.S:114 > 8 CPU 7 plpar_hcall_norets_notrace () at > arch/powerpc/platforms/pseries/hvCall.S:114 > gdb: page excluded: kernel virtual address: c000000002004c80 type: > "gdb_readmem_callback" > gdb: page excluded: kernel virtual address: c000000002004c7c type: > "gdb_readmem_callback" > gdb: page excluded: kernel virtual address: c000000002004c78 type: > "gdb_readmem_callback" > gdb: page excluded: kernel virtual address: c000000002004c80 type: > "gdb_readmem_callback" > gdb: page excluded: kernel virtual address: c000000002004c7c type: > "gdb_readmem_callback" > gdb: page excluded: kernel virtual address: c000000002004c78 type: > "gdb_readmem_callback" > gdb: page excluded: kernel virtual address: c0000000020051ec type: > "gdb_readmem_callback" > gdb: page excluded: kernel virtual address: c0000000020051e8 type: > "gdb_readmem_callback" > gdb: page excluded: kernel virtual address: c0000000020051e4 type: > "gdb_readmem_callback" > gdb: page excluded: kernel virtual address: c0000000020051ec type: > "gdb_readmem_callback" > gdb: page excluded: kernel virtual address: c0000000020051e8 type: > "gdb_readmem_callback" > gdb: page excluded: kernel virtual address: c0000000020051e4 type: > "gdb_readmem_callback" > > gdb> thread 1 > [Switching to thread 1 (CPU 0)] > #0 plpar_hcall_norets_notrace () at > arch/powerpc/platforms/pseries/hvCall.S:114 > 114 li r4,0 > gdb> bt > #0 plpar_hcall_norets_notrace () at > arch/powerpc/platforms/pseries/hvCall.S:114 > #1 0xc000000001004dd8 in cede_processor () at > ./arch/powerpc/include/asm/plpar_wrappers.h:37 > #2 check_and_cede_processor () at drivers/cpuidle/cpuidle-pseries.c:83 > #3 0xc000000001005000 in shared_cede_loop (dev=<optimized out>, > drv=<optimized out>, index=<optimized out>) at > drivers/cpuidle/cpuidle-pseries.c:256 > #4 0xc000000001004498 in cpuidle_enter_state > (dev=dev@entry=0xc0000001ff5910c0, drv=drv@entry=0xc000000002b8f558 > <pseries_idle_driver>, index=index@entry=1) at drivers/cpuidle/cpuidle.c:267 > #5 0xc000000000c0eb4c in cpuidle_enter (drv=0xc000000002b8f558 > <pseries_idle_driver>, dev=0xc0000001ff5910c0, index=<optimized out>) at > drivers/cpuidle/cpuidle.c:388 > #6 0xc0000000001ce2bc in call_cpuidle (drv=<optimized out>, > drv@entry=0xc000000002b8f558 <pseries_idle_driver>, dev=<optimized out>, > dev@entry=0xc0000001ff5910c0, next_state=<optimized out>) at > kernel/sched/idle.c:134 > #7 0xc0000000001d5d68 in cpuidle_idle_call () at kernel/sched/idle.c:215 > #8 0xc0000000001d5f58 in do_idle () at kernel/sched/idle.c:282 > #9 0xc0000000001d6298 in cpu_startup_entry (state=<optimized out>) at > kernel/sched/idle.c:380 > #10 0xc000000000011030 in rest_init () at init/main.c:730 > gdb: page excluded: kernel virtual address: c000000002004c80 type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c000000002004c7c type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c000000002004c78 type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c000000002004c80 type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c000000002004c7c type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c000000002004c78 type: > "gdb_readmem callback" > #11 0xc000000002004c80 in arch_call_rest_init () at init/main.c:827 > gdb: page excluded: kernel virtual address: c0000000020051ec type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c0000000020051e8 type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c0000000020051e4 type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c0000000020051ec type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c0000000020051e8 type: > "gdb_readmem callback" > gdb: page excluded: kernel virtual address: c0000000020051e4 type: > "gdb_readmem callback" > #12 0xc0000000020051ec in start_kernel () at init/main.c:1072 > #13 0xc00000000000e788 in start_here_common () at > arch/powerpc/kernel/head_64.S:1039 > gdb> thread 3 > [Switching to thread 3 (CPU 2)] > #0 plpar_hcall_norets_notrace () at > arch/powerpc/platforms/pseries/hvCall.S:114 > 114 li r4,0 > gdb> bt > #0 plpar_hcall_norets_notrace () at > arch/powerpc/platforms/pseries/hvCall.S:114 > #1 0xc000000001004dd8 in cede_processor () at > ./arch/powerpc/include/asm/plpar_wrappers.h:37 > #2 check_and_cede_processor () at drivers/cpuidle/cpuidle-pseries.c:83 > #3 0xc000000001005000 in shared_cede_loop (dev=<optimized out>, > drv=<optimized out>, index=<optimized out>) at > drivers/cpuidle/cpuidle-pseries.c:256 > #4 0xc000000001004498 in cpuidle_enter_state > (dev=dev@entry=0xc0000001ff7910c0, drv=drv@entry=0xc000000002b8f558 > <pseries_idle_driver>, index=index@entry=1) at drivers/cpuidle/cpuidle.c:267 > #5 0xc000000000c0eb4c in cpuidle_enter (drv=0xc000000002b8f558 > <pseries_idle_driver>, dev=0xc0000001ff7910c0, index=<optimized out>) at > drivers/cpuidle/cpuidle.c:388 > #6 0xc0000000001ce2bc in call_cpuidle (drv=<optimized out>, > drv@entry=0xc000000002b8f558 <pseries_idle_driver>, dev=<optimized out>, > dev@entry=0xc0000001ff7910c0, next_state=<optimized out>) at > kernel/sched/idle.c:134 > #7 0xc0000000001d5d68 in cpuidle_idle_call () at kernel/sched/idle.c:215 > #8 0xc0000000001d5f58 in do_idle () at kernel/sched/idle.c:282 > #9 0xc0000000001d6298 in cpu_startup_entry (state=<optimized out>) at > kernel/sched/idle.c:380 > #10 0xc00000000005f048 in start_secondary (unused=<optimized out>) at > arch/powerpc/kernel/smp.c:1680 > #11 0xc00000000000e058 in start_secondary_prolog () at > arch/powerpc/kernel/head_64.S:885 > gdb> > > > Could you please check it again? Or am I missing anything? I did the test > based on upstream kernel 6.7.0-rc7(commit:8735c7c84d1b). I am checking it. Trying to fix the 'page excluded' error. As of now, I found that it happens when gdb is trying to unwind the frames. It tries 'tramp_frame_sniffer' unwinder which causes those errors, afaik it's normal for most unwinders to fail to unwind (gdb tries all unwinders to see which one can unwind the previous frame), will see how to handle this case. > > BTW: I did not see the similar issues after applying the v4 patch set. There was a minor bug in V5, due to gdb thread still set to thread 0 initially. Fixed that one. Thanks, Aditya Gupta > > > Thanks > > Lianbo > > > > > Known Issues: > > ============= > > > > 1. In gdb mode, 'bt' might fail to show backtrace in few vmcores collected > > from older kernels. This is a known issue due to register mismatch, and > > its fix has been merged upstream: > > > > This can also cause some 'invalid kernel virtual address' errors during gdb > > unwinding the stack registers > > > > Commit: https://github.com/torvalds/linux/commit/b684c09f09e7a6af3794d4233ef785819e72db79 > > > > Fixing GDB passthroughs on other architectures > > ============================================== > > > > Much of the work for making gdb passthroughs like 'gdb bt', 'gdb > > thread', 'gdb info locals' etc. has been done by the patches introducing > > 'machdep->get_cpu_reg' and this series fixing some issues in that. > > > > Other architectures should be able to fix these gdb functionalities by > > simply implementing 'machdep->get_cpu_reg (cpu, regno, ...)'. > > > > The reasoning behind that has been explained with a diagram in commit > > description of patch #1 > > > > I will assist with my findings/observations fixing it on ppc64 whenever needed. > > > > Changelog: > > ========== > > > > V5: > > + changes in patch #1: made ppc64_get_cpu_reg static, and remove unreachable > > code > > + changes in patch #3: fixed typo 'ppc64_renum' instead of 'ppc64_regnum', > > remove unneeded if condition > > + changes in patch #5: implement refresh regcache on per thread, instead of all > > threads at once > > > > V4: > > + fix segmentation fault in live debugging (change in patch #1) > > + mention live debugging not supported in cover letter and patch #1 > > + fixed some checkpatch warnings (change in patch #5) > > > > V3: > > + default gdb thread will be the crashing thread, instead of being > > thread '0' > > + synchronise crash cpu and gdb thread context > > + fix bug in gdb_interface, that replaced gdb's output stream, losing > > output in some cases, such as info threads and extra output in info > > variables > > + fix 'info threads' > > > > RFC V2: > > - removed patch implementing 'frame', 'up', 'down' in crash > > - updated the cover letter by removing the mention of those commands other > > than the respective gdb passthrough > > > > Aditya Gupta (5): > > ppc64: correct gdb passthroughs by implementing machdep->get_cpu_reg > > remove 'frame' from prohibited commands list > > synchronise cpu context changes between crash/gdb > > fix gdb_interface: restore gdb's output streams at end of > > gdb_interface > > fix 'info threads' command > > > > crash_target.c | 44 ++++++++++++++++ > > defs.h | 130 +++++++++++++++++++++++++++++++++++++++++++++++- > > gdb-10.2.patch | 110 +++++++++++++++++++++++++++++++++++++++- > > gdb_interface.c | 2 +- > > kernel.c | 47 +++++++++++++++-- > > ppc64.c | 95 +++++++++++++++++++++++++++++++++-- > > task.c | 14 ++++++ > > tools.c | 2 +- > > 8 files changed, 434 insertions(+), 10 deletions(-) > > > -- Crash-utility mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxxxxxx https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/ Contribution Guidelines: https://github.com/crash-utility/crash/wiki
