Hi,hatayama I've noticed a issue that has not been fixed in this version,gcore unable to parse register correctly in arm64,i found crash-utility is fixed,gcore-command can refer to below change: commit c975008e61121ef8785622c3bc26964da8fe0deb Author: Dave Anderson <anderson(a)redhat.com&gt; Date: Fri Sep 22 14:59:10 2017 -0400 Fix for the ARM64 "bt" command's display of the user mode exception frame at the top of the stack in Linux 4.7 and later kernels. Without the patch, the contents of the user mode exception frame are invalid due to the miscalculation of the starting address of the pt_regs structure on the kernel stack. (anderson(a)redhat.com) gcore patch: commit 837182cc6589095c0d08f71f57953c50ad61cc19 Author: zhaoqianli <zhaoqianli(a)xiaomi.com&gt; Date: Thu Nov 12 19:41:01 2020 +0800 Fix register parsing error caused by miscalculation of the starting address of the pt_regs structure on the kernel stack Signed-off-by: zhaoqianli <zhaoqianli(a)xiaomi.com&gt; diff --git a/libgcore/gcore_arm64.c b/libgcore/gcore_arm64.c index 3257389..c828fee 100644 --- a/libgcore/gcore_arm64.c +++ b/libgcore/gcore_arm64.c @@ -28,7 +28,7 @@ static int gpr_get(struct task_context *target, BZERO(regs, sizeof(*regs)); - readmem(machdep->get_stacktop(target->task) - 16 - SIZE(pt_regs), KVADDR, + readmem(machdep->get_stacktop(target->task) - machdep->machspec->user_eframe_offset, KVADDR, regs, sizeof(struct user_pt_regs), "gpr_get: user_pt_regs", gcore_verbose_error_handle()); @@ -124,7 +124,7 @@ static int compat_gpr_get(struct task_context *target, BZERO(&pt_regs, sizeof(pt_regs)); BZERO(regs, sizeof(*regs)); - readmem(machdep->get_stacktop(target->task) - 16 - SIZE(pt_regs), KVADDR, + readmem(machdep->get_stacktop(target->task) - machdep->machspec->user_eframe_offset, KVADDR, &pt_regs, sizeof(struct pt_regs), "compat_gpr_get: pt_regs", gcore_verbose_error_handle()); Below is my debug message,gdb to loadethe corefile generated by gcore,SP reg is wrong,as a result, the upper-level stack cannot be calculated correctly. ________________________________________ From: d.hatayama(a)fujitsu.com <d.hatayama(a)fujitsu.com&gt; Sent: Thursday, November 12, 2020 9:25 To: crash-utility(a)redhat.com; k-hagio-ab(a)nec.com Cc: Dreyfus, Thirtsa (Mobileye); lijiang(a)redhat.com; 赵乾利 Subject: [External Mail][ANNOUNCE] crash gcore command, version 1.6.0 is released This is the release of crash gcore command, version 1.6.0. This release includes the following 1 new feature and 2 bug fixes. This is tested on the latest kernels on Fedora 33, RHEL8, RHEL7 and RHEL6 on x86_64. Note that ZRAM support is not included in this release because some patch set is still needed in crash utility. Hagio-san, could you update the description of crash gcore command at https://crash-utility.github.io/extensions.html? ChangeLog: - NT_FILE note information is newly supported for tasks in both 64-bit and 32-bit compatible mode: # LANG=C eu-readelf -n core.1.systemd | awk '/FILE$/ {f=1} f == 1 {print $0}' | head -n 10 CORE 12957 FILE 240 files: 564b290de000-564b29112000 00000000 212992 /usr/lib/systemd/systemd 564b29112000-564b291de000 00104000 835584 /usr/lib/systemd/systemd 564b291de000-564b2923d000 00500000 389120 /usr/lib/systemd/systemd 564b2923d000-564b29282000 006d6000 282624 /usr/lib/systemd/systemd 564b29282000-564b29283000 0082f000 4096 /usr/lib/systemd/systemd 7ffbf12c2000-7ffbf134c000 00000000 565248 /etc/selinux/targeted/contexts/files/file_contexts.bin 7ffbf1352000-7ffbf135a000 00000000 32768 /usr/lib64/libnl-3.so.200.26.0 7ffbf135a000-7ffbf1369000 00028000 61440 /usr/lib64/libnl-3.so.200.26.0 (thirtsa.dreyfus(a)intel.com, d.hatayama(a)fujitsu.com) - Fix failure of collecting vDSO mapping if compat vDSO is disabled due to wrongly designed condition for compat tasks that tries to determine vDSO mapping based on VDSO_HIGH_BASE. Without this patch, vDSO mapping page is not collected for tasks running in 32-bit compat mode and thus displaying backtrace by gdb's bt command for the tasks could be incomplete. (d.hatayama(a)fujitsu.com) - Fix failure of invalid structure member offset with the message "gcore: invalid structure member offset: thread_struct_io_bitmap_max" due to change of kernel data structure for io bitmap by the commit <577d5cd7e585> ("x86/ioperm: Move iobitmap data into a struct"). (lijiang(a)redhat.com, d.hatayama(a)fujitsu.com) MD5 CheckSum: # md5sum crash-gcore-command-1.6.0.tar.gz 889843438ad702807d48cccfdee94e89 crash-gcore-command-1.6.0.tar.gz -- Thanks. HATAYAMA, Daisuke #/******本邮件及其附件含有小米公司的保密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制、或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本邮件！ This e-mail and its attachments contain confidential information from XIAOMI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!******/#

Hi,hatayama This condition can be used to judge before or after 4.7,This change is accompanied by the variable stackframe. Before kernel 4.7,user_eframe_offset is "SIZE(pt_regs) + 16",after 4.7 user_eframe_offset is SIZE(pt_regs) ,Anderson's change can compatible with before and after kernel 4.7,so gcore can use "user_eframe_offset" directly. + if (MEMBER_EXISTS("pt_regs", "stackframe")) + machdep->machspec->user_eframe_offset = SIZE(pt_regs); + else + machdep->machspec->user_eframe_offset = SIZE(pt_regs) + 16; + ________________________________________ From: d.hatayama(a)fujitsu.com <d.hatayama(a)fujitsu.com&gt; Sent: Friday, November 13, 2020 14:20 To: 赵乾利 Cc: Dreyfus, Thirtsa (Mobileye); lijiang(a)redhat.com; crash-utility(a)redhat.com; k-hagio-ab(a)nec.com Subject: Re: [External Mail][ANNOUNCE] crash gcore command, version 1.6.0 is released Hi Zhao. Thanks for your prompt response. I see. I'll include fix for this issue into v1.6.1. But I'm waiting for bug reports from other archs a few more weeks. By the way, it looks that the commit c975008e61121ef8785622c3bc26964da8fe0deb of crash utility has the condition MEMBER_EXISTS("pt_regs", "stackframe"). @@ -1376,6 +1377,11 @@ arm64_stackframe_init(void) MEMBER_OFFSET_INIT(elf_prstatus_pr_pid, "elf_prstatus", "pr_pid"); MEMBER_OFFSET_INIT(elf_prstatus_pr_reg, "elf_prstatus", "pr_reg"); + if (MEMBER_EXISTS("pt_regs", "stackframe")) + machdep->machspec->user_eframe_offset = SIZE(pt_regs); + else + machdep->machspec->user_eframe_offset = SIZE(pt_regs) + 16; + machdep->machspec->__exception_text_start = symbol_value("__exception_text_start"); machdep->machspec->__exception_text_end = @ I guess with this patch set, gcore would result in similar issue for kernels before 4.7. Could you improve the patch so that gcore works well for kernls both before and later v4.7 kernel? Thanks. HATAYAMA, Daisuke #/******本邮件及其附件含有小米公司的保密信息，仅限于发送给上面地址中列出的个人或群组。禁止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制、或散发）本邮件中的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本邮件！ This e-mail and its attachments contain confidential information from XIAOMI, which is intended only for the person or entity whose address is listed above. Any use of the information contained herein in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this e-mail in error, please notify the sender by phone or email immediately and delete it!******/#

On Thu, Nov 12, 2020 at 01:29:06PM +0100, 赵乾利 wrote: The above patch was correct, but it looks like the version that actually landed in the crash-gcore git[0] has a small error. The version in the git retains the "- SIZE(pt_regs)" but that should have been be removed as can be seen in the patch above. [0] https://github.com/fujitsu/crash-gcore/commit/19bfb92e50799a82f7ce6179fb3...) So a fix like the below is needed to get valid registers: 8<-------------- From: Vincent Whitchurch <vincent.whitchurch(a)axis.com&gt; Date: Tue, 9 Nov 2021 13:45:42 +0100 Subject: [PATCH] arm64: Fix pt_regs miscalculation The user_eframe_offset includes the SIZE(pt_regs) so that should have been removed in commit 19bfb92e50799a82f7ce6179fb35ccd82061bafd ("arm64: Fix miscalculation of the starting address...") but that removal appears to have got lost. Signed-off-by: Vincent Whitchurch <vincent.whitchurch(a)axis.com&gt; --- src/libgcore/gcore_arm64.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/libgcore/gcore_arm64.c b/src/libgcore/gcore_arm64.c index 678da8d..da9c647 100644 --- a/src/libgcore/gcore_arm64.c +++ b/src/libgcore/gcore_arm64.c @@ -29,7 +29,7 @@ static int gpr_get(struct task_context *target, BZERO(regs, sizeof(*regs)); readmem(machdep->get_stacktop(target->task) - - machdep->machspec->user_eframe_offset - SIZE(pt_regs), KVADDR, + machdep->machspec->user_eframe_offset, KVADDR, regs, sizeof(struct user_pt_regs), "gpr_get: user_pt_regs", gcore_verbose_error_handle()); @@ -126,7 +126,7 @@ static int compat_gpr_get(struct task_context *target, BZERO(regs, sizeof(*regs)); readmem(machdep->get_stacktop(target->task) - - machdep->machspec->user_eframe_offset - SIZE(pt_regs), KVADDR, + machdep->machspec->user_eframe_offset, KVADDR, &pt_regs, sizeof(struct pt_regs), "compat_gpr_get: pt_regs", gcore_verbose_error_handle()); -- 2.28.0