Bug 253881
| Summary: | /usr/bin/lldb: Unable to backtrace a core dump | ||||||||
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| Product: | Base System | Reporter: | Dmitri Goutnik <dmgk> | ||||||
| Component: | bin | Assignee: | Dimitry Andric <dim> | ||||||
| Status: | Closed FIXED | ||||||||
| Severity: | Affects Only Me | CC: | dim, emaste, ota | ||||||
| Priority: | --- | ||||||||
| Version: | CURRENT | ||||||||
| Hardware: | amd64 | ||||||||
| OS: | Any | ||||||||
| Attachments: |
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Description
Dmitri Goutnik
2021-02-26 21:56:03 UTC
Interesting, this works just fine for me on 14.0-CURRENT #0 main-n245108-1bf86687c2eb (as of 2021-02-26): % lldb a.out -c a.out.core (lldb) target create "a.out" --core "a.out.core" Core file '/share/dim/bugs/bug253881/a.out.core' (x86_64) was loaded. (lldb) bt This version of LLDB has no plugin for the mipsassem language. Inspection of frame variables will be limited. * thread #1, name = 'a.out', stop reason = signal SIGABRT * frame #0: 0x000000080038437a libc.so.7`__sys_thr_kill at thr_kill.S:4 frame #1: 0x00000008002f90f4 libc.so.7`__raise(s=6) at raise.c:52:10 frame #2: 0x0000000000201892 a.out`main at testcase.c:6:5 frame #3: 0x0000000000201690 a.out`_start(ap=<unavailable>, cleanup=<unavailable>) at crt1_c.c:75:7 Is it possible for you to debug the lldb.core file with, say, gdb? :) This lldb's stack trace looks similar to one I just filed - https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=253881 For my case, I don't use core file and lldb crashes with "run" command. My report contains trace from gdb. *** Bug 257829 has been marked as a duplicate of this bug. *** Created attachment 227227 [details] Fix lldb sometimes throwing a 'unhandled Error' I've identified the problem, which only occurs when LLVM assertions are off (this is default on -STABLE and -RELEASE branches, but it can be turned off on -CURRENT using WITHOUT_LLVM_ASSERTSIONS too), and submitted a fix to upstream as: https://reviews.llvm.org/D108088 Meanwhile, can you please try the attached patch on a recent FreeBSD 14.0 or 13.0 source tree, and see if it resolves the problem for you? (This probably won't apply cleanly on a stable/12 tree.) (In reply to Dimitry Andric from comment #4) Hunk #1 failed against releng/13.0 unfortunately. Do you want me to try stable/13? I will need to setup stable/13, though. Created attachment 227244 [details] Fix lldb 11 sometimes throwing a 'unhandled Error' (In reply to ota from comment #5) I added this other patch that should apply cleanly on top of the lldb version (11) that is in releng/13.0. Can you please try that one instead? (In reply to Dimitry Andric from comment #6) The lldb 11 patch applied fine. I confirmed lldb stopped crashing for the other PR test program with this patch. A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=c1a540709a83f810aa47380b946552ab20020374 commit c1a540709a83f810aa47380b946552ab20020374 Author: Dimitry Andric <dim@FreeBSD.org> AuthorDate: 2021-08-16 16:56:41 +0000 Commit: Dimitry Andric <dim@FreeBSD.org> CommitDate: 2021-08-16 16:57:24 +0000 Apply upstream lldb fix for unhandled Error causing abort Merge commit 5033f0793fe6 from llvm git (by Dimitry Andric): [lldb] Avoid unhandled Error in TypeSystemMap::GetTypeSystemForLanguage When assertions are turned off, the `llvm::Error` value created at the start of this function is overwritten using the move-assignment operator, but the success value is never checked. Whenever a TypeSystem cannot be found or created, this can lead to lldb core dumping with: Program aborted due to an unhandled Error: Error value was Success. (Note: Success values must still be checked prior to being destroyed). Fix this by not creating a `llvm::Error` value in advance, and directly returning the result of `llvm::make_error` instead, whenever an error is encountered. See also: <https://bugs.freebsd.org/253881> and <https://bugs.freebsd.org/257829>. Reviewed By: teemperor Differential Revision: https://reviews.llvm.org/D108088 Reported by: dmgk, ota@j.email.ne.jp PR: 253881, 257829 MFC after: 3 days .../llvm-project/lldb/source/Symbol/TypeSystem.cpp | 90 +++++++++------------- 1 file changed, 38 insertions(+), 52 deletions(-) A commit in branch stable/13 references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=a949c6a0d6c83994471e33c8ea60f1509e691f6c commit a949c6a0d6c83994471e33c8ea60f1509e691f6c Author: Dimitry Andric <dim@FreeBSD.org> AuthorDate: 2021-08-16 16:56:41 +0000 Commit: Dimitry Andric <dim@FreeBSD.org> CommitDate: 2021-08-20 16:21:46 +0000 Apply upstream lldb fix for unhandled Error causing abort Merge commit 5033f0793fe6 from llvm git (by Dimitry Andric): [lldb] Avoid unhandled Error in TypeSystemMap::GetTypeSystemForLanguage When assertions are turned off, the `llvm::Error` value created at the start of this function is overwritten using the move-assignment operator, but the success value is never checked. Whenever a TypeSystem cannot be found or created, this can lead to lldb core dumping with: Program aborted due to an unhandled Error: Error value was Success. (Note: Success values must still be checked prior to being destroyed). Fix this by not creating a `llvm::Error` value in advance, and directly returning the result of `llvm::make_error` instead, whenever an error is encountered. See also: <https://bugs.freebsd.org/253881> and <https://bugs.freebsd.org/257829>. Reviewed By: teemperor Differential Revision: https://reviews.llvm.org/D108088 Reported by: dmgk, ota@j.email.ne.jp PR: 253881, 257829 (cherry picked from commit c1a540709a83f810aa47380b946552ab20020374) .../llvm-project/lldb/source/Symbol/TypeSystem.cpp | 90 +++++++++------------- 1 file changed, 38 insertions(+), 52 deletions(-) A commit in branch stable/12 references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=456e2b149ecb1ea5f9e81b9b0733c7ec9526b8c2 commit 456e2b149ecb1ea5f9e81b9b0733c7ec9526b8c2 Author: Dimitry Andric <dim@FreeBSD.org> AuthorDate: 2021-08-16 16:56:41 +0000 Commit: Dimitry Andric <dim@FreeBSD.org> CommitDate: 2021-12-25 11:51:16 +0000 Apply upstream lldb fix for unhandled Error causing abort Merge commit 5033f0793fe6 from llvm git (by Dimitry Andric): [lldb] Avoid unhandled Error in TypeSystemMap::GetTypeSystemForLanguage When assertions are turned off, the `llvm::Error` value created at the start of this function is overwritten using the move-assignment operator, but the success value is never checked. Whenever a TypeSystem cannot be found or created, this can lead to lldb core dumping with: Program aborted due to an unhandled Error: Error value was Success. (Note: Success values must still be checked prior to being destroyed). Fix this by not creating a `llvm::Error` value in advance, and directly returning the result of `llvm::make_error` instead, whenever an error is encountered. See also: <https://bugs.freebsd.org/253881> and <https://bugs.freebsd.org/257829>. Reviewed By: teemperor Differential Revision: https://reviews.llvm.org/D108088 Reported by: dmgk, ota@j.email.ne.jp PR: 253881, 257829 MFC after: 3 days (cherry picked from commit c1a540709a83f810aa47380b946552ab20020374) .../llvm-project/lldb/source/Symbol/TypeSystem.cpp | 90 +++++++++------------- 1 file changed, 38 insertions(+), 52 deletions(-) ^Triage: committed back in 2021. |