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<base href="https://bugs.llvm.org/">
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<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Incorrect call frame info on X86_64 target"
href="https://bugs.llvm.org/show_bug.cgi?id=50327">50327</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Incorrect call frame info on X86_64 target
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>DebugInfo
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>djordje.todorovic@syrmia.com
</td>
</tr>
<tr>
<th>CC</th>
<td>jdevlieghere@apple.com, keith.walker@arm.com, llvm-bugs@lists.llvm.org, paul_robinson@playstation.sony.com
</td>
</tr></table>
<p>
<div>
<pre>$ cat test.c
#include <stdlib.h>
int f2(char *input) { return crasher(input, 1); }
int crasher(char *input, int crash) {
if (crash)
input = NULL;
input[0] = '1';
input[1] = '2';
input[2] = '3';
input[3] = '\0';
f2(input);
if (crash)
return 0;
else
return 1;
}
int f1() {
char *input = (char *)malloc(sizeof(char) * 10);
return crasher(input, 0);
}
int main(int argc, char **argv) {
f1();
return 0;
}
This small example when compiled with -O1 produces call frame info that causes
incorrect backtrace in GDB.
$ clang -O1 test.c -o test
$ ./test
Segmentation fault (core dumped)
$ lldb test -c core.test
...
(lldb) bt
* thread #1, name = 'test', stop reason = signal SIGSEGV
* frame #0: 0x0000000000401156 test`f2 + 6
frame #1: 0x000000000040116c test`crasher + 12
frame #2: 0x000000000040115b test`f2 + 11
frame #3: 0x000000000040116c test`crasher + 12
frame #4: 0x000000000040115b test`f2 + 11
frame #5: 0x000000000040116c test`crasher + 12
frame #6: 0x000000000040115b test`f2 + 11
frame #7: 0x000000000040116c test`crasher + 12
frame #8: 0x000000000040115b test`f2 + 11
frame #9: 0x000000000040116c test`crasher + 12
frame #10: 0x000000000040115b test`f2 + 11
frame #11: 0x000000000040116c test`crasher + 12
frame #12: 0x000000000040115b test`f2 + 11
frame #13: 0x000000000040116c test`crasher + 12
...
With gcc, it looks ok:
$ gcc -O1 test.c -o test-gcc
$ ./test-gcc
Segmentation fault (core dumped)
$ lldb ./test-gcc -c core.test-gcc
...
(lldb) bt
* thread #1, name = 'test-gcc', stop reason = signal SIGSEGV
* frame #0: 0x000000000040115b test-gcc`crasher + 14
frame #1: 0x000000000040118c test-gcc`f2 + 19
frame #2: 0x000000000040116f test-gcc`crasher + 34
frame #3: 0x00000000004011ac test-gcc`f1 + 27
frame #4: 0x00000000004011bf test-gcc`main + 14
frame #5: 0x00007fea1df1c555 libc.so.6`__libc_start_main + 245
frame #6: 0x0000000000401089 test-gcc`_start + 41
This has been reproduced with x86_64 GNU/Linux platform.</pre>
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