Hi,
I am using MALLOC_OPTIONS=D and kdump report no information when
malloc() exceeds 1073500000 bytes on my OpenBSD box. I have
investigated and found that mmap() faild in putleakinfo().
I used the following program:
#include <err.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
int
main(int argc, char *argv[])
{
size_t size;
void *buf;
char *end;
if (argc != 2) {
fprintf(stderr, "usage: ./a.out size\n");
exit(1);
}
size = strtol(argv[1], &end, 0);
if (argv[1] == end) {
fprintf(stderr, "Invalid argument: %s\n", argv[1]);
exit(1);
}
if (*end == 'k')
size *= 1024;
else if (*end == 'm')
size *= 1024 * 1024;
else if (*end == 'g')
size *= 1024 * 1024 * 1024;
if ((buf = malloc(size)) == NULL)
err(1, "malloc");
return (0);
}
I used this program to perform the following:
$ MALLOC_OPTIONS=D ktrace -tu ./a.out 1073490000
$ kdump -u malloc
******** Start dump a.out *******
M=8 I=1 F=0 U=0 J=1 R=0 X=0 C=0 cache=64 G=0
Leak report:
f sum # avg
0xeb017e21c6f 1073490000 1 1073490000 addr2line -e ./a.out
0x1c6f
******** End dump a.out *******
$ MALLOC_OPTIONS=D ktrace -tu ./a.out 1073500000
$ kdump -u malloc
$ ls -l ktrace.out
-rw------- 1 asou asou 64 Sep 7 18:38 ktrace.out
$ export LD_LIBRARY_PATH=/usr/obj/lib/libc
$ MALLOC_OPTIONS=D ktrace -tu ./a.out 1073500000
/usr/src/lib/libc/stdlib/malloc.c: putleakinfo: Cannot allocate memory
$
In such a case, shouldn't an error message be displayed? I made a
patch for print error message if mmap() was failed.
comments, ok?
--
ASOU Masato
Index: lib/libc/stdlib/malloc.c
===================================================================
RCS file: /cvs/src/lib/libc/stdlib/malloc.c,v
retrieving revision 1.289
diff -u -p -r1.289 malloc.c
--- lib/libc/stdlib/malloc.c 30 Jun 2023 06:24:58 -0000 1.289
+++ lib/libc/stdlib/malloc.c 7 Sep 2023 09:44:59 -0000
@@ -2354,7 +2354,14 @@ putleakinfo(struct leaktree *leaks, void
used >= MALLOC_PAGESIZE / sizeof(struct leaknode)) {
page = MMAP(MALLOC_PAGESIZE, 0);
if (page == MAP_FAILED)
+ {
+ char buf[256];
+
+ snprintf(buf, sizeof (buf), "%s: %s: %s\n",
+ __FILE__, __func__, strerror(errno));
+ write(STDERR_FILENO, buf, strlen(buf));
return;
+ }
used = 0;
}
p = &page[used++];
