diff options
| author | Cliff Wickman <cpw@sgi.com> | 2010-08-23 16:18:05 -0500 |
|---|---|---|
| committer | Simon Horman <horms@verge.net.au> | 2010-08-24 10:22:02 +0900 |
| commit | 242acd25db83d99a8f6ea48d14c215dd64f3635f (patch) | |
| tree | a118d4b205885a3f3c103cd68954e4bea833d943 | |
| parent | 3f2012bd7947ec327dc942ab91f115388630cc36 (diff) | |
kexec: extend KCORE_ELF_HEADERS_SIZE for large memory
A customer has seen the kexec command exhaust its buffer for the ELF headers
from /proc/kcore. It found 147 program headers, which requires a buffer of
over 8k.
(This overflow was on an SGI UV with an extremely large memory, hence
many ram ranges.)
The default buffer size of 4k is configured in KCORE_ELF_HEADERS_SIZE.
The easy solution would probably be to increase the buffer to 16k.
That is room for 291 entries, on x86_64.
You might want to make the command dynamically enlarge the buffer when
it is found to be too small, but I don't think this command's use of a
little more memory is of concern. So there is probably no reason to
change the program logic in this area.
Diffed against kexec-tools-2.0.2
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
| -rw-r--r-- | kexec/crashdump.h | 4 | ||||
| -rw-r--r-- | kexec/kexec-elf.c | 4 |
2 files changed, 6 insertions, 2 deletions
diff --git a/kexec/crashdump.h b/kexec/crashdump.h index b6e60cc..31f711c 100644 --- a/kexec/crashdump.h +++ b/kexec/crashdump.h @@ -7,8 +7,8 @@ extern int get_xen_vmcoreinfo(uint64_t *addr, uint64_t *len); /* Need to find a better way to determine per cpu notes section size. */ #define MAX_NOTE_BYTES 1024 -/* Expecting ELF headers to fit in 4K. Increase it if you need more. */ -#define KCORE_ELF_HEADERS_SIZE 4096 +/* Expecting ELF headers to fit in 16K. Increase it if you need more. */ +#define KCORE_ELF_HEADERS_SIZE 16384 /* The address of the ELF header is passed to the secondary kernel * using the kernel command line option memmap=nnn. * The smallest unit the kernel accepts is in kilobytes, diff --git a/kexec/kexec-elf.c b/kexec/kexec-elf.c index 85d1765..1cdae36 100644 --- a/kexec/kexec-elf.c +++ b/kexec/kexec-elf.c @@ -8,6 +8,7 @@ #include <boot/elf_boot.h> #include "kexec.h" #include "kexec-elf.h" +#include "crashdump.h" static const int probe_debug = 0; @@ -389,6 +390,9 @@ static int build_mem_phdrs(const char *buf, off_t len, struct mem_ehdr *ehdr, phdr_size *= ehdr->e_phnum; if ((uintmax_t)(ehdr->e_phoff + phdr_size) > (uintmax_t)len) { /* The program header did not fit in the file buffer */ + fprintf(stderr, "%d segments require a %ld-byte buffer\n", + ehdr->e_phnum, ehdr->e_phoff + phdr_size); + fprintf(stderr, "KCORE_ELF_HEADERS_SIZE %d too small\n", KCORE_ELF_HEADERS_SIZE); if (probe_debug) { fprintf(stderr, "ELF program segment truncated\n"); } |