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| author | Lianbo Jiang <lijiang@redhat.com> | 2019-08-23 20:05:39 +0800 |
|---|---|---|
| committer | Simon Horman <horms@verge.net.au> | 2019-09-08 13:26:56 +0100 |
| commit | fa3f0ed47f3e6dbee485722d13713ad495571b7e (patch) | |
| tree | 10799e8006176e42e4a011d3c1950a2a0290069b | |
| parent | a7c4cb8e998571cb3dd62e907935a1e052b15d6c (diff) | |
| download | kexec-tools-fa3f0ed47f3e6dbee485722d13713ad495571b7e.tar.gz | |
Limit the size of vmcore-dmesg.txt to 2G
With some corrupted vmcore files, the vmcore-dmesg.txt file may grow
forever till the kdump disk becomes full, and also probably causes
the disk error messages as follow:
...
sd 0:0:0:0: [sda] tag#6 FAILED Result: hostbyte=DID_BAD_TARGET driverbyte=DRIVER_OK
sd 0:0:0:0: [sda] tag#6 CDB: Read(10) 28 00 08 06 4c 98 00 00 08 00
blk_update_request: I/O error, dev sda, sector 134630552
sd 0:0:0:0: [sda] tag#7 FAILED Result: hostbyte=DID_BAD_TARGET driverbyte=DRIVER_OK
sd 0:0:0:0: [sda] tag#7 CDB: Read(10) 28 00 08 06 4c 98 00 00 08 00
blk_update_request: I/O error, dev sda, sector 134630552
...
If vmcore-dmesg.txt occupies the whole disk, the vmcore can not be
saved, this is also a problem.
Lets limit the size of vmcore-dmesg.txt to avoid such problems.
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
| -rw-r--r-- | vmcore-dmesg/vmcore-dmesg.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/vmcore-dmesg/vmcore-dmesg.c b/vmcore-dmesg/vmcore-dmesg.c index fe7df8ec..81c2a58c 100644 --- a/vmcore-dmesg/vmcore-dmesg.c +++ b/vmcore-dmesg/vmcore-dmesg.c @@ -5,9 +5,19 @@ typedef Elf32_Nhdr Elf_Nhdr; extern const char *fname; +/* stole this macro from kernel printk.c */ +#define LOG_BUF_LEN_MAX (uint32_t)(1 << 31) + static void write_to_stdout(char *buf, unsigned int nr) { ssize_t ret; + static uint32_t n_bytes = 0; + + n_bytes += nr; + if (n_bytes > LOG_BUF_LEN_MAX) { + fprintf(stderr, "The vmcore-dmesg.txt over 2G in size is not supported.\n"); + exit(53); + } ret = write(STDOUT_FILENO, buf, nr); if (ret != nr) { |