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 <[email protected]> --- vmcore-dmesg/vmcore-dmesg.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/vmcore-dmesg/vmcore-dmesg.c b/vmcore-dmesg/vmcore-dmesg.c index ff0d540c9130..5ada3566972b 100644 --- a/vmcore-dmesg/vmcore-dmesg.c +++ b/vmcore-dmesg/vmcore-dmesg.c @@ -1,8 +1,18 @@ #include <elf_info.h> +/* 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(55); + } ret = write(STDOUT_FILENO, buf, nr); if (ret != nr) { -- 2.17.1 _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
