On Fri, Aug 20, 2010 at 05:35:58PM +0800, Xiaotian Feng wrote: > We met a parameter truncated issue, consider following: > > echo "|/root/core_pattern_pipe_test %p /usr/libexec/blah-blah-blah \ > %s %c %p %u %g 11 12345678901234567890123456789012345678 %t" > \ > /proc/sys/kernel/core_pattern > > This is okay because the strings is less than CORENAME_MAX_SIZE. > "cat /proc/sys/kernel/core_pattern" shows the whole string. but > after we run core_pattern_pipe_test in man page, we found last > parameter was truncated like below: > argc[10]=<12807486> > > The root cause is core_pattern allows % specifiers, which need to be > replaced during parse time, but the replace may expand the strings > to larger than CORENAME_MAX_SIZE. So if the last parameter is % > specifiers, the replace code is using snprintf(out_ptr, out_end - out_ptr, ...), > this will write out of corename array. > > Changes since v2: > Introduced generic function cn_printf and make format_corename remember the time > has been expanded. > > Changes since v1: > This patch allocates corename at runtime, if the replace doesn't have enough > memory, expand the corename dynamically. > > Signed-off-by: Xiaotian Feng <dfeng@xxxxxxxxxx> > Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Oleg Nesterov <oleg@xxxxxxxxxx> > Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> > Cc: Neil Horman <nhorman@xxxxxxxxxxxxx> > Cc: Roland McGrath <roland@xxxxxxxxxx> > --- > fs/exec.c | 180 ++++++++++++++++++++++++++++++++++++++++-------------------- > 1 files changed, 120 insertions(+), 60 deletions(-) > This looks alot cleaner. Thanks! Reviewed-by: Neil Horman <nhorman@xxxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
