From mboxrd@z Thu Jan 1 00:00:00 1970 From: ben.hutchings@codethink.co.uk (Ben Hutchings) Date: Fri, 09 Dec 2016 00:34:13 +0000 Subject: [cip-dev] [PATCH 4.4-cip 03/23] PM / sleep: declare __tracedata symbols as char[] rather than char In-Reply-To: <1481243545.1860.156.camel@codethink.co.uk> References: <1481243545.1860.156.camel@codethink.co.uk> Message-ID: <1481243653.1860.159.camel@codethink.co.uk> To: cip-dev@lists.cip-project.org List-Id: cip-dev.lists.cip-project.org From: Eric Biggers commit f97238373b8662a6d580e204df2e7bcbfa43e27a upstream. Accessing more than one byte from a symbol declared simply 'char' is undefined behavior, as reported by UBSAN: UBSAN: Undefined behaviour in drivers/base/power/trace.c:178:18 load of address ffffffff8203fc78 with insufficient space for an object of type 'char' Avoid this by declaring the symbols as arrays. Signed-off-by: Eric Biggers Signed-off-by: Rafael J. Wysocki Signed-off-by: Ben Hutchings --- drivers/base/power/trace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/base/power/trace.c b/drivers/base/power/trace.c index a311cfa4c5bd..a6975795e7f3 100644 --- a/drivers/base/power/trace.c +++ b/drivers/base/power/trace.c @@ -166,14 +166,14 @@ void generate_pm_trace(const void *tracedata, unsigned int user) } EXPORT_SYMBOL(generate_pm_trace); -extern char __tracedata_start, __tracedata_end; +extern char __tracedata_start[], __tracedata_end[]; static int show_file_hash(unsigned int value) { int match; char *tracedata; match = 0; - for (tracedata = &__tracedata_start ; tracedata < &__tracedata_end ; + for (tracedata = __tracedata_start ; tracedata < __tracedata_end ; tracedata += 2 + sizeof(unsigned long)) { unsigned short lineno = *(unsigned short *)tracedata; const char *file = *(const char **)(tracedata + 2); -- 2.10.2 -- Ben Hutchings Software Developer, Codethink Ltd.