Messages in this thread Patch in this message | | | From | Eric Biggers <> | Subject | [PATCH] PM: declare __tracedata symbols as char[] rather than char | Date | Sun, 24 Jan 2016 20:08:52 -0600 |
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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 <ebiggers3@gmail.com> --- 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 a311cfa..a697579 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); -- 2.7.0
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