From fc5e0925d4bff79c8c036cf00803112a1ec04188 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Sat, 15 May 2021 14:36:26 +0930 Subject: _mul_overflow and get_encoded_value A sufficiently mad compiler optimiser can take undefined behaviour according to the C standard as an opportunity to remove code. Since "data + size" might be seen to be past the end of an array, calculating such an expression is UB. _mul_overflow is infrastructure for later patches. * bucomm.h (_mul_overflow): Define. * dwarf.c (get_encoded_value): Avoid pointer UB. --- binutils/dwarf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'binutils/dwarf.c') diff --git a/binutils/dwarf.c b/binutils/dwarf.c index 2794a15..020b7e0 100644 --- a/binutils/dwarf.c +++ b/binutils/dwarf.c @@ -178,7 +178,7 @@ get_encoded_value (unsigned char **pdata, unsigned int size = size_of_encoded_value (encoding); dwarf_vma val; - if (data + size >= end) + if (data >= end || size > (size_t) (end - data)) { warn (_("Encoded value extends past end of section\n")); * pdata = end; -- cgit v1.1