From 82880283d7fcd0a1d20964a56d6d1a5cc0df0713 Mon Sep 17 00:00:00 2001 From: Sergei Trofimovich Date: Thu, 20 Jan 2022 23:37:48 +0000 Subject: [PATCH] objtool: Fix truncated string warning MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On GCC 12, the build fails due to a possible truncated string: check.c: In function 'validate_call': check.c:2865:58: error: '%d' directive output may be truncated writing between 1 and 10 bytes into a region of size 9 [-Werror=format-truncation=] 2865 | snprintf(pvname, sizeof(pvname), "pv_ops[%d]", idx); | ^~ In theory it's a valid bug: static char pvname[16]; int idx; ... idx = (rel->addend / sizeof(void *)); snprintf(pvname, sizeof(pvname), "pv_ops[%d]", idx); There are only 7 chars for %d while it could take up to 9, so the printed "pv_ops[%d]" string could get truncated. In reality the bug should never happen, because pv_ops only has ~80 entries, so 7 chars for the integer is more than enough. Still, it's worth fixing. Bump the buffer size by 2 bytes to silence the warning. [ jpoimboe: changed size to 19; massaged changelog ] Fixes: db2b0c5d7b6f ("objtool: Support pv_opsindirect calls for noinstr") Reported-by: Adam Borowski Reported-by: Martin Liška Signed-off-by: Sergei Trofimovich Signed-off-by: Josh Poimboeuf Link: https://lore.kernel.org/r/20220120233748.2062559-1-slyich@gmail.com --- tools/objtool/check.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index c2d2ab9a2861..7c33ec67c4a9 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -2854,7 +2854,7 @@ static inline bool func_uaccess_safe(struct symbol *func) static inline const char *call_dest_name(struct instruction *insn) { - static char pvname[16]; + static char pvname[19]; struct reloc *rel; int idx;