From: Sergei Trofimovich slyich@gmail.com
[ Upstream commit 82880283d7fcd0a1d20964a56d6d1a5cc0df0713 ]
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 kilobyte@angband.pl Reported-by: Martin Liška mliska@suse.cz Signed-off-by: Sergei Trofimovich slyich@gmail.com Signed-off-by: Josh Poimboeuf jpoimboe@redhat.com Link: https://lore.kernel.org/r/20220120233748.2062559-1-slyich@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 21735829b860c..750ef1c446c8a 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -2823,7 +2823,7 @@ 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;