On 20/11/23 22:45, Paolo Bonzini wrote:
From: Philippe Mathieu-Daudé <phi...@linaro.org>
Propagate the buffer size to format_dec() and use snprintf().
This should silence this UBSan -Wformat-overflow warning:
"produced when using GCC 12.1.0:"
In file included from /usr/include/stdio.h:906,
from include/qemu/osdep.h:114,
from ../disas/cris.c:21:
In function 'sprintf',
inlined from 'format_dec' at ../disas/cris.c:1737:3,
inlined from 'print_with_operands' at ../disas/cris.c:2477:12,
inlined from 'print_insn_cris_generic.constprop' at
../disas/cris.c:2690:8:
/usr/include/bits/stdio2.h:30:10: warning: null destination pointer
[-Wformat-overflow=]
30 | return __builtin___sprintf_chk (__s, __USE_FORTIFY_LEVEL - 1,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
31 | __glibc_objsize (__s), __fmt,
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
32 | __va_arg_pack ());
| ~~~~~~~~~~~~~~~~~
Reported-by: Akihiko Odaki <akihiko.od...@daynix.com>
Signed-off-by: Philippe Mathieu-Daudé <phi...@linaro.org>
Message-ID: <20231120132222.82138-1-phi...@linaro.org>
[Rewritten to fix logic and avoid repeated expression. - Paolo]
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
disas/cris.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)
diff --git a/disas/cris.c b/disas/cris.c
index 0b0a3fb9165..409a224c5d1 100644
--- a/disas/cris.c
+++ b/disas/cris.c
@@ -1731,10 +1731,10 @@ format_hex (unsigned long number,
unsigned (== 0). */
static char *
-format_dec (long number, char *outbuffer, int signedp)
+format_dec (long number, char *outbuffer, size_t outsize, int signedp)
{
last_immediate = number;
- sprintf (outbuffer, signedp ? "%ld" : "%lu", number);
+ snprintf (outbuffer, outsize, signedp ? "%ld" : "%lu", number);
return outbuffer + strlen (outbuffer);
}
@@ -1876,6 +1876,12 @@ print_flags (struct cris_disasm_data *disdata, unsigned
int insn, char *cp)
return cp;
}
+#define FORMAT_DEC(number, tp, signedp) \
+ format_dec (number, tp, ({ \
+ assert(tp >= temp && tp <= temp + sizeof(temp)); \
+ temp + sizeof(temp) - tp; \
+ }), signedp)
Thank you Paolo for this respin!
Reviewed-by: Philippe Mathieu-Daudé <phi...@linaro.org>
