diff options
| author | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2018-02-23 11:12:19 +0100 |
|---|---|---|
| committer | Sven Eden <yamakuzure@gmx.net> | 2018-05-30 07:59:04 +0200 |
| commit | a7956ba5bf0dd2b9bd68111d1dc61ac77e6a9e38 (patch) | |
| tree | 2756941b962cc080acc5584a30e44d443fa411eb /src | |
| parent | b5d08e33f89723a18c8452f084551192dbec31b1 (diff) | |
udev/net-id: check all snprintf return values
gcc-8 throws an error if it knows snprintf might truncate output and the
return value is ignored:
../src/udev/udev-builtin-net_id.c: In function 'dev_pci_slot':
../src/udev/udev-builtin-net_id.c:297:47: error: '%s' directive output may be truncated writing up to 255 bytes into a region of size between 0 and 4095 [-Werror=format-truncation=]
snprintf(str, sizeof str, "%s/%s/address", slots, dent->d_name);
^~
../src/udev/udev-builtin-net_id.c:297:17: note: 'snprintf' output between 10 and 4360 bytes into a destination of size 4096
snprintf(str, sizeof str, "%s/%s/address", slots, dent->d_name);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors
Let's check all return values. This actually makes the code better, because there's
no point in trying to open a file when the name has been truncated, etc.
Diffstat (limited to 'src')
| -rw-r--r-- | src/basic/stdio-util.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/src/basic/stdio-util.h b/src/basic/stdio-util.h index f4dfa7629..f818a208a 100644 --- a/src/basic/stdio-util.h +++ b/src/basic/stdio-util.h @@ -31,9 +31,11 @@ #include "macro.h" -#define xsprintf(buf, fmt, ...) \ - assert_message_se((size_t) snprintf(buf, ELEMENTSOF(buf), fmt, __VA_ARGS__) < ELEMENTSOF(buf), "xsprintf: " #buf "[] must be big enough") +#define snprintf_ok(buf, len, fmt, ...) \ + ((size_t) snprintf(buf, len, fmt, __VA_ARGS__) < (len)) +#define xsprintf(buf, fmt, ...) \ + assert_message_se(snprintf_ok(buf, ELEMENTSOF(buf), fmt, __VA_ARGS__), "xsprintf: " #buf "[] must be big enough") #define VA_FORMAT_ADVANCE(format, ap) \ do { \ |