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Subject[PATCH 1/2] tomoyo: use vsnprintf() properly
Idiomatic way to find how much space sprintf output would take is
len = snprintf(NULL, 0, ...) + 1;
Once upon a time there'd been libc implementations that blew chunks
on that and somebody had come up with the following "cute" trick:
len = snprintf((char *) &len, 1, ...) + 1;
for doing the same. However, that's unidiomatic, harder to follow
*and* any such libc implementation would violate both C99 and POSIX
(since 2001).
IOW, this kludge is best buried along with such libc implementations,
nevermind getting cargo-culted into newer code. Our vsnprintf() does not
suffer that braindamage, TYVM.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
security/tomoyo/audit.c | 2 +-
security/tomoyo/common.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/security/tomoyo/audit.c b/security/tomoyo/audit.c
index 023bedd9dfa3..7cf8fdbb29bf 100644
--- a/security/tomoyo/audit.c
+++ b/security/tomoyo/audit.c
@@ -423,7 +423,7 @@ void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...)
int len;

va_start(args, fmt);
- len = vsnprintf((char *) &len, 1, fmt, args) + 1;
+ len = vsnprintf(NULL, 0, fmt, args) + 1;
va_end(args);
va_start(args, fmt);
tomoyo_write_log2(r, len, fmt, args);
diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index ff17abc96e5c..f4cd9b58b205 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -2057,7 +2057,7 @@ int tomoyo_supervisor(struct tomoyo_request_info *r, const char *fmt, ...)
bool quota_exceeded = false;

va_start(args, fmt);
- len = vsnprintf((char *) &len, 1, fmt, args) + 1;
+ len = vsnprintf(NULL, 0, fmt, args) + 1;
va_end(args);
/* Write /sys/kernel/security/tomoyo/audit. */
va_start(args, fmt);
--
2.30.2
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