From: Arnd Bergmann <arnd@kernel.org>
To: Thierry Reding <thierry.reding@gmail.com>,
Jonathan Hunter <jonathanh@nvidia.com>
Cc: Arvind Sankar <nivedita@alum.mit.edu>,
Arnd Bergmann <arnd@arndb.de>,
Thierry Reding <treding@nvidia.com>, Timo Alho <talho@nvidia.com>,
linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] [v2] firmware: tegra: fix strncpy()/strncat() confusion
Date: Mon, 26 Oct 2020 17:49:21 +0100 [thread overview]
Message-ID: <20201026164937.3722420-1-arnd@kernel.org> (raw)
From: Arnd Bergmann <arnd@arndb.de>
The way that bpmp_populate_debugfs_inband() uses strncpy()
and strncat() makes no sense since the size argument for
the first is insufficient to contain the trailing '/'
and the second passes the length of the input rather than
the output, which triggers a warning:
In function 'strncat',
inlined from 'bpmp_populate_debugfs_inband' at ../drivers/firmware/tegra/bpmp-debugfs.c:422:4:
include/linux/string.h:289:30: warning: '__builtin_strncat' specified bound depends on the length of the source argument [-Wstringop-overflow=]
289 | #define __underlying_strncat __builtin_strncat
| ^
include/linux/string.h:367:10: note: in expansion of macro '__underlying_strncat'
367 | return __underlying_strncat(p, q, count);
| ^~~~~~~~~~~~~~~~~~~~
drivers/firmware/tegra/bpmp-debugfs.c: In function 'bpmp_populate_debugfs_inband':
include/linux/string.h:288:29: note: length computed here
288 | #define __underlying_strlen __builtin_strlen
| ^
include/linux/string.h:321:10: note: in expansion of macro '__underlying_strlen'
321 | return __underlying_strlen(p);
Simplify this to use an snprintf() instead.
Fixes: 5e37b9c137ee ("firmware: tegra: Add support for in-band debug")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
v2: Use the correct arguments for snprintf(), as pointed out by Arvind Sankar
---
drivers/firmware/tegra/bpmp-debugfs.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/firmware/tegra/bpmp-debugfs.c b/drivers/firmware/tegra/bpmp-debugfs.c
index c1bbba9ee93a..440d99c63638 100644
--- a/drivers/firmware/tegra/bpmp-debugfs.c
+++ b/drivers/firmware/tegra/bpmp-debugfs.c
@@ -412,16 +412,12 @@ static int bpmp_populate_debugfs_inband(struct tegra_bpmp *bpmp,
goto out;
}
- len = strlen(ppath) + strlen(name) + 1;
+ len = snprintf(pathbuf, pathlen, "%s%s/", ppath, name);
if (len >= pathlen) {
err = -EINVAL;
goto out;
}
- strncpy(pathbuf, ppath, pathlen);
- strncat(pathbuf, name, strlen(name));
- strcat(pathbuf, "/");
-
err = bpmp_populate_debugfs_inband(bpmp, dentry,
pathbuf);
if (err < 0)
--
2.27.0
next reply other threads:[~2020-10-26 16:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-26 16:49 Arnd Bergmann [this message]
2020-10-27 9:04 ` [PATCH] [v2] firmware: tegra: fix strncpy()/strncat() confusion Jon Hunter
2020-11-10 19:16 ` Thierry Reding
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