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firmware: tegra: fix strncpy()/strncat() confusion

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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>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
This commit is contained in:
Arnd Bergmann 2020-10-26 17:49:21 +01:00 committed by Thierry Reding
parent 3650b228f8
commit 9294996f0b
1 changed files with 1 additions and 5 deletions
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6
drivers/firmware/tegra/bpmp-debugfs.c
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@ -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)