lkml.org 
[lkml]   [2021]   [Apr]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.4 37/38] perf map: Tighten snprintf() string precision to pass gcc check on some 32-bit arches
    Date
    From: Arnaldo Carvalho de Melo <acme@redhat.com>

    commit 77d02bd00cea9f1a87afe58113fa75b983d6c23a upstream.

    Noticed on a debian:experimental mips and mipsel cross build build
    environment:

    perfbuilder@ec265a086e9b:~$ mips-linux-gnu-gcc --version | head -1
    mips-linux-gnu-gcc (Debian 10.2.1-3) 10.2.1 20201224
    perfbuilder@ec265a086e9b:~$

    CC /tmp/build/perf/util/map.o
    util/map.c: In function 'map__new':
    util/map.c:109:5: error: '%s' directive output may be truncated writing between 1 and 2147483645 bytes into a region of size 4096 [-Werror=format-truncation=]
    109 | "%s/platforms/%s/arch-%s/usr/lib/%s",
    | ^~
    In file included from /usr/mips-linux-gnu/include/stdio.h:867,
    from util/symbol.h:11,
    from util/map.c:2:
    /usr/mips-linux-gnu/include/bits/stdio2.h:67:10: note: '__builtin___snprintf_chk' output 32 or more bytes (assuming 4294967321) into a destination of size 4096
    67 | return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
    | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    68 | __bos (__s), __fmt, __va_arg_pack ());
    | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    cc1: all warnings being treated as errors

    Since we have the lenghts for what lands in that place, use it to give
    the compiler more info and make it happy.

    Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
    Cc: Anders Roxell <anders.roxell@linaro.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    tools/perf/util/map.c | 7 +++----
    1 file changed, 3 insertions(+), 4 deletions(-)

    --- a/tools/perf/util/map.c
    +++ b/tools/perf/util/map.c
    @@ -88,8 +88,7 @@ static inline bool replace_android_lib(c
    if (!strncmp(filename, "/system/lib/", 12)) {
    char *ndk, *app;
    const char *arch;
    - size_t ndk_length;
    - size_t app_length;
    + int ndk_length, app_length;

    ndk = getenv("NDK_ROOT");
    app = getenv("APP_PLATFORM");
    @@ -117,8 +116,8 @@ static inline bool replace_android_lib(c
    if (new_length > PATH_MAX)
    return false;
    snprintf(newfilename, new_length,
    - "%s/platforms/%s/arch-%s/usr/lib/%s",
    - ndk, app, arch, libname);
    + "%.*s/platforms/%.*s/arch-%s/usr/lib/%s",
    + ndk_length, ndk, app_length, app, arch, libname);

    return true;
    }

    \
     
     \ /
      Last update: 2021-04-15 16:51    [W:4.538 / U:0.012 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site