98efe7c2fd
clang-tidy, starting from LLVM version 16, up to at least LLVM version
19, now checks that we detect and handle errors for snprintf() as
requested by CERT C rule ERR33-C. These warnings were logged with LLVM
version 19.1.2 (at least Debian and Fedora match):
/home/sbrivio/passt/arch.c:43:3: error: the value returned by this function should not be disregarded; neglecting it may lead to errors [cert-err33-c,-warnings-as-errors]
43 | snprintf(new_path, PATH_MAX + sizeof(".avx2"), "%s.avx2", exe);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/sbrivio/passt/arch.c:43:3: note: cast the expression to void to silence this warning
/home/sbrivio/passt/conf.c:577:4: error: the value returned by this function should not be disregarded; neglecting it may lead to errors [cert-err33-c,-warnings-as-errors]
577 | snprintf(netns, PATH_MAX, "/proc/%ld/ns/net", pidval);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/sbrivio/passt/conf.c:577:4: note: cast the expression to void to silence this warning
/home/sbrivio/passt/conf.c:579:5: error: the value returned by this function should not be disregarded; neglecting it may lead to errors [cert-err33-c,-warnings-as-errors]
579 | snprintf(userns, PATH_MAX, "/proc/%ld/ns/user",
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
580 | pidval);
| ~~~~~~~
/home/sbrivio/passt/conf.c:579:5: note: cast the expression to void to silence this warning
/home/sbrivio/passt/pasta.c:105:2: error: the value returned by this function should not be disregarded; neglecting it may lead to errors [cert-err33-c,-warnings-as-errors]
105 | snprintf(ns, PATH_MAX, "/proc/%i/ns/net", pasta_child_pid);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/sbrivio/passt/pasta.c:105:2: note: cast the expression to void to silence this warning
/home/sbrivio/passt/pasta.c:242:2: error: the value returned by this function should not be disregarded; neglecting it may lead to errors [cert-err33-c,-warnings-as-errors]
242 | snprintf(uidmap, BUFSIZ, "0 %u 1", uid);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/sbrivio/passt/pasta.c:242:2: note: cast the expression to void to silence this warning
/home/sbrivio/passt/pasta.c:243:2: error: the value returned by this function should not be disregarded; neglecting it may lead to errors [cert-err33-c,-warnings-as-errors]
243 | snprintf(gidmap, BUFSIZ, "0 %u 1", gid);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/sbrivio/passt/pasta.c:243:2: note: cast the expression to void to silence this warning
/home/sbrivio/passt/tap.c:1155:4: error: the value returned by this function should not be disregarded; neglecting it may lead to errors [cert-err33-c,-warnings-as-errors]
1155 | snprintf(path, UNIX_PATH_MAX - 1, UNIX_SOCK_PATH, i);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/sbrivio/passt/tap.c:1155:4: note: cast the expression to void to silence this warning
Don't silence the warnings as they might actually have some merit. Add
an snprintf_check() function, instead, checking that we're not
truncating messages while printing to buffers, and terminate if the
check fails.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
54 lines
1.2 KiB
C
54 lines
1.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* PASST - Plug A Simple Socket Transport
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* for qemu/UNIX domain socket mode
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*
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* PASTA - Pack A Subtle Tap Abstraction
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* for network namespace/tap device mode
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*
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* arch.c - Architecture-specific implementations
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*
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* Copyright (c) 2022 Red Hat GmbH
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* Author: Stefano Brivio <sbrivio@redhat.com>
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*/
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#include <limits.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "log.h"
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#include "util.h"
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/**
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* arch_avx2_exec() - Switch to AVX2 build if supported
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* @argv: Arguments from command line
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*/
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#ifdef __x86_64__
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void arch_avx2_exec(char **argv)
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{
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char exe[PATH_MAX] = { 0 };
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const char *p;
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if (readlink("/proc/self/exe", exe, PATH_MAX - 1) < 0)
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die_perror("Failed to read own /proc/self/exe link");
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p = strstr(exe, ".avx2");
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if (p && strlen(p) == strlen(".avx2"))
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return;
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if (__builtin_cpu_supports("avx2")) {
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char new_path[PATH_MAX + sizeof(".avx2")];
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if (snprintf_check(new_path, PATH_MAX + sizeof(".avx2"),
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"%s.avx2", exe))
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die_perror("Can't build AVX2 executable path");
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execve(new_path, argv, environ);
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warn_perror("Can't run AVX2 build, using non-AVX2 version");
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}
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}
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#else
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void arch_avx2_exec(char **argv) { (void)argv; }
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#endif
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