From 17689cc9bf52feb5d31fdbf279f6137f1d6446cb Mon Sep 17 00:00:00 2001 From: Stefano Brivio Date: Wed, 13 Jul 2022 03:20:45 +0200 Subject: arch, passt: Use executable link to form AVX2 binary path ...instead of argv[0], which might or might not contain a valid path to the executable itself. Instead of mangling argv[0], use the same link to find out if we're already running the AVX2 build where supported. Alternatively, we could use execvpe(), but that might result in running a different installed version, in case e.g. the set of binaries is present in both /usr/bin and /usr/local/bin, with both being in $PATH. Reported-by: Wenli Quan Link: https://bugzilla.redhat.com/show_bug.cgi?id=2101310 Signed-off-by: Stefano Brivio --- arch.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) (limited to 'arch.c') diff --git a/arch.c b/arch.c index ae21d59..10eb24a 100644 --- a/arch.c +++ b/arch.c @@ -14,26 +14,31 @@ #include #include +#include #include #include /** - * arch_avx2_exec() - Run AVX2 build if supported, drop suffix from argv[0] + * arch_avx2_exec() - Switch to AVX2 build if supported * @argv: Arguments from command line */ #ifdef __x86_64__ -static char avx2_path[PATH_MAX]; - void arch_avx2_exec(char **argv) { - char *p = strstr(argv[0], ".avx2"); + char exe[PATH_MAX] = { 0 }, new_path[PATH_MAX + sizeof(".avx2")], *p; + + if (readlink("/proc/self/exe", exe, PATH_MAX - 1) < 0) { + perror("readlink /proc/self/exe"); + exit(EXIT_FAILURE); + } + + p = strstr(exe, ".avx2"); + if (p && strlen(p) == strlen(".avx2")) + return; - if (p) { - *p = 0; - } else if (__builtin_cpu_supports("avx2")) { - snprintf(avx2_path, PATH_MAX, "%s.avx2", argv[0]); - argv[0] = avx2_path; - execve(avx2_path, argv, environ); + if (__builtin_cpu_supports("avx2")) { + snprintf(new_path, PATH_MAX + sizeof(".avx2"), "%s.avx2", exe); + execve(new_path, argv, environ); perror("Can't run AVX2 build, using non-AVX2 version"); } } -- cgit v1.2.3