From d95258ac4b268c09a2ee6d01cec7dcbe62bfc070 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Fri, 12 Dec 2025 08:01:53 +0100 Subject: [PATCH] ld/Linux: determine program name in a more reliable manner What argv[0] holds can be pretty arbitrary. As long as it's used for just diagnostics, that may be pretty okay to go from, but ld also uses it to find linker scripts. For that we want to be sure we start from the real executable name. Which on Linux we can determine from the /proc/self/exe symbolic link target (provided of course procfs is mounted). While there constify program_name as well. --- ld/ldmain.c | 17 +++++++++++++++-- ld/ldmain.h | 2 +- 2 files changed, 16 insertions(+), 3 deletions(-) diff --git a/ld/ldmain.c b/ld/ldmain.c index 157f205671e..afffdd2e43d 100644 --- a/ld/ldmain.c +++ b/ld/ldmain.c @@ -67,7 +67,7 @@ char *default_target; const char *output_filename = "a.out"; /* Name this program was invoked by. */ -char *program_name; +const char *program_name; /* The prefix for system library directories. */ const char *ld_sysroot; @@ -567,6 +567,19 @@ report_phases (FILE * file, time_t * start, char ** argv) fflush (file); } +static void +set_program_name (const char *argv0) +{ + program_name = argv0; + +#if defined (__linux__) && _POSIX_VERSION >= 200112L + char name[PATH_MAX]; + ssize_t len = readlink ("/proc/self/exe", name, ARRAY_SIZE (name)); + if (len > 0 && (size_t)len < ARRAY_SIZE (name)) + program_name = xmemdup (name, len, len + 1); +#endif +} + int main (int argc, char **argv) { @@ -581,7 +594,7 @@ main (int argc, char **argv) bindtextdomain (PACKAGE, LOCALEDIR); textdomain (PACKAGE); - program_name = argv[0]; + set_program_name (argv[0]); xmalloc_set_program_name (program_name); /* Check the LD_STATS environment variable before parsing the command line diff --git a/ld/ldmain.h b/ld/ldmain.h index 0baa3c305c3..ec33b496f86 100644 --- a/ld/ldmain.h +++ b/ld/ldmain.h @@ -21,7 +21,7 @@ #ifndef LDMAIN_H #define LDMAIN_H -extern char *program_name; +extern const char *program_name; extern const char *ld_sysroot; extern char *ld_canon_sysroot; extern int ld_canon_sysroot_len; -- 2.47.3