allow specifying argv[0] when invoking a program via ldso command

previously, the pathname used to load the program was always used as
argv[0]. the default remains the same, but a new --argv0 option can be
used to provide a different value.

diff --git a/ldso/dynlink.c b/ldso/dynlink.c
index fc6a68b..35a90ae 100644 (file)
--- a/ldso/dynlink.c
+++ b/ldso/dynlink.c
@@ -1437,6 +1437,7 @@ _Noreturn void __dls3(size_t *sp)
        size_t aux[AUX_CNT], *auxv;
        size_t i;
        char *env_preload=0;
+       char *replace_argv0=0;
        size_t vdso_base;
        int argc = *sp;
        char **argv = (void *)(sp+1);
@@ -1521,6 +1522,10 @@ _Noreturn void __dls3(size_t *sp)
                                if (opt[7]=='=') env_preload = opt+8;
                                else if (opt[7]) *argv = 0;
                                else if (*argv) env_preload = *argv++;
+                       } else if (!memcmp(opt, "argv0", 5)) {
+                               if (opt[5]=='=') replace_argv0 = opt+6;
+                               else if (opt[5]) *argv = 0;
+                               else if (*argv) replace_argv0 = *argv++;
                        } else {
                                argv[0] = 0;
                        }
@@ -1677,6 +1682,8 @@ _Noreturn void __dls3(size_t *sp)
        debug.state = 0;
        _dl_debug_state();
 
+       if (replace_argv0) argv[0] = replace_argv0;
+
        errno = 0;
 
        CRTJMP((void *)aux[AT_ENTRY], argv-1);