From 1b50ff64a52b08bebb17d947eb95c18ba88fa20f Mon Sep 17 00:00:00 2001 From: Warner Losh Date: Thu, 29 Apr 2021 19:34:34 -0600 Subject: bsd-user: implement path searching Use the PATH to find the executable given a bare argument. We need to do this so we can implement mixing native and emulated binaries (e.g., execing a x86 native binary from an emulated arm binary to optimize parts of the build). By finding the binary, we will know how to exec it. Signed-off-by: Stacey Son Signed-off-by: Warner Losh Reviewed-by: Richard Henderson --- bsd-user/bsdload.c | 36 +++++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) (limited to 'bsd-user/bsdload.c') diff --git a/bsd-user/bsdload.c b/bsd-user/bsdload.c index 379015c744..32f7fd5dec 100644 --- a/bsd-user/bsdload.c +++ b/bsd-user/bsdload.c @@ -139,21 +139,55 @@ abi_ulong loader_build_argptr(int envc, int argc, abi_ulong sp, return sp; } +static bool is_there(const char *candidate) +{ + struct stat fin; + + /* XXX work around access(2) false positives for superuser */ + if (access(candidate, X_OK) == 0 && stat(candidate, &fin) == 0 && + S_ISREG(fin.st_mode) && (getuid() != 0 || + (fin.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) != 0)) { + return true; + } + + return false; +} + int loader_exec(const char *filename, char **argv, char **envp, struct target_pt_regs *regs, struct image_info *infop, struct bsd_binprm *bprm) { + char *path, fullpath[PATH_MAX]; int retval, i; bprm->p = TARGET_PAGE_SIZE * MAX_ARG_PAGES; for (i = 0; i < MAX_ARG_PAGES; i++) { /* clear page-table */ bprm->page[i] = NULL; } - retval = open(filename, O_RDONLY); + + if (strchr(filename, '/') != NULL) { + path = realpath(filename, fullpath); + if (path == NULL) { + /* Failed to resolve. */ + return -1; + } + if (!is_there(path)) { + return -1; + } + } else { + path = g_find_program_in_path(filename); + if (path == NULL) { + return -1; + } + } + + retval = open(path, O_RDONLY); if (retval < 0) { + g_free(path); return retval; } + bprm->fullpath = path; bprm->fd = retval; bprm->filename = (char *)filename; bprm->argc = count(argv); -- cgit 1.4.1