From 741d78126b5584e860811c78f87f51597e375592 Mon Sep 17 00:00:00 2001 From: Konstantin Belousov Date: Sat, 2 Jan 2021 00:24:46 +0200 Subject: rtld: call close(2) after errno is saved MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit to prevent obliteration of error value from the original syscall. Also improve error message for short read. Submitted by: Konrad Sewiłło-Jopek MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D27864 --- libexec/rtld-elf/libmap.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/libexec/rtld-elf/libmap.c b/libexec/rtld-elf/libmap.c index 8057a0ccf43d..499d2cd2a1d9 100644 --- a/libexec/rtld-elf/libmap.c +++ b/libexec/rtld-elf/libmap.c @@ -103,7 +103,7 @@ lmc_parse_file(const char *path) char *lm_map; struct stat st; ssize_t retval; - int fd; + int fd, saved_errno; TAILQ_FOREACH(p, &lmc_head, next) { if (strcmp(p->path, path) == 0) @@ -117,9 +117,9 @@ lmc_parse_file(const char *path) return; } if (fstat(fd, &st) == -1) { - close(fd); dbg("lm_parse_file: fstat(\"%s\") failed, %s", path, rtld_strerror(errno)); + close(fd); return; } @@ -132,14 +132,19 @@ lmc_parse_file(const char *path) lm_map = xmalloc(st.st_size); retval = read(fd, lm_map, st.st_size); + saved_errno = errno; + close(fd); if (retval != st.st_size) { - close(fd); + if (retval == -1) { + dbg("lm_parse_file: read(\"%s\") failed, %s", path, + rtld_strerror(saved_errno)); + } else { + dbg("lm_parse_file: short read(\"%s\"), %zd vs %jd", + path, retval, (uintmax_t)st.st_size); + } free(lm_map); - dbg("lm_parse_file: read(\"%s\") failed, %s", path, - rtld_strerror(errno)); return; } - close(fd); p = xmalloc(sizeof(struct lmc)); p->path = xstrdup(path); p->dev = st.st_dev; -- cgit v1.2.3