From d2abde53033d58b6665becd75f854ad87aba33f6 Mon Sep 17 00:00:00 2001 From: Leah Rowe Date: Tue, 31 Mar 2026 15:43:43 +0100 Subject: libreboot-utils: stricter errno handling where possible, try not to clobber sys errno. override it only when relatively safe. also: when a syscall succeeds, it may set errno. this is rare, but permitted (nothing specified against it in specs, and the specs say that errno is undefined on success). i'm not libc, but i'm wrapping around it, so i need to be careful in how i handle the errno value. also: i removed the requirement for directories to be executable, in mkhtemp.c, because this isn't required and will only break certain setups. in world_writeable and sticky, i made the checks stricter: the faccessat check was being skipped on some paths, so i've closed that loophole now. i also generally cleaned up some code, as part of the errno handling refactoring, where it made sense to do so, plus a few other bits of code cleanup. Signed-off-by: Leah Rowe --- util/libreboot-utils/lib/rand.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'util/libreboot-utils/lib/rand.c') diff --git a/util/libreboot-utils/lib/rand.c b/util/libreboot-utils/lib/rand.c index 20dc33cd..adfad3d7 100644 --- a/util/libreboot-utils/lib/rand.c +++ b/util/libreboot-utils/lib/rand.c @@ -127,6 +127,7 @@ void rset(void *buf, size_t n) { int saved_errno = errno; + errno = 0; if (if_err(buf == NULL, EFAULT)) goto err; @@ -140,7 +141,6 @@ rset(void *buf, size_t n) ((USE_URANDOM) > 0)) arc4random_buf(buf, n); - goto out; #else size_t off = 0; @@ -166,7 +166,7 @@ retry_rand: #endif if (rc < 0) - goto err; + goto err; /* syscall fehler */ if (rc == 0) goto err; /* prevent infinite loop on fatal err */ @@ -180,16 +180,15 @@ retry_rand: #endif #endif -out: - errno = saved_errno; + reset_caller_errno(0); return; err: #if defined(USE_URANDOM) && \ ((USE_URANDOM) > 0) close_on_eintr(&fd); #endif - err_exit(ECANCELED, - "Randomisation failure, possibly unsupported in your kernel"); + (void) with_fallback_errno(ECANCELED); + err_exit(errno, "Randomisierungsfehler"); exit(EXIT_FAILURE); } #endif -- cgit v1.2.1