diff options
| author | Leah Rowe <leah@libreboot.org> | 2026-03-10 14:25:43 +0000 |
|---|---|---|
| committer | Leah Rowe <leah@libreboot.org> | 2026-03-10 14:25:43 +0000 |
| commit | 4bc7ba1e4b95ac9f1501401fee97bdab7fbf475c (patch) | |
| tree | 972e6125a1b4d0745bf935cb1c2e970ef60d9544 | |
| parent | c953228bb002059faa92b9e000303099d80b9091 (diff) | |
util/nvmutil: use O_NONBLOCK on /dev/[u]random
on some systems, it is otherwise blocking, but blocking
can be disabled, making access more reliable.
Signed-off-by: Leah Rowe <leah@libreboot.org>
| -rw-r--r-- | util/nvmutil/nvmutil.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/util/nvmutil/nvmutil.c b/util/nvmutil/nvmutil.c index 0101888e..d5f0c2b1 100644 --- a/util/nvmutil/nvmutil.c +++ b/util/nvmutil/nvmutil.c @@ -101,6 +101,10 @@ typedef char static_assert_off_t_is_32[(sizeof(off_t) >= 4) ? 1 : -1]; #define O_BINARY 0 #endif +#ifndef O_NONBLOCK +#define O_NONBLOCK 0 +#endif + /* * Sanitize command tables. */ @@ -708,11 +712,15 @@ static void open_dev_urandom(void) { rname = newrandom; - if ((urandom_fd = open(rname, O_RDONLY | O_BINARY)) != -1) + urandom_fd = open(rname, O_RDONLY | O_BINARY | O_NONBLOCK); + if (urandom_fd != -1) return; /* * Fall back to /dev/random on very old Unix. + * + * We must reset errno, to remove stale state + * set by reading /dev/urandom */ fprintf(stderr, "Can't open %s (will use %s instead)\n", @@ -721,7 +729,7 @@ open_dev_urandom(void) errno = 0; rname = oldrandom; - xopen(&urandom_fd, rname, O_RDONLY | O_BINARY, &gbe_st); + xopen(&urandom_fd, rname, O_RDONLY | O_BINARY | O_NONBLOCK, &gbe_st); } static void |