diff options
| author | Leah Rowe <leah@libreboot.org> | 2026-03-14 21:21:31 +0000 |
|---|---|---|
| committer | Leah Rowe <leah@libreboot.org> | 2026-03-14 21:25:24 +0000 |
| commit | 74d26d446e9cf31dd80e893b4c47dc438334df1b (patch) | |
| tree | 717a96a2143a8c5a5510cc538ee5da4a880d6bce /util | |
| parent | 6bc7efe675e7bd6112a6df7eb68bdfebceaf5694 (diff) | |
util/nvmutil: move looping logic to rw_file_exact
rw_file_once was doing what rw_file_exact should be
doing
_once does what it says: once
we were passing an offset (rc) to it that it was not
meaningfully using.
this makes the code now more robust, especially if
we later swap out or break _once - then we don't
get weird behaviour (if there is a regression).
Signed-off-by: Leah Rowe <leah@libreboot.org>
Diffstat (limited to 'util')
| -rw-r--r-- | util/nvmutil/nvmutil.c | 35 |
1 files changed, 20 insertions, 15 deletions
diff --git a/util/nvmutil/nvmutil.c b/util/nvmutil/nvmutil.c index 37d51515..ba4ee1e3 100644 --- a/util/nvmutil/nvmutil.c +++ b/util/nvmutil/nvmutil.c @@ -411,7 +411,7 @@ static ssize_t rw_file_once(int fd, u8 *mem, size_t len, static ssize_t prw(int fd, void *mem, size_t nrw, off_t off, int rw_type, int loop_eagain, int loop_eintr); static int check_file(int fd, struct stat *st); -static int rw_over_nrw(ssize_t r, size_t nrw); +static ssize_t rw_over_nrw(ssize_t r, size_t nrw); static off_t lseek_loop(int fd, off_t off, int whence, int loop_eagain, int loop_eintr); static int try_err(int loop_err, int errval); @@ -1874,32 +1874,37 @@ rw_file_exact(int fd, u8 *mem, size_t nrw, int loop_eintr, size_t max_retries) { ssize_t rv = 0; - size_t rc = 0; + ssize_t rc = 0; + size_t retries_on_zero = 0; - for (rc = 0, rv = 0; rc < nrw; ) { + while (1) { - rc += (size_t)rv; + rc += rv; + if ((size_t)rc >= nrw) + break; if ((rv = rw_file_once(fd, mem + rc, nrw - rc, off + rc, rw_type, loop_eagain, loop_eintr, max_retries)) < 0) return -1; - /* rw_file_once never returns - zero, but it's still logically - incorrect not to handle it here */ - + /* Prevent theoretical overflow */ + if ((size_t)rv > (nrw - rc)) + goto err_rw_file_exact; + if (rv == 0) { - errno = EIO; - return -1; + if (retries_on_zero++ < max_retries) + continue; + goto err_rw_file_exact; } - /* Prevent theoretical overflow */ - if ((size_t)rv > nrw - rc) - goto err_rw_file_exact; + retries_on_zero = 0; } - return rc; + if ((size_t)rc != nrw) + goto err_rw_file_exact; + + return rw_over_nrw(rc, nrw); err_rw_file_exact: errno = EIO; @@ -2113,7 +2118,7 @@ err_is_file: * POSIX can say whatever it wants. * specification != implementation */ -static int +static ssize_t rw_over_nrw(ssize_t r, size_t nrw) { if (r == -1) |