splatink/lbmk
1
0
Fork 0
mirror of https://codeberg.org/libreboot/lbmk.git synced 2026-03-25 13:29:03 +02:00
Code Issues Packages Projects Releases Wiki Activity

nvmutil: toggle for fd thread-safety err state

Browse Source 
Signed-off-by: Leah Rowe <leah@libreboot.org>
This commit is contained in:
Leah Rowe
2026-03-14 22:38:56 +00:00
parent 0a4257f4ed
commit 93603e1572
1 changed files with 35 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

40
util/nvmutil/nvmutil.c
View File

@@ -15,6 +15,11 @@
* -Os -Wall -Wextra -Werror -pedantic -std=c90
*/
#define OFF_ERR 0
#ifndef OFF_RESET
#define OFF_RESET 1
#endif
/*
* NOTE: older Linux lacked arc4random.
* added in glibc 2.36. Just pass HAVE_ARC4RANDOM_BUF=0
@@ -409,7 +414,8 @@ static ssize_t rw_file_exact(int fd, u8 *mem, size_t len,
off_t off, int rw_type, int loop_eagain, int loop_eintr,
size_t max_retries);
static ssize_t prw(int fd, void *mem, size_t nrw,
off_t off, int rw_type, int loop_eagain, int loop_eintr);
off_t off, int rw_type, int loop_eagain, int loop_eintr,
int off_reset);
static int check_file(int fd, struct stat *st);
static ssize_t rw_over_nrw(ssize_t r, size_t nrw);
#if !defined(HAVE_REAL_PREAD_PWRITE) || \
@@ -668,6 +674,8 @@ typedef char bool_loop_eintr[(LOOP_EINTR==1||LOOP_EINTR==0)?1:-1];
typedef char bool_loop_eagain[(LOOP_EAGAIN==1||LOOP_EAGAIN==0)?1:-1];
typedef char bool_no_loop_eintr[(NO_LOOP_EINTR==0)?1:-1];
typedef char bool_no_loop_eagain[(NO_LOOP_EAGAIN==0)?1:-1];
typedef char bool_off_err[(OFF_ERR==0)?1:-1];
typedef char bool_off_reset[(OFF_RESET==0||OFF_RESET==1)?1:-1];
static int io_err_gbe = 0;
static int rw_check_err_read[] = {0, 0};
@@ -1883,7 +1891,8 @@ rw_file_exact(int fd, u8 *mem, size_t nrw,
mem + (size_t)rc,
nrw - (size_t)rc,
off + (off_t)rc,
rw_type, loop_eagain, loop_eintr);
rw_type, loop_eagain, loop_eintr,
OFF_ERR);
if (rv < 0)
return -1;
@@ -1941,12 +1950,23 @@ err_rw_file_exact:
* NOTE: If you use loop_eagain (1), you enable wait
* loop on EAGAIN. Beware if using this on a non-blocking
* pipe (it could spin indefinitely).
*
* off_reset: if zero, and using fallback pwrite/pread
* analogs, we check if a file offset changed,
* which would indicate another thread changed
* it, and return error, without resetting the
* file - this would allow that thread to keep
* running, but we could then cause a whole
* program exit if we wanted to.
* if not zero:
* we reset and continue, and pray for the worst.
*/
static ssize_t
prw(int fd, void *mem, size_t nrw,
off_t off, int rw_type,
int loop_eagain, int loop_eintr)
int loop_eagain, int loop_eintr,
int off_reset)
{
ssize_t r;
int positional_rw;
@@ -2050,9 +2070,19 @@ real_pread_pwrite:
* Failure is the better option
* here, since recovery would
* mask hidden bugs in code.
* We cannot guarantee thread
* safety, except in the event
* that violations cause exit;
* you would then debug it.
*/
if (off != verified)
goto err_prw;
if (off != verified) {
if (!off_reset)
goto err_prw;
if (lseek_loop(fd, off, SEEK_SET,
loop_eagain, loop_eintr) == (off_t)-1)
return -1;
}
do {
if (rw_type == IO_PREAD)