diff options
| -rw-r--r-- | util/nvmutil/nvmutil.c | 36 |
1 files changed, 28 insertions, 8 deletions
diff --git a/util/nvmutil/nvmutil.c b/util/nvmutil/nvmutil.c index 32fafa59..27aa1354 100644 --- a/util/nvmutil/nvmutil.c +++ b/util/nvmutil/nvmutil.c @@ -89,7 +89,7 @@ static void set_mac_nib(size_t mac_str_pos, size_t mac_byte_pos, size_t mac_nib_pos); static uint16_t hextonum(char ch_s); static uint16_t rhex(void); -static void read_file_exact(int fd, void *buf, size_t len, +static ssize_t read_gbe_file_exact(int fd, void *buf, size_t len, off_t off, const char *path, const char *op); static void write_mac_part(size_t partnum); static void cmd_helper_dump(void); @@ -691,8 +691,10 @@ read_gbe_file_part(size_t p) void *mem_offset = gbe_mem_offset(p ^ command[cmd_index].invert, "pread"); - read_file_exact(gbe_fd, mem_offset, - gbe_rw_size, gbe_file_offset(p, "pread"), fname, "pread"); + if ((size_t)read_gbe_file_exact(gbe_fd, mem_offset, + gbe_rw_size, gbe_file_offset(p, "pread"), fname, "pread") != + gbe_rw_size) + err(ECANCELED, "Partial read p%zu, file %s", p, fname); printf("Read %zu bytes from part %zu: %s\n", gbe_rw_size, p, fname); @@ -913,15 +915,16 @@ rhex(void) #ifdef NVMUTIL_ARC4RANDOM_BUF arc4random_buf(rnum, n); #else - read_file_exact(urandom_fd, rnum, n, 0, rname, NULL); + n = (size_t)read_gbe_file_exact(urandom_fd, + rnum, n, 0, rname, NULL); #endif } return (uint16_t)(rnum[--n] & 0xf); } -static void -read_file_exact(int fd, void *buf, size_t len, +static ssize_t +read_gbe_file_exact(int fd, void *buf, size_t len, off_t off, const char *path, const char *op) { int retry; @@ -938,13 +941,29 @@ read_file_exact(int fd, void *buf, size_t len, if (rval == (ssize_t)len) { errno = 0; - return; + return rval; } - if (rval != -1) + if (rval != -1) { + if (path == oldrandom || path == newrandom) { + /* + * /dev/[u]random reads can still return + * partial reads legally, on some weird + * Unix systems (especially older ones). + * + * We use a circular buffer for random + * bytes in rhex(), so we can just use + * the smaller amount of bytes and call + * read_gbe_file_exact again if necessary. + */ + if (rval > 0) + return rval; + } + err(ECANCELED, "Short %s, %zd bytes, on file: %s", op ? op : "read", rval, path); + } if (errno != EINTR) err(ECANCELED, @@ -954,6 +973,7 @@ read_file_exact(int fd, void *buf, size_t len, err(EINTR, "%s: max retries exceeded on file: %s", op ? op : "read", path); + return -1; } static void |