From 41b9d436b2739cbe8bf9482b665d85d59d06bc0e Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Tue, 24 Apr 2018 17:50:01 +0200 Subject: [PATCH] mtd: some basic code cleanups MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit While looking at our exit() invocations I noticed that the mtd_probe stuff uses 'exit(-1)' at various places, which is not really a good idea, as exit codes of processes on Linux are supposed to be in the range of 0…255. This patch cleans that up a bit, and fixes a number of other things: 1. Let's always let main() exit, nothing intermediary. We generally don't like code that invokes exit() on its own. 2. Close the file descriptors opened. 3. Some logging for errors is added, mostly on debug level. Please review this with extra care. As I don't have the right hardware to test this patch I only did superficial testing. --- src/udev/mtd_probe/mtd_probe.c | 30 +++++++++++++------------ src/udev/mtd_probe/mtd_probe.h | 2 +- src/udev/mtd_probe/probe_smartmedia.c | 41 ++++++++++++++++++++--------------- 3 files changed, 40 insertions(+), 33 deletions(-) diff --git a/src/udev/mtd_probe/mtd_probe.c b/src/udev/mtd_probe/mtd_probe.c index 1d692f1..fa5f41f 100644 --- a/src/udev/mtd_probe/mtd_probe.c +++ b/src/udev/mtd_probe/mtd_probe.c @@ -18,6 +18,7 @@ * Boston, MA 02110-1301 USA */ +#include #include #include #include @@ -27,31 +28,32 @@ #include #include +#include "alloc-util.h" +#include "fd-util.h" #include "mtd_probe.h" -int main(int argc, char** argv) -{ - int mtd_fd; - int error; +int main(int argc, char** argv) { + _cleanup_close_ int mtd_fd = -1; mtd_info_t mtd_info; if (argc != 2) { printf("usage: mtd_probe /dev/mtd[n]\n"); - return 1; + return EXIT_FAILURE; } mtd_fd = open(argv[1], O_RDONLY|O_CLOEXEC); - if (mtd_fd == -1) { - perror("open"); - exit(-1); + if (mtd_fd < 0) { + log_error_errno(errno, "Failed to open: %m"); + return EXIT_FAILURE; } - error = ioctl(mtd_fd, MEMGETINFO, &mtd_info); - if (error == -1) { - perror("ioctl"); - exit(-1); + if (ioctl(mtd_fd, MEMGETINFO, &mtd_info) < 0) { + log_error_errno(errno, "Failed to issue MEMGETINFO ioctl: %m"); + return EXIT_FAILURE; } - probe_smart_media(mtd_fd, &mtd_info); - return -1; + if (probe_smart_media(mtd_fd, &mtd_info) < 0) + return EXIT_FAILURE; + + return EXIT_SUCCESS; } diff --git a/src/udev/mtd_probe/mtd_probe.h b/src/udev/mtd_probe/mtd_probe.h index 39841f9..20ff862 100644 --- a/src/udev/mtd_probe/mtd_probe.h +++ b/src/udev/mtd_probe/mtd_probe.h @@ -49,4 +49,4 @@ struct sm_oob { #define SM_SMALL_PAGE 256 #define SM_SMALL_OOB_SIZE 8 -void probe_smart_media(int mtd_fd, mtd_info_t *info); +int probe_smart_media(int mtd_fd, mtd_info_t *info); diff --git a/src/udev/mtd_probe/probe_smartmedia.c b/src/udev/mtd_probe/probe_smartmedia.c index c058d83..da937a3 100644 --- a/src/udev/mtd_probe/probe_smartmedia.c +++ b/src/udev/mtd_probe/probe_smartmedia.c @@ -18,6 +18,7 @@ * Boston, MA 02110-1301 USA */ +#include #include #include #include @@ -35,7 +36,7 @@ static const uint8_t cis_signature[] = { 0x01, 0x03, 0xD9, 0x01, 0xFF, 0x18, 0x02, 0xDF, 0x01, 0x20 }; -void probe_smart_media(int mtd_fd, mtd_info_t* info) { +int probe_smart_media(int mtd_fd, mtd_info_t* info) { int sector_size; int block_size; int size_in_megs; @@ -46,17 +47,21 @@ void probe_smart_media(int mtd_fd, mtd_info_t* info) { cis_buffer = malloc(SM_SECTOR_SIZE); if (!cis_buffer) - return; + return log_oom(); - if (info->type != MTD_NANDFLASH) - goto exit; + if (info->type != MTD_NANDFLASH) { + log_debug("Not marked MTD_NANDFLASH."); + return -EINVAL; + } sector_size = info->writesize; block_size = info->erasesize; size_in_megs = info->size / (1024 * 1024); - if (!IN_SET(sector_size, SM_SECTOR_SIZE, SM_SMALL_PAGE)) - goto exit; + if (!IN_SET(sector_size, SM_SECTOR_SIZE, SM_SMALL_PAGE)) { + log_debug("Unexpected sector size: %i", sector_size); + return -EINVAL; + } switch(size_in_megs) { case 1: @@ -71,26 +76,26 @@ void probe_smart_media(int mtd_fd, mtd_info_t* info) { break; } - for (offset = 0 ; offset < block_size * spare_count ; - offset += sector_size) { - lseek(mtd_fd, SEEK_SET, offset); + for (offset = 0; offset < block_size * spare_count; offset += sector_size) { + (void) lseek(mtd_fd, SEEK_SET, offset); + if (read(mtd_fd, cis_buffer, SM_SECTOR_SIZE) == SM_SECTOR_SIZE) { cis_found = 1; break; } } - if (!cis_found) - goto exit; + if (!cis_found) { + log_debug("CIS not found"); + return -EINVAL; + } if (memcmp(cis_buffer, cis_signature, sizeof(cis_signature)) != 0 && - (memcmp(cis_buffer + SM_SMALL_PAGE, cis_signature, - sizeof(cis_signature)) != 0)) - goto exit; + memcmp(cis_buffer + SM_SMALL_PAGE, cis_signature, sizeof(cis_signature)) != 0) { + log_debug("CIS signature didn't match"); + return -EINVAL; + } printf("MTD_FTL=smartmedia\n"); - exit(EXIT_SUCCESS); - -exit: - return; + return 0; } -- 2.7.4