[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-4.1-testing] blktap2: Fix naked unchecked uses of read/write/chdir.
# HG changeset patch # User Keir Fraser <keir@xxxxxxx> # Date 1337011152 -3600 # Node ID 35248be669e71520eb40e85986b106bd5164d7ea # Parent 89c61e66f45f8ca3c8e96b1d348088f0caa12e73 blktap2: Fix naked unchecked uses of read/write/chdir. These cause warnings under warn_unused_result, and for read/write we ought to deal with partial io results. Signed-off-by: Keir Fraser <keir@xxxxxxx> xen-unstable changeset: 25299:01d64a3dea71 xen-unstable date: Fri May 11 18:30:29 2012 +0100 blktap2: Fix another uninitialised value error gcc -O1 -fno-omit-frame-pointer -m32 -march=i686 -g -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wdeclaration-after-statement -D__XEN_TOOLS__ -MMD -MF .block-remus.o.d -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -fno-optimize-sibling-calls -mno-tls-direct-seg-refs -Werror -g -Wno-unused -fno-strict-aliasing -I../include -I../drivers -I/home/osstest/build.12828.build-i386/xen-unstable/tools/blktap2/drivers/../../../tools/libxc -I/home/osstest/build.12828.build-i386/xen-unstable/tools/blktap2/drivers/../../../tools/include -D_GNU_SOURCE -DUSE_NFS_LOCKS -c -o block-remus.o block-remus.c block-remus.c: In function 'ramdisk_flush': block-remus.c:508: error: 'buf' may be used uninitialized in this function make[5]: *** [block-remus.o] Error 1 This is because gcc can see that merge_requests doesn't always set *mergedbuf but gcc isn't able to prove that it always does so if merge_requests returns 0 and that in that case the value of ramdisk_flush::buf isn't used. This is too useful a warning to disable, despite the occasional false positive of this form. The conventional approach is to suppress the warning by explicitly initialising the variable to 0. This has just come to light because 25275:27d63b9f111a reenabled optimisation for this area of code, and gcc's data flow analysis (which is required to trigger the uninitialised variable warning) only occurs when optimisation is turned on. Signed-off-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx> xen-unstable changeset: 25281:60064411a8a9 xen-unstable date: Thu May 10 14:26:14 2012 +0100 blktap2: Do not build with -O0 Signed-off-by: Keir Fraser <keir@xxxxxxx> xen-unstable changeset: 25275:27d63b9f111a xen-unstable date: Thu May 10 11:22:18 2012 +0100 blktap2: Fix uninitialised value error. Signed-off-by: Keir Fraser <keir@xxxxxxx> xen-unstable changeset: 25274:cb82b5aa73bd xen-unstable date: Thu May 10 11:21:59 2012 +0100 tools/blktap2: fix out of bounds access in block-log.c block-log.c: In function 'ctl_close_sock': block-log.c:363:23: warning: array subscript is above array bounds [-Warray-bounds] Adjust loop condition in ctl_close_sock() to fix warning. Adjust array acccess in ctl_close() to actually access the array member. Signed-off-by: Olaf Hering <olaf@xxxxxxxxx> Acked-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx> Committed-by: Keir Fraser <keir@xxxxxxx> xen-unstable changeset: 25273:83a02f225bde xen-unstable date: Thu May 10 11:20:04 2012 +0100 tools/blktap2: fix build errors caused by Werror in vhd_journal_write_entry -O2 -Wall -Werror triggers these warnings: libvhd-journal.c: In function 'vhd_journal_write_entry': libvhd-journal.c:335: warning: statement with no effect Really return the error from vhd_journal_write() to caller. v2: - simplify the patch by just adding the missing return statement Signed-off-by: Olaf Hering <olaf@xxxxxxxxx> Committed-by: Keir Fraser <keir@xxxxxxx> xen-unstable changeset: 25272:ca02580986d2 xen-unstable date: Thu May 10 11:19:05 2012 +0100 --- diff -r 89c61e66f45f -r 35248be669e7 tools/blktap2/drivers/Makefile --- a/tools/blktap2/drivers/Makefile Mon May 14 16:51:27 2012 +0100 +++ b/tools/blktap2/drivers/Makefile Mon May 14 16:59:12 2012 +0100 @@ -9,7 +9,7 @@ QCOW_UTIL = img2qcow qcow-create qcow2r LOCK_UTIL = lock-util INST_DIR = $(SBINDIR) -CFLAGS += -Werror -g -O0 +CFLAGS += -Werror -g CFLAGS += -Wno-unused CFLAGS += -fno-strict-aliasing CFLAGS += -I$(BLKTAP_ROOT)/include -I$(BLKTAP_ROOT)/drivers diff -r 89c61e66f45f -r 35248be669e7 tools/blktap2/drivers/block-log.c --- a/tools/blktap2/drivers/block-log.c Mon May 14 16:51:27 2012 +0100 +++ b/tools/blktap2/drivers/block-log.c Mon May 14 16:59:12 2012 +0100 @@ -347,11 +347,11 @@ static int ctl_open(struct tdlog_state* static int ctl_close(struct tdlog_state* s) { while (s->connected) { + s->connected--; tapdisk_server_unregister_event(s->connections[s->connected].id); close(s->connections[s->connected].fd); s->connections[s->connected].fd = -1; s->connections[s->connected].id = 0; - s->connected--; } if (s->ctl.fd >= 0) { @@ -382,7 +382,7 @@ static int ctl_close_sock(struct tdlog_s { int i; - for (i = 0; i <= s->connected; i++) { + for (i = 0; i < s->connected; i++) { if (s->connections[i].fd == fd) { tapdisk_server_unregister_event(s->connections[i].id); close(s->connections[i].fd); diff -r 89c61e66f45f -r 35248be669e7 tools/blktap2/drivers/block-qcow.c --- a/tools/blktap2/drivers/block-qcow.c Mon May 14 16:51:27 2012 +0100 +++ b/tools/blktap2/drivers/block-qcow.c Mon May 14 16:59:12 2012 +0100 @@ -1428,7 +1428,7 @@ int tdqcow_get_parent_id(td_driver_t *dr { off_t off; char *buf, *filename; - int len, secs, type, err = -EINVAL; + int len, secs, type = 0, err = -EINVAL; struct tdqcow_state *child = (struct tdqcow_state *)driver->data; if (!child->backing_file_offset) diff -r 89c61e66f45f -r 35248be669e7 tools/blktap2/drivers/block-remus.c --- a/tools/blktap2/drivers/block-remus.c Mon May 14 16:51:27 2012 +0100 +++ b/tools/blktap2/drivers/block-remus.c Mon May 14 16:59:12 2012 +0100 @@ -505,7 +505,7 @@ fail: static int ramdisk_flush(td_driver_t *driver, struct tdremus_state* s) { uint64_t* sectors; - char* buf; + char* buf = NULL; uint64_t base, batchlen; int i, j, count = 0; diff -r 89c61e66f45f -r 35248be669e7 tools/blktap2/drivers/tapdisk-diff.c --- a/tools/blktap2/drivers/tapdisk-diff.c Mon May 14 16:51:27 2012 +0100 +++ b/tools/blktap2/drivers/tapdisk-diff.c Mon May 14 16:59:12 2012 +0100 @@ -39,6 +39,7 @@ #include "tapdisk-vbd.h" #include "tapdisk-server.h" #include "tapdisk-disktype.h" +#include "tapdisk-utils.h" #include "libvhd.h" #define POLL_READ 0 @@ -170,7 +171,7 @@ tapdisk_stream_poll_clear(struct tapdisk { int dummy; - read(p->pipe[POLL_READ], &dummy, sizeof(dummy)); + read_exact(p->pipe[POLL_READ], &dummy, sizeof(dummy)); p->set = 0; } @@ -180,7 +181,7 @@ tapdisk_stream_poll_set(struct tapdisk_s int dummy = 0; if (!p->set) { - write(p->pipe[POLL_WRITE], &dummy, sizeof(dummy)); + write_exact(p->pipe[POLL_WRITE], &dummy, sizeof(dummy)); p->set = 1; } } diff -r 89c61e66f45f -r 35248be669e7 tools/blktap2/drivers/tapdisk-log.c --- a/tools/blktap2/drivers/tapdisk-log.c Mon May 14 16:51:27 2012 +0100 +++ b/tools/blktap2/drivers/tapdisk-log.c Mon May 14 16:59:12 2012 +0100 @@ -37,6 +37,7 @@ #include <sys/time.h> #include "tapdisk-log.h" +#include "tapdisk-utils.h" #define MAX_ENTRY_LEN 512 #define MAX_ERROR_MESSAGES 16 @@ -247,7 +248,7 @@ tlog_flush(void) wsize = ((size + 511) & (~511)); memset(tapdisk_log.buf + size, '\n', wsize - size); - write(fd, tapdisk_log.buf, wsize); + write_exact(fd, tapdisk_log.buf, wsize); tapdisk_log.p = tapdisk_log.buf; diff -r 89c61e66f45f -r 35248be669e7 tools/blktap2/drivers/tapdisk-queue.c --- a/tools/blktap2/drivers/tapdisk-queue.c Mon May 14 16:51:27 2012 +0100 +++ b/tools/blktap2/drivers/tapdisk-queue.c Mon May 14 16:59:12 2012 +0100 @@ -435,7 +435,7 @@ tapdisk_lio_ack_event(struct tqueue *que uint64_t val; if (lio->flags & LIO_FLAG_EVENTFD) - read(lio->event_fd, &val, sizeof(val)); + read_exact(lio->event_fd, &val, sizeof(val)); } static void diff -r 89c61e66f45f -r 35248be669e7 tools/blktap2/drivers/tapdisk-stream.c --- a/tools/blktap2/drivers/tapdisk-stream.c Mon May 14 16:51:27 2012 +0100 +++ b/tools/blktap2/drivers/tapdisk-stream.c Mon May 14 16:59:12 2012 +0100 @@ -38,6 +38,7 @@ #include "tapdisk-vbd.h" #include "tapdisk-server.h" #include "tapdisk-disktype.h" +#include "tapdisk-utils.h" #define POLL_READ 0 #define POLL_WRITE 1 @@ -145,7 +146,7 @@ tapdisk_stream_poll_clear(struct tapdisk { int dummy; - read(p->pipe[POLL_READ], &dummy, sizeof(dummy)); + read_exact(p->pipe[POLL_READ], &dummy, sizeof(dummy)); p->set = 0; } @@ -155,7 +156,7 @@ tapdisk_stream_poll_set(struct tapdisk_s int dummy = 0; if (!p->set) { - write(p->pipe[POLL_WRITE], &dummy, sizeof(dummy)); + write_exact(p->pipe[POLL_WRITE], &dummy, sizeof(dummy)); p->set = 1; } } @@ -203,7 +204,7 @@ tapdisk_stream_print_request(struct tapd { unsigned long idx = (unsigned long)tapdisk_stream_request_idx(s, sreq); char *buf = (char *)MMAP_VADDR(s->vbd->ring.vstart, idx, 0); - write(s->out_fd, buf, sreq->secs << SECTOR_SHIFT); + write_exact(s->out_fd, buf, sreq->secs << SECTOR_SHIFT); } static void diff -r 89c61e66f45f -r 35248be669e7 tools/blktap2/drivers/tapdisk-utils.c --- a/tools/blktap2/drivers/tapdisk-utils.c Mon May 14 16:51:27 2012 +0100 +++ b/tools/blktap2/drivers/tapdisk-utils.c Mon May 14 16:59:12 2012 +0100 @@ -175,3 +175,40 @@ int tapdisk_linux_version(void) } #endif +int read_exact(int fd, void *data, size_t size) +{ + size_t offset = 0; + ssize_t len; + + while ( offset < size ) + { + len = read(fd, (char *)data + offset, size - offset); + if ( (len == -1) && (errno == EINTR) ) + continue; + if ( len == 0 ) + errno = 0; + if ( len <= 0 ) + return -1; + offset += len; + } + + return 0; +} + +int write_exact(int fd, const void *data, size_t size) +{ + size_t offset = 0; + ssize_t len; + + while ( offset < size ) + { + len = write(fd, (const char *)data + offset, size - offset); + if ( (len == -1) && (errno == EINTR) ) + continue; + if ( len <= 0 ) + return -1; + offset += len; + } + + return 0; +} diff -r 89c61e66f45f -r 35248be669e7 tools/blktap2/drivers/tapdisk-utils.h --- a/tools/blktap2/drivers/tapdisk-utils.h Mon May 14 16:51:27 2012 +0100 +++ b/tools/blktap2/drivers/tapdisk-utils.h Mon May 14 16:59:12 2012 +0100 @@ -39,4 +39,7 @@ int tapdisk_namedup(char **, const char int tapdisk_get_image_size(int, uint64_t *, uint32_t *); int tapdisk_linux_version(void); +int read_exact(int fd, void *data, size_t size); /* EOF => -1, errno=0 */ +int write_exact(int fd, const void *data, size_t size); + #endif diff -r 89c61e66f45f -r 35248be669e7 tools/blktap2/drivers/tapdisk2.c --- a/tools/blktap2/drivers/tapdisk2.c Mon May 14 16:51:27 2012 +0100 +++ b/tools/blktap2/drivers/tapdisk2.c Mon May 14 16:59:12 2012 +0100 @@ -79,7 +79,12 @@ main(int argc, char *argv[]) if (optind != argc) usage(argv[0], EINVAL); - chdir("/"); + if (chdir("/")) { + DPRINTF("failed to chdir(/): %d\n", errno); + err = 1; + goto out; + } + tapdisk_start_logging("tapdisk2"); err = tapdisk_server_init(); diff -r 89c61e66f45f -r 35248be669e7 tools/blktap2/vhd/lib/libvhd-journal.c --- a/tools/blktap2/vhd/lib/libvhd-journal.c Mon May 14 16:51:27 2012 +0100 +++ b/tools/blktap2/vhd/lib/libvhd-journal.c Mon May 14 16:59:12 2012 +0100 @@ -332,7 +332,7 @@ vhd_journal_write_entry(vhd_journal_t *j err = vhd_journal_write(j, &e, sizeof(vhd_journal_entry_t)); if (err) - err; + return err; return 0; } _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxx http://lists.xensource.com/xen-changelog
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