From c4712e4553f13d87d655325a57538f299402d457 Mon Sep 17 00:00:00 2001 From: "Shawn O. Pearce" Date: Sun, 24 Dec 2006 00:47:23 -0500 Subject: Replace mmap with xmmap, better handling MAP_FAILED. In some cases we did not even bother to check the return value of mmap() and just assume it worked. This is bad, because if we are out of virtual address space the kernel returned MAP_FAILED and we would attempt to dereference that address, segfaulting without any real error output to the user. We are replacing all calls to mmap() with xmmap() and moving all MAP_FAILED checking into that single location. If a mmap call fails we try to release enough least-recently-used pack windows to possibly succeed, then retry the mmap() attempt. If we cannot mmap even after releasing pack memory then we die() as none of our callers have any reasonable recovery strategy for a failed mmap. Signed-off-by: Shawn O. Pearce Signed-off-by: Junio C Hamano --- read-cache.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'read-cache.c') diff --git a/read-cache.c b/read-cache.c index b8d83ccd9f..ca3efbbf0b 100644 --- a/read-cache.c +++ b/read-cache.c @@ -798,7 +798,7 @@ int read_cache_from(const char *path) cache_mmap_size = st.st_size; errno = EINVAL; if (cache_mmap_size >= sizeof(struct cache_header) + 20) - cache_mmap = mmap(NULL, cache_mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); + cache_mmap = xmmap(NULL, cache_mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); } close(fd); if (cache_mmap == MAP_FAILED) -- cgit v1.3 From 5fe5c8300da67a07bd430a33c474ef1498cb1d4b Mon Sep 17 00:00:00 2001 From: "Shawn O. Pearce" Date: Mon, 25 Dec 2006 23:40:58 -0500 Subject: Cleanup read_cache_from error handling. When I converted the mmap() call to xmmap() I failed to cleanup the way this routine handles errors and left some crufty code behind. This is a small cleanup, suggested by Johannes. Signed-off-by: Shawn O. Pearce Signed-off-by: Junio C Hamano --- read-cache.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'read-cache.c') diff --git a/read-cache.c b/read-cache.c index ca3efbbf0b..29cf9abe64 100644 --- a/read-cache.c +++ b/read-cache.c @@ -793,16 +793,16 @@ int read_cache_from(const char *path) die("index file open failed (%s)", strerror(errno)); } - cache_mmap = MAP_FAILED; if (!fstat(fd, &st)) { cache_mmap_size = st.st_size; errno = EINVAL; if (cache_mmap_size >= sizeof(struct cache_header) + 20) cache_mmap = xmmap(NULL, cache_mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); - } + else + die("index file smaller than expected"); + } else + die("cannot stat the open index (%s)", strerror(errno)); close(fd); - if (cache_mmap == MAP_FAILED) - die("index file mmap failed (%s)", strerror(errno)); hdr = cache_mmap; if (verify_hdr(hdr, cache_mmap_size) < 0) -- cgit v1.3