From 632b5e3ee274a2012a88bc32af2d9cf04c5bd363 Mon Sep 17 00:00:00 2001 From: Patrick Steinhardt Date: Tue, 15 Apr 2025 11:38:17 +0200 Subject: object-file: move `xmmap()` into "wrapper.c" The `xmmap()` function is provided by "object-file.c" even though its functionality has nothing to do with the object file subsystem. Move it into "wrapper.c", whose header already declares those functions. Signed-off-by: Patrick Steinhardt Signed-off-by: Junio C Hamano --- wrapper.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) (limited to 'wrapper.c') diff --git a/wrapper.c b/wrapper.c index 8b98593149..3c79778055 100644 --- a/wrapper.c +++ b/wrapper.c @@ -829,3 +829,51 @@ uint32_t git_rand(unsigned flags) return result; } + +static void mmap_limit_check(size_t length) +{ + static size_t limit = 0; + if (!limit) { + limit = git_env_ulong("GIT_MMAP_LIMIT", 0); + if (!limit) + limit = SIZE_MAX; + } + if (length > limit) + die(_("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX), + (uintmax_t)length, (uintmax_t)limit); +} + +void *xmmap_gently(void *start, size_t length, + int prot, int flags, int fd, off_t offset) +{ + void *ret; + + mmap_limit_check(length); + ret = mmap(start, length, prot, flags, fd, offset); + if (ret == MAP_FAILED && !length) + ret = NULL; + return ret; +} + +const char *mmap_os_err(void) +{ + static const char blank[] = ""; +#if defined(__linux__) + if (errno == ENOMEM) { + /* this continues an existing error message: */ + static const char enomem[] = +", check sys.vm.max_map_count and/or RLIMIT_DATA"; + return enomem; + } +#endif /* OS-specific bits */ + return blank; +} + +void *xmmap(void *start, size_t length, + int prot, int flags, int fd, off_t offset) +{ + void *ret = xmmap_gently(start, length, prot, flags, fd, offset); + if (ret == MAP_FAILED) + die_errno(_("mmap failed%s"), mmap_os_err()); + return ret; +} -- cgit v1.3