From 6c642a878688adf46b226903858b53e2d31ac5c3 Mon Sep 17 00:00:00 2001 From: Filipe Cabecinhas Date: Fri, 10 May 2013 15:24:57 -0700 Subject: [PATCH] compate/clipped-write.c: large write(2) fails on Mac OS X/XNU Due to a bug in the Darwin kernel, write(2) calls have a maximum size of INT_MAX bytes. Introduce a new compat function, clipped_write(), that only writes at most INT_MAX bytes and returns the number of bytes written, as a substitute for write(2), and allow platforms that need this to enable it from the build mechanism with NEEDS_CLIPPED_WRITE. Set it for Mac OS X by default. It may be necessary to include this function on Windows, too. Signed-off-by: Filipe Cabecinhas Signed-off-by: Junio C Hamano --- Makefile | 8 ++++++++ compat/clipped-write.c | 13 +++++++++++++ config.mak.uname | 1 + git-compat-util.h | 5 +++++ 4 files changed, 27 insertions(+) create mode 100644 compat/clipped-write.c diff --git a/Makefile b/Makefile index 26d3332755..0434715f0e 100644 --- a/Makefile +++ b/Makefile @@ -69,6 +69,9 @@ all:: # Define NO_MSGFMT_EXTENDED_OPTIONS if your implementation of msgfmt # doesn't support GNU extensions like --check and --statistics # +# Define NEEDS_CLIPPED_WRITE if your write(2) cannot write more than +# INT_MAX bytes at once (e.g. MacOS X). +# # Define HAVE_PATHS_H if you have paths.h and want to use the default PATH # it specifies. # @@ -1463,6 +1466,11 @@ ifndef NO_MSGFMT_EXTENDED_OPTIONS MSGFMT += --check --statistics endif +ifdef NEEDS_CLIPPED_WRITE + BASIC_CFLAGS += -DNEEDS_CLIPPED_WRITE + COMPAT_OBJS += compat/clipped-write.o +endif + ifneq (,$(XDL_FAST_HASH)) BASIC_CFLAGS += -DXDL_FAST_HASH endif diff --git a/compat/clipped-write.c b/compat/clipped-write.c new file mode 100644 index 0000000000..b8f98ff77f --- /dev/null +++ b/compat/clipped-write.c @@ -0,0 +1,13 @@ +#include "../git-compat-util.h" +#undef write + +/* + * Version of write that will write at most INT_MAX bytes. + * Workaround a xnu bug on Mac OS X + */ +ssize_t clipped_write(int fildes, const void *buf, size_t nbyte) +{ + if (nbyte > INT_MAX) + nbyte = INT_MAX; + return write(fildes, buf, nbyte); +} diff --git a/config.mak.uname b/config.mak.uname index e09af8fc13..e689a9a867 100644 --- a/config.mak.uname +++ b/config.mak.uname @@ -95,6 +95,7 @@ ifeq ($(uname_S),Darwin) NO_MEMMEM = YesPlease USE_ST_TIMESPEC = YesPlease HAVE_DEV_TTY = YesPlease + NEEDS_CLIPPED_WRITE = YesPlease COMPAT_OBJS += compat/precompose_utf8.o BASIC_CFLAGS += -DPRECOMPOSE_UNICODE endif diff --git a/git-compat-util.h b/git-compat-util.h index b636e0dd0c..3144b8da1e 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -181,6 +181,11 @@ typedef unsigned long uintptr_t; #define probe_utf8_pathname_composition(a,b) #endif +#ifdef NEEDS_CLIPPED_WRITE +ssize_t clipped_write(int fildes, const void *buf, size_t nbyte); +#define write(x,y,z) clipped_write((x),(y),(z)) +#endif + #ifdef MKDIR_WO_TRAILING_SLASH #define mkdir(a,b) compat_mkdir_wo_trailing_slash((a),(b)) extern int compat_mkdir_wo_trailing_slash(const char*, mode_t);