Re: write() _will_ fail on Mac OS X/XNU if nbytes > INT_MAX
From: Filipe Cabecinhas <hidden>
Date: 2016-06-15 22:57:12
Subsystem:
kernel build + files below scripts/ (unless maintained elsewhere), the rest · Maintainers:
Nathan Chancellor, Nicolas Schier, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2016-06-15 · Re: write() _will_ fail on Mac OS X/XNU if nbytes > INT_MAX · Erik Faye-Lund <hidden>
- 2016-06-15 · Re: write() _will_ fail on Mac OS X/XNU if nbytes > INT_MAX · Torsten Bögershausen <hidden>
- 2016-06-15 · Re: write() _will_ fail on Mac OS X/XNU if nbytes > INT_MAX · Junio C Hamano <hidden>
- 2016-06-15 · Re: write() _will_ fail on Mac OS X/XNU if nbytes > INT_MAX · Junio C Hamano <hidden>
- 2016-06-15 · Re: write() _will_ fail on Mac OS X/XNU if nbytes > INT_MAX · Filipe Cabecinhas <hidden>
Due to a bug in the Darwin kernel, write() calls have a maximum size of INT_MAX bytes. This patch introduces a new compat function: clipped_write This function behaves the same as write() but will write, at most, INT_MAX characters. It may be necessary to include this function on Windows, too. Signed-off-by: Filipe Cabecinhas <redacted> --- Makefile | 5 +++++ compat/clipped-write.c | 13 +++++++++++++ config.mak.uname | 1 + git-compat-util.h | 5 +++++ 4 files changed, 24 insertions(+) create mode 100644 compat/clipped-write.c
diff --git a/Makefile b/Makefile
index 0f931a2..ccb8f3f 100644
--- a/Makefile
+++ b/Makefile@@ -1466,6 +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 (,$(XDL_FAST_HASH)) BASIC_CFLAGS += -DXDL_FAST_HASH endif
diff --git a/compat/clipped-write.c b/compat/clipped-write.c
new file mode 100644
index 0000000..9183698
--- /dev/null
+++ b/compat/clipped-write.c@@ -0,0 +1,13 @@ +#include <limits.h> +#include <unistd.h> + +/* + * Version of write that will write at most INT_MAX bytes. + * Workaround a xnu bug on Mac OS X + */ +ssize_t clipped_write(int fildes, const void *buf, size_t nbyte) +{ + if (nbyte > INT_MAX) + nbyte = INT_MAX; + return write(fildes, buf, nbyte); +}
diff --git a/config.mak.uname b/config.mak.uname
index d78fd3d..174703b 100644
--- a/config.mak.uname
+++ b/config.mak.uname@@ -95,6 +95,7 @@ ifeq ($(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 e955bb5..a96db23 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h@@ -185,6 +185,11 @@ int get_st_mode_bits(const char *path, int *mode); #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); --
1.8.2.1.343.g13c32df