Add --disable-syscall.

This resolves #517.
This commit is contained in:
Jason Evans 2016-12-03 16:47:36 -08:00
parent 7179351a45
commit acb7b1f53e
5 changed files with 33 additions and 15 deletions

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@ -203,6 +203,11 @@ any of the following arguments (not a definitive list) to 'configure':
most extreme case increases physical memory usage for the 16 KiB size class
to 20 KiB.
--disable-syscall
Disable use of syscall(2) rather than {open,read,write,close}(2). This is
intended as a workaround for systems that place security limitations on
syscall(2).
--with-xslroot=<path>
Specify where to find DocBook XSL stylesheets when building the
documentation.

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@ -1366,20 +1366,33 @@ if test "x${je_cv_mach_absolute_time}" = "xyes" ; then
AC_DEFINE([JEMALLOC_HAVE_MACH_ABSOLUTE_TIME])
fi
dnl Check if syscall(2) is usable. Treat warnings as errors, so that e.g. OS X
dnl 10.12's deprecation warning prevents use.
SAVED_CFLAGS="${CFLAGS}"
JE_CFLAGS_APPEND([-Werror])
JE_COMPILABLE([syscall(2)], [
dnl Use syscall(2) (if available) by default.
AC_ARG_ENABLE([syscall],
[AS_HELP_STRING([--disable-syscall], [Disable use of syscall(2)])],
[if test "x$enable_syscall" = "xno" ; then
enable_syscall="0"
else
enable_syscall="1"
fi
],
[enable_syscall="1"]
)
if test "x$enable_syscall" = "x1" ; then
dnl Check if syscall(2) is usable. Treat warnings as errors, so that e.g. OS
dnl X 10.12's deprecation warning prevents use.
SAVED_CFLAGS="${CFLAGS}"
JE_CFLAGS_APPEND([-Werror])
JE_COMPILABLE([syscall(2)], [
#include <sys/syscall.h>
#include <unistd.h>
], [
syscall(SYS_write, 2, "hello", 5);
],
[je_cv_syscall])
CFLAGS="${SAVED_CFLAGS}"
if test "x$je_cv_syscall" = "xyes" ; then
AC_DEFINE([JEMALLOC_HAVE_SYSCALL], [ ])
[je_cv_syscall])
CFLAGS="${SAVED_CFLAGS}"
if test "x$je_cv_syscall" = "xyes" ; then
AC_DEFINE([JEMALLOC_USE_SYSCALL], [ ])
fi
fi
dnl Check if the GNU-specific secure_getenv function exists.

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@ -66,8 +66,8 @@
*/
#undef JEMALLOC_OSSPIN
/* Defined if syscall(2) is available. */
#undef JEMALLOC_HAVE_SYSCALL
/* Defined if syscall(2) is usable. */
#undef JEMALLOC_USE_SYSCALL
/*
* Defined if secure_getenv(3) is available.

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@ -219,7 +219,7 @@ os_overcommits_proc(void)
char buf[1];
ssize_t nread;
#if defined(JEMALLOC_HAVE_SYSCALL) && defined(SYS_open)
#if defined(JEMALLOC_USE_SYSCALL) && defined(SYS_open)
fd = (int)syscall(SYS_open, "/proc/sys/vm/overcommit_memory", O_RDONLY);
#else
fd = open("/proc/sys/vm/overcommit_memory", O_RDONLY);
@ -227,13 +227,13 @@ os_overcommits_proc(void)
if (fd == -1)
return (false); /* Error. */
#if defined(JEMALLOC_HAVE_SYSCALL) && defined(SYS_read)
#if defined(JEMALLOC_USE_SYSCALL) && defined(SYS_read)
nread = (ssize_t)syscall(SYS_read, fd, &buf, sizeof(buf));
#else
nread = read(fd, &buf, sizeof(buf));
#endif
#if defined(JEMALLOC_HAVE_SYSCALL) && defined(SYS_close)
#if defined(JEMALLOC_USE_SYSCALL) && defined(SYS_close)
syscall(SYS_close, fd);
#else
close(fd);

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@ -49,7 +49,7 @@ static void
wrtmessage(void *cbopaque, const char *s)
{
#if defined(JEMALLOC_HAVE_SYSCALL) && defined(SYS_write)
#if defined(JEMALLOC_USE_SYSCALL) && defined(SYS_write)
/*
* Use syscall(2) rather than write(2) when possible in order to avoid
* the possibility of memory allocation within libc. This is necessary