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mirror_zfs/config/kernel-fallocate.m4

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Support the fallocate() file operation. Currently only the (FALLOC_FL_PUNCH_HOLE) flag combination is supported, since it's the only one that matches the behavior of zfs_space(). This makes it pretty much useless in its current form, but it's a start. To support other flag combinations we would need to modify zfs_space() to make it more flexible, or emulate the desired functionality in zpl_fallocate(). Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #334
2011-09-02 11:42:07 +04:00
dnl #
dnl # Linux 2.6.38 - 3.x API
dnl #
AC_DEFUN([ZFS_AC_KERNEL_FILE_FALLOCATE], [
AC_MSG_CHECKING([whether fops->fallocate() exists])
ZFS_LINUX_TRY_COMPILE([
#include <linux/fs.h>
Eliminate runtime function pointer mods in autotools checks PaX/GrSecurity patched kernels implement a dialect of C that relies on a GCC plugin for enforcement. A basic idea in this dialect is that function pointers in structures should not change during runtime. This causes code that modifies function pointers at runtime to fail to compile in many instances. The autotools checks rely on whether or not small test cases compile against a given kernel. Some autotools checks assume some default case if other cases fail. When one of these autotools checks tests a PaX/GrSecurity patched kernel by modifying a function pointer at runtime, the default case will be used. Early detection of such situations is possible by relying on compiler warnings, which are compiler errors when --enable-debug is used. Unfortunately, very few people build ZFS with --enable-debug. The more common situation is that these issues manifest themselves as runtime failures in the form of NULL pointer exceptions. Previous patches that addressed such issues with PaX/GrSecurity compatibility largely relied on rewriting autotools checks to avoid runtime function pointer modification or the addition of PaX/GrSecurity specific checks. This patch takes the previous work to its logical conclusion by eliminating the use of runtime function pointer modification. This permits the removal of PaX-specific autotools checks in favor of ones that work across all supported kernels. This should resolve issues that were reported to occur with PaX/GrSecurity-patched Linux 3.7.5 kernels on Gentoo Linux. https://bugs.gentoo.org/show_bug.cgi?id=457176 We should be able to prevent future regressions in PaX/GrSecurity compatibility by ensuring that all changes to ZFSOnLinux avoid runtime function pointer modification. At the same time, this does not solve the issue of silent failures triggering default cases in the autotools check, which is what permitted these regressions to become runtime failures in the first place. This will need to be addressed in a future patch. Reported-by: Marcin Mirosław <bug@mejor.pl> Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #1300
2013-02-15 03:54:04 +04:00
long test_fallocate(struct file *file, int mode,
loff_t offset, loff_t len) { return 0; }
static const struct file_operations
fops __attribute__ ((unused)) = {
.fallocate = test_fallocate,
Support the fallocate() file operation. Currently only the (FALLOC_FL_PUNCH_HOLE) flag combination is supported, since it's the only one that matches the behavior of zfs_space(). This makes it pretty much useless in its current form, but it's a start. To support other flag combinations we would need to modify zfs_space() to make it more flexible, or emulate the desired functionality in zpl_fallocate(). Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #334
2011-09-02 11:42:07 +04:00
};
Eliminate runtime function pointer mods in autotools checks PaX/GrSecurity patched kernels implement a dialect of C that relies on a GCC plugin for enforcement. A basic idea in this dialect is that function pointers in structures should not change during runtime. This causes code that modifies function pointers at runtime to fail to compile in many instances. The autotools checks rely on whether or not small test cases compile against a given kernel. Some autotools checks assume some default case if other cases fail. When one of these autotools checks tests a PaX/GrSecurity patched kernel by modifying a function pointer at runtime, the default case will be used. Early detection of such situations is possible by relying on compiler warnings, which are compiler errors when --enable-debug is used. Unfortunately, very few people build ZFS with --enable-debug. The more common situation is that these issues manifest themselves as runtime failures in the form of NULL pointer exceptions. Previous patches that addressed such issues with PaX/GrSecurity compatibility largely relied on rewriting autotools checks to avoid runtime function pointer modification or the addition of PaX/GrSecurity specific checks. This patch takes the previous work to its logical conclusion by eliminating the use of runtime function pointer modification. This permits the removal of PaX-specific autotools checks in favor of ones that work across all supported kernels. This should resolve issues that were reported to occur with PaX/GrSecurity-patched Linux 3.7.5 kernels on Gentoo Linux. https://bugs.gentoo.org/show_bug.cgi?id=457176 We should be able to prevent future regressions in PaX/GrSecurity compatibility by ensuring that all changes to ZFSOnLinux avoid runtime function pointer modification. At the same time, this does not solve the issue of silent failures triggering default cases in the autotools check, which is what permitted these regressions to become runtime failures in the first place. This will need to be addressed in a future patch. Reported-by: Marcin Mirosław <bug@mejor.pl> Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #1300
2013-02-15 03:54:04 +04:00
],[
Support the fallocate() file operation. Currently only the (FALLOC_FL_PUNCH_HOLE) flag combination is supported, since it's the only one that matches the behavior of zfs_space(). This makes it pretty much useless in its current form, but it's a start. To support other flag combinations we would need to modify zfs_space() to make it more flexible, or emulate the desired functionality in zpl_fallocate(). Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #334
2011-09-02 11:42:07 +04:00
],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_FILE_FALLOCATE, 1, [fops->fallocate() exists])
],[
AC_MSG_RESULT(no)
])
])
dnl #
dnl # Linux 2.6.x - 2.6.37 API
dnl #
AC_DEFUN([ZFS_AC_KERNEL_INODE_FALLOCATE], [
AC_MSG_CHECKING([whether iops->fallocate() exists])
ZFS_LINUX_TRY_COMPILE([
#include <linux/fs.h>
Eliminate runtime function pointer mods in autotools checks PaX/GrSecurity patched kernels implement a dialect of C that relies on a GCC plugin for enforcement. A basic idea in this dialect is that function pointers in structures should not change during runtime. This causes code that modifies function pointers at runtime to fail to compile in many instances. The autotools checks rely on whether or not small test cases compile against a given kernel. Some autotools checks assume some default case if other cases fail. When one of these autotools checks tests a PaX/GrSecurity patched kernel by modifying a function pointer at runtime, the default case will be used. Early detection of such situations is possible by relying on compiler warnings, which are compiler errors when --enable-debug is used. Unfortunately, very few people build ZFS with --enable-debug. The more common situation is that these issues manifest themselves as runtime failures in the form of NULL pointer exceptions. Previous patches that addressed such issues with PaX/GrSecurity compatibility largely relied on rewriting autotools checks to avoid runtime function pointer modification or the addition of PaX/GrSecurity specific checks. This patch takes the previous work to its logical conclusion by eliminating the use of runtime function pointer modification. This permits the removal of PaX-specific autotools checks in favor of ones that work across all supported kernels. This should resolve issues that were reported to occur with PaX/GrSecurity-patched Linux 3.7.5 kernels on Gentoo Linux. https://bugs.gentoo.org/show_bug.cgi?id=457176 We should be able to prevent future regressions in PaX/GrSecurity compatibility by ensuring that all changes to ZFSOnLinux avoid runtime function pointer modification. At the same time, this does not solve the issue of silent failures triggering default cases in the autotools check, which is what permitted these regressions to become runtime failures in the first place. This will need to be addressed in a future patch. Reported-by: Marcin Mirosław <bug@mejor.pl> Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #1300
2013-02-15 03:54:04 +04:00
long test_fallocate(struct inode *inode, int mode,
loff_t offset, loff_t len) { return 0; }
static const struct inode_operations
fops __attribute__ ((unused)) = {
.fallocate = test_fallocate,
Fix build failures on PaX/GRSecurity patched kernels Gentoo Hardened kernels include the PaX/GRSecurity patches. They use a dialect of C that relies on a GCC plugin. In particular, struct file_operations has been marked do_const in the PaX/GRSecurity dialect, which causes GCC to consider all instances of it as const. This caused failures in the autotools checks and the ZFS source code. To address this, we modify the autotools checks to take into account differences between the PaX C dialect and the regular C dialect. We also modify struct zfs_acl's z_ops member to be a pointer to a function pointer table. Lastly, we modify zpl_put_link() to address a PaX change to the function prototype of nd_get_link(). This avoids compiler errors in the PaX/GRSecurity dialect. Note that the change in zpl_put_link() causes a warning that becomes a build failure when debugging is enabled. Fixing that warning requires ryao/spl@5ca50ef459c59bc74b7a7cd3af7311da2b1cd2c3. Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #484
2012-05-31 07:25:31 +04:00
};
Eliminate runtime function pointer mods in autotools checks PaX/GrSecurity patched kernels implement a dialect of C that relies on a GCC plugin for enforcement. A basic idea in this dialect is that function pointers in structures should not change during runtime. This causes code that modifies function pointers at runtime to fail to compile in many instances. The autotools checks rely on whether or not small test cases compile against a given kernel. Some autotools checks assume some default case if other cases fail. When one of these autotools checks tests a PaX/GrSecurity patched kernel by modifying a function pointer at runtime, the default case will be used. Early detection of such situations is possible by relying on compiler warnings, which are compiler errors when --enable-debug is used. Unfortunately, very few people build ZFS with --enable-debug. The more common situation is that these issues manifest themselves as runtime failures in the form of NULL pointer exceptions. Previous patches that addressed such issues with PaX/GrSecurity compatibility largely relied on rewriting autotools checks to avoid runtime function pointer modification or the addition of PaX/GrSecurity specific checks. This patch takes the previous work to its logical conclusion by eliminating the use of runtime function pointer modification. This permits the removal of PaX-specific autotools checks in favor of ones that work across all supported kernels. This should resolve issues that were reported to occur with PaX/GrSecurity-patched Linux 3.7.5 kernels on Gentoo Linux. https://bugs.gentoo.org/show_bug.cgi?id=457176 We should be able to prevent future regressions in PaX/GrSecurity compatibility by ensuring that all changes to ZFSOnLinux avoid runtime function pointer modification. At the same time, this does not solve the issue of silent failures triggering default cases in the autotools check, which is what permitted these regressions to become runtime failures in the first place. This will need to be addressed in a future patch. Reported-by: Marcin Mirosław <bug@mejor.pl> Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #1300
2013-02-15 03:54:04 +04:00
],[
Fix build failures on PaX/GRSecurity patched kernels Gentoo Hardened kernels include the PaX/GRSecurity patches. They use a dialect of C that relies on a GCC plugin. In particular, struct file_operations has been marked do_const in the PaX/GRSecurity dialect, which causes GCC to consider all instances of it as const. This caused failures in the autotools checks and the ZFS source code. To address this, we modify the autotools checks to take into account differences between the PaX C dialect and the regular C dialect. We also modify struct zfs_acl's z_ops member to be a pointer to a function pointer table. Lastly, we modify zpl_put_link() to address a PaX change to the function prototype of nd_get_link(). This avoids compiler errors in the PaX/GRSecurity dialect. Note that the change in zpl_put_link() causes a warning that becomes a build failure when debugging is enabled. Fixing that warning requires ryao/spl@5ca50ef459c59bc74b7a7cd3af7311da2b1cd2c3. Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #484
2012-05-31 07:25:31 +04:00
],[
AC_MSG_RESULT(yes)
Eliminate runtime function pointer mods in autotools checks PaX/GrSecurity patched kernels implement a dialect of C that relies on a GCC plugin for enforcement. A basic idea in this dialect is that function pointers in structures should not change during runtime. This causes code that modifies function pointers at runtime to fail to compile in many instances. The autotools checks rely on whether or not small test cases compile against a given kernel. Some autotools checks assume some default case if other cases fail. When one of these autotools checks tests a PaX/GrSecurity patched kernel by modifying a function pointer at runtime, the default case will be used. Early detection of such situations is possible by relying on compiler warnings, which are compiler errors when --enable-debug is used. Unfortunately, very few people build ZFS with --enable-debug. The more common situation is that these issues manifest themselves as runtime failures in the form of NULL pointer exceptions. Previous patches that addressed such issues with PaX/GrSecurity compatibility largely relied on rewriting autotools checks to avoid runtime function pointer modification or the addition of PaX/GrSecurity specific checks. This patch takes the previous work to its logical conclusion by eliminating the use of runtime function pointer modification. This permits the removal of PaX-specific autotools checks in favor of ones that work across all supported kernels. This should resolve issues that were reported to occur with PaX/GrSecurity-patched Linux 3.7.5 kernels on Gentoo Linux. https://bugs.gentoo.org/show_bug.cgi?id=457176 We should be able to prevent future regressions in PaX/GrSecurity compatibility by ensuring that all changes to ZFSOnLinux avoid runtime function pointer modification. At the same time, this does not solve the issue of silent failures triggering default cases in the autotools check, which is what permitted these regressions to become runtime failures in the first place. This will need to be addressed in a future patch. Reported-by: Marcin Mirosław <bug@mejor.pl> Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #1300
2013-02-15 03:54:04 +04:00
AC_DEFINE(HAVE_INODE_FALLOCATE, 1, [fops->fallocate() exists])
Fix build failures on PaX/GRSecurity patched kernels Gentoo Hardened kernels include the PaX/GRSecurity patches. They use a dialect of C that relies on a GCC plugin. In particular, struct file_operations has been marked do_const in the PaX/GRSecurity dialect, which causes GCC to consider all instances of it as const. This caused failures in the autotools checks and the ZFS source code. To address this, we modify the autotools checks to take into account differences between the PaX C dialect and the regular C dialect. We also modify struct zfs_acl's z_ops member to be a pointer to a function pointer table. Lastly, we modify zpl_put_link() to address a PaX change to the function prototype of nd_get_link(). This avoids compiler errors in the PaX/GRSecurity dialect. Note that the change in zpl_put_link() causes a warning that becomes a build failure when debugging is enabled. Fixing that warning requires ryao/spl@5ca50ef459c59bc74b7a7cd3af7311da2b1cd2c3. Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #484
2012-05-31 07:25:31 +04:00
],[
AC_MSG_RESULT(no)
])
])
Support the fallocate() file operation. Currently only the (FALLOC_FL_PUNCH_HOLE) flag combination is supported, since it's the only one that matches the behavior of zfs_space(). This makes it pretty much useless in its current form, but it's a start. To support other flag combinations we would need to modify zfs_space() to make it more flexible, or emulate the desired functionality in zpl_fallocate(). Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Issue #334
2011-09-02 11:42:07 +04:00
dnl #
dnl # The fallocate callback was moved from the inode_operations
dnl # structure to the file_operations structure.
dnl #
AC_DEFUN([ZFS_AC_KERNEL_FALLOCATE], [
ZFS_AC_KERNEL_FILE_FALLOCATE
ZFS_AC_KERNEL_INODE_FALLOCATE
])
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