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authorH.J. Lu <hjl.tools@gmail.com>2018-07-24 12:23:03 -0700
committerH.J. Lu <hjl.tools@gmail.com>2018-07-24 12:23:17 -0700
commit394df3815e8ceec750fd06583eee4896174ce808 (patch)
treebde971c0a45bba24c9ca12514bcae01a5a3f5379 /sysdeps/unix
parent465455306fa5dec3fecd07ddf106a30d95e81465 (diff)
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x86/CET: Extend arch_prctl syscall for CET control
CET arch_prctl bits should be defined in <asm/prctl.h> from Linux kernel header files. Add x86 <include/asm/prctl.h> for pre-CET kernel header files. Note: sysdeps/unix/sysv/linux/x86/include/asm/prctl.h should be removed if <asm/prctl.h> from the required kernel header files contains CET arch_prctl bits. /* CET features: IBT: GNU_PROPERTY_X86_FEATURE_1_IBT SHSTK: GNU_PROPERTY_X86_FEATURE_1_SHSTK */ /* Return CET features in unsigned long long *addr: features: addr[0]. shadow stack base address: addr[1]. shadow stack size: addr[2]. */ # define ARCH_CET_STATUS 0x3001 /* Disable CET features in unsigned int features. */ # define ARCH_CET_DISABLE 0x3002 /* Lock all CET features. */ # define ARCH_CET_LOCK 0x3003 /* Allocate a new shadow stack with unsigned long long *addr: IN: requested shadow stack size: *addr. OUT: allocated shadow stack address: *addr. */ # define ARCH_CET_ALLOC_SHSTK 0x3004 /* Return legacy region bitmap info in unsigned long long *addr: address: addr[0]. size: addr[1]. */ # define ARCH_CET_LEGACY_BITMAP 0x3005 Reviewed-by: Carlos O'Donell <carlos@redhat.com> * sysdeps/unix/sysv/linux/x86/include/asm/prctl.h: New file. * sysdeps/unix/sysv/linux/x86/cpu-features.c: Include <sys/prctl.h> and <asm/prctl.h>. (get_cet_status): Call arch_prctl with ARCH_CET_STATUS. * sysdeps/unix/sysv/linux/x86/dl-cet.h: Include <sys/prctl.h> and <asm/prctl.h>. (dl_cet_allocate_legacy_bitmap): Call arch_prctl with ARCH_CET_LEGACY_BITMAP. (dl_cet_disable_cet): Call arch_prctl with ARCH_CET_DISABLE. (dl_cet_lock_cet): Call arch_prctl with ARCH_CET_LOCK. * sysdeps/x86/libc-start.c: Include <startup.h>.
Diffstat (limited to 'sysdeps/unix')
-rw-r--r--sysdeps/unix/sysv/linux/x86/cpu-features.c8
-rw-r--r--sysdeps/unix/sysv/linux/x86/dl-cet.h30
-rw-r--r--sysdeps/unix/sysv/linux/x86/include/asm/prctl.h32
3 files changed, 64 insertions, 6 deletions
diff --git a/sysdeps/unix/sysv/linux/x86/cpu-features.c b/sysdeps/unix/sysv/linux/x86/cpu-features.c
index 7c9df9b794..8566a265b8 100644
--- a/sysdeps/unix/sysv/linux/x86/cpu-features.c
+++ b/sysdeps/unix/sysv/linux/x86/cpu-features.c
@@ -17,9 +17,17 @@
<http://www.gnu.org/licenses/>. */
#if CET_ENABLED
+# include <sys/prctl.h>
+# include <asm/prctl.h>
+
static inline int __attribute__ ((always_inline))
get_cet_status (void)
{
+ unsigned long long cet_status[3];
+ INTERNAL_SYSCALL_DECL (err);
+ if (INTERNAL_SYSCALL (arch_prctl, err, 2, ARCH_CET_STATUS,
+ cet_status) == 0)
+ return cet_status[0];
return 0;
}
diff --git a/sysdeps/unix/sysv/linux/x86/dl-cet.h b/sysdeps/unix/sysv/linux/x86/dl-cet.h
index ae81e2f2ca..3fbcfebed5 100644
--- a/sysdeps/unix/sysv/linux/x86/dl-cet.h
+++ b/sysdeps/unix/sysv/linux/x86/dl-cet.h
@@ -15,23 +15,41 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
+#include <sys/prctl.h>
+#include <asm/prctl.h>
+
static inline int __attribute__ ((always_inline))
dl_cet_allocate_legacy_bitmap (unsigned long *legacy_bitmap)
{
- /* FIXME: Need syscall support. */
- return -1;
+ /* Allocate legacy bitmap. */
+ INTERNAL_SYSCALL_DECL (err);
+#ifdef __LP64__
+ return (int) INTERNAL_SYSCALL (arch_prctl, err, 2,
+ ARCH_CET_LEGACY_BITMAP, legacy_bitmap);
+#else
+ unsigned long long legacy_bitmap_u64[2];
+ int res = INTERNAL_SYSCALL (arch_prctl, err, 2,
+ ARCH_CET_LEGACY_BITMAP, legacy_bitmap_u64);
+ if (res == 0)
+ {
+ legacy_bitmap[0] = legacy_bitmap_u64[0];
+ legacy_bitmap[1] = legacy_bitmap_u64[1];
+ }
+ return res;
+#endif
}
static inline int __attribute__ ((always_inline))
dl_cet_disable_cet (unsigned int cet_feature)
{
- /* FIXME: Need syscall support. */
- return -1;
+ INTERNAL_SYSCALL_DECL (err);
+ return (int) INTERNAL_SYSCALL (arch_prctl, err, 2, ARCH_CET_DISABLE,
+ cet_feature);
}
static inline int __attribute__ ((always_inline))
dl_cet_lock_cet (void)
{
- /* FIXME: Need syscall support. */
- return -1;
+ INTERNAL_SYSCALL_DECL (err);
+ return (int) INTERNAL_SYSCALL (arch_prctl, err, 2, ARCH_CET_LOCK, 0);
}
diff --git a/sysdeps/unix/sysv/linux/x86/include/asm/prctl.h b/sysdeps/unix/sysv/linux/x86/include/asm/prctl.h
new file mode 100644
index 0000000000..f67f3299b9
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86/include/asm/prctl.h
@@ -0,0 +1,32 @@
+/* FIXME: CET arch_prctl bits should come from the kernel header files.
+ This file should be removed if <asm/prctl.h> from the required kernel
+ header files contains CET arch_prctl bits. */
+
+#include_next <asm/prctl.h>
+
+#ifndef ARCH_CET_STATUS
+/* CET features:
+ IBT: GNU_PROPERTY_X86_FEATURE_1_IBT
+ SHSTK: GNU_PROPERTY_X86_FEATURE_1_SHSTK
+ */
+/* Return CET features in unsigned long long *addr:
+ features: addr[0].
+ shadow stack base address: addr[1].
+ shadow stack size: addr[2].
+ */
+# define ARCH_CET_STATUS 0x3001
+/* Disable CET features in unsigned int features. */
+# define ARCH_CET_DISABLE 0x3002
+/* Lock all CET features. */
+# define ARCH_CET_LOCK 0x3003
+/* Allocate a new shadow stack with unsigned long long *addr:
+ IN: requested shadow stack size: *addr.
+ OUT: allocated shadow stack address: *addr.
+ */
+# define ARCH_CET_ALLOC_SHSTK 0x3004
+/* Return legacy region bitmap info in unsigned long long *addr:
+ address: addr[0].
+ size: addr[1].
+ */
+# define ARCH_CET_LEGACY_BITMAP 0x3005
+#endif /* ARCH_CET_STATUS */