livepatch/powerpc: add TIF_PATCH_PENDING thread flag

Add the TIF_PATCH_PENDING thread flag to enable the new livepatch
per-task consistency model for powerpc.  The bit getting set indicates
the thread has a pending patch which needs to be applied when the thread
exits the kernel.

The bit is included in the _TIF_USER_WORK_MASK macro so that
do_notify_resume() and klp_update_patch_state() get called when the bit
is set.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Reviewed-by: Balbir Singh <bsingharora@gmail.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 87e4b2d..6fc6464 100644 (file)
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -92,6 +92,7 @@ static inline struct thread_info *current_thread_info(void)
                                           TIF_NEED_RESCHED */
 #define TIF_32BIT              4       /* 32 bit binary */
 #define TIF_RESTORE_TM         5       /* need to restore TM FP/VEC/VSX */
+#define TIF_PATCH_PENDING      6       /* pending live patching update */
 #define TIF_SYSCALL_AUDIT      7       /* syscall auditing active */
 #define TIF_SINGLESTEP         8       /* singlestepping active */
 #define TIF_NOHZ               9       /* in adaptive nohz mode */
@@ -115,6 +116,7 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_POLLING_NRFLAG    (1<<TIF_POLLING_NRFLAG)
 #define _TIF_32BIT             (1<<TIF_32BIT)
 #define _TIF_RESTORE_TM                (1<<TIF_RESTORE_TM)
+#define _TIF_PATCH_PENDING     (1<<TIF_PATCH_PENDING)
 #define _TIF_SYSCALL_AUDIT     (1<<TIF_SYSCALL_AUDIT)
 #define _TIF_SINGLESTEP                (1<<TIF_SINGLESTEP)
 #define _TIF_SECCOMP           (1<<TIF_SECCOMP)
@@ -131,7 +133,7 @@ static inline struct thread_info *current_thread_info(void)
 
 #define _TIF_USER_WORK_MASK    (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
                                 _TIF_NOTIFY_RESUME | _TIF_UPROBE | \
-                                _TIF_RESTORE_TM)
+                                _TIF_RESTORE_TM | _TIF_PATCH_PENDING)
 #define _TIF_PERSYSCALL_MASK   (_TIF_RESTOREALL|_TIF_NOERROR)
 
 /* Bits in local_flags */

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 3a36711..e9436c5 100644 (file)
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -14,6 +14,7 @@
 #include <linux/uprobes.h>
 #include <linux/key.h>
 #include <linux/context_tracking.h>
+#include <linux/livepatch.h>
 #include <asm/hw_breakpoint.h>
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
@@ -162,6 +163,9 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
                tracehook_notify_resume(regs);
        }
 
+       if (thread_info_flags & _TIF_PATCH_PENDING)
+               klp_update_patch_state(current);
+
        user_enter();
 }