powerpc: Syscall hooks for context tracking subsystem

This is the syscall slow path hooks for context tracking subsystem,
corresponding to
[PATCH] x86: Syscall hooks for userspace RCU extended QS
  commit bf5a3c13b939813d28ce26c01425054c740d6731

TIF_MEMDIE is moved to the second 16-bits (with value 17), as it seems there
is no asm code using it. TIF_NOHZ is added to _TIF_SYCALL_T_OR_A, so it is
better for it to be in the same 16 bits with others in the group, so in the
asm code, andi. with this group could work.

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
index 8ceea14d6fe44a20d0d807e28a4ca63477f18863..ba7b1973866e1933486f47ed59e3aa0efe799f34 100644 (file)
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -97,7 +97,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_PERFMON_CTXSW      6       /* perfmon needs ctxsw calls */
 #define TIF_SYSCALL_AUDIT      7       /* syscall auditing active */
 #define TIF_SINGLESTEP         8       /* singlestepping active */
-#define TIF_MEMDIE             9       /* is terminating due to OOM killer */
+#define TIF_NOHZ               9       /* in adaptive nohz mode */
 #define TIF_SECCOMP            10      /* secure computing */
 #define TIF_RESTOREALL         11      /* Restore all regs (implies NOERROR) */
 #define TIF_NOERROR            12      /* Force successful syscall return */
@@ -106,6 +106,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SYSCALL_TRACEPOINT 15      /* syscall tracepoint instrumentation */
 #define TIF_EMULATE_STACK_STORE        16      /* Is an instruction emulation
                                                for stack store? */
+#define TIF_MEMDIE             17      /* is terminating due to OOM killer */
 
 /* as above, but as bit values */
 #define _TIF_SYSCALL_TRACE     (1<<TIF_SYSCALL_TRACE)
@@ -124,8 +125,10 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_UPROBE            (1<<TIF_UPROBE)
 #define _TIF_SYSCALL_TRACEPOINT        (1<<TIF_SYSCALL_TRACEPOINT)
 #define _TIF_EMULATE_STACK_STORE       (1<<TIF_EMULATE_STACK_STORE)
+#define _TIF_NOHZ              (1<<TIF_NOHZ)
 #define _TIF_SYSCALL_T_OR_A    (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
-                                _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT)
+                                _TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \
+                                _TIF_NOHZ)
 
 #define _TIF_USER_WORK_MASK    (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
                                 _TIF_NOTIFY_RESUME | _TIF_UPROBE)

diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 3b14d320e69f81737b447b59bcef4046edde0b5a..98c2fc198712aabe3f90055e24d653df604be78e 100644 (file)
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -32,6 +32,7 @@
 #include <trace/syscall.h>
 #include <linux/hw_breakpoint.h>
 #include <linux/perf_event.h>
+#include <linux/context_tracking.h>
 
 #include <asm/uaccess.h>
 #include <asm/page.h>
@@ -1788,6 +1789,8 @@ long do_syscall_trace_enter(struct pt_regs *regs)
 {
        long ret = 0;
 
+       user_exit();
+
        secure_computing_strict(regs->gpr[0]);
 
        if (test_thread_flag(TIF_SYSCALL_TRACE) &&
@@ -1832,4 +1835,6 @@ void do_syscall_trace_leave(struct pt_regs *regs)
        step = test_thread_flag(TIF_SINGLESTEP);
        if (step || test_thread_flag(TIF_SYSCALL_TRACE))
                tracehook_report_syscall_exit(regs, step);
+
+       user_enter();
 }