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authorAnshuman Khandual <khandual@linux.vnet.ibm.com>2016-07-28 10:57:31 +0800
committerMichael Ellerman <mpe@ellerman.id.au>2016-08-01 11:15:15 +1000
commit8d460f6156cd55d981d109f01b82cbea8cf80e57 (patch)
treeac6fb3e870b01f08c31559ee0ee77bfc4cde65dc /arch/powerpc
parent0dc696bcf2e86f48a23fb95ca2f40c8708241e7e (diff)
powerpc/process: Add the function flush_tmregs_to_thread
This patch creates a function flush_tmregs_to_thread which will then be used by subsequent patches in this series. The function checks for self tracing ptrace interface attempts while in the TM context and logs appropriate warning message. Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/include/asm/switch_to.h8
-rw-r--r--arch/powerpc/kernel/process.c20
2 files changed, 28 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/switch_to.h b/arch/powerpc/include/asm/switch_to.h
index 17c8380673a6..0a74ebe934e1 100644
--- a/arch/powerpc/include/asm/switch_to.h
+++ b/arch/powerpc/include/asm/switch_to.h
@@ -75,6 +75,14 @@ static inline void disable_kernel_spe(void)
static inline void __giveup_spe(struct task_struct *t) { }
#endif
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+extern void flush_tmregs_to_thread(struct task_struct *);
+#else
+static inline void flush_tmregs_to_thread(struct task_struct *t)
+{
+}
+#endif
+
static inline void clear_task_ebb(struct task_struct *t)
{
#ifdef CONFIG_PPC_BOOK3S_64
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 9ee2623e0f67..58ccf86415b4 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1074,6 +1074,26 @@ static inline void restore_sprs(struct thread_struct *old_thread,
#endif
}
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+void flush_tmregs_to_thread(struct task_struct *tsk)
+{
+ /*
+ * Process self tracing is not yet supported through
+ * ptrace interface. Ptrace generic code should have
+ * prevented this from happening in the first place.
+ * Warn once here with the message, if some how it
+ * is attempted.
+ */
+ WARN_ONCE(tsk == current,
+ "Not expecting ptrace on self: TM regs may be incorrect\n");
+
+ /*
+ * If task is not current, it should have been flushed
+ * already to it's thread_struct during __switch_to().
+ */
+}
+#endif
+
struct task_struct *__switch_to(struct task_struct *prev,
struct task_struct *new)
{