[PATCH 12/24] arm64: ilp32: add is_ilp32_compat_{task,thread} and TIF_32BIT_AARCH64

[Yury Norov]

ILP32 tasks are needed to be distinguished from LP64 and AARCH32.
This patch adds helper functions is_ilp32_compat_{task,thread} and
thread flag TIF_32BIT_AARCH64 to address it. This is a preparation
for following patches in ILP32 patchset.

For consistency, SET_PERSONALITY is changed here accordingly.

Signed-off-by: Andrew Pinski <Andrew.Pinski@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Philipp Tomsich <philipp.tomsich@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Christoph Muellner <christoph.muellner@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx>
Reviewed-by: David Daney <ddaney@xxxxxxxxxxxxxxxxxx>
---
 arch/arm64/include/asm/elf.h         |  2 ++
 arch/arm64/include/asm/is_compat.h   | 30 ++++++++++++++++++++++++++--
 arch/arm64/include/asm/thread_info.h |  2 ++
 3 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h
index b4b10eefc667..023b2fbc1454 100644
--- a/arch/arm64/include/asm/elf.h
+++ b/arch/arm64/include/asm/elf.h
@@ -143,6 +143,7 @@ typedef struct user_fpsimd_state elf_fpregset_t;
 
 #define SET_PERSONALITY(ex)						\
 ({									\
+	clear_thread_flag(TIF_32BIT_AARCH64);				\
 	clear_thread_flag(TIF_32BIT);					\
 	current->personality &= ~READ_IMPLIES_EXEC;			\
 })
@@ -194,6 +195,7 @@ typedef compat_elf_greg_t		compat_elf_gregset_t[COMPAT_ELF_NGREG];
  */
 #define COMPAT_SET_PERSONALITY(ex)					\
 ({									\
+	clear_thread_flag(TIF_32BIT_AARCH64);				\
 	set_thread_flag(TIF_32BIT);					\
  })
 #define COMPAT_ARCH_DLINFO
diff --git a/arch/arm64/include/asm/is_compat.h b/arch/arm64/include/asm/is_compat.h
index 19868588fbef..484c01def030 100644
--- a/arch/arm64/include/asm/is_compat.h
+++ b/arch/arm64/include/asm/is_compat.h
@@ -33,18 +33,44 @@ static inline int is_a32_compat_thread(struct thread_info *thread)
 
 #endif /* CONFIG_AARCH32_EL0 */
 
+#ifdef CONFIG_ARM64_ILP32
+
+static inline int is_ilp32_compat_task(void)
+{
+	return test_thread_flag(TIF_32BIT_AARCH64);
+}
+
+static inline int is_ilp32_compat_thread(struct thread_info *thread)
+{
+	return test_ti_thread_flag(thread, TIF_32BIT_AARCH64);
+}
+
+#else
+
+static inline int is_ilp32_compat_task(void)
+{
+	return 0;
+}
+
+static inline int is_ilp32_compat_thread(struct thread_info *thread)
+{
+	return 0;
+}
+
+#endif /* CONFIG_ARM64_ILP32 */
+
 #ifdef CONFIG_COMPAT
 
 static inline int is_compat_task(void)
 {
-	return is_a32_compat_task();
+	return is_a32_compat_task() || is_ilp32_compat_task();
 }
 
 #endif /* CONFIG_COMPAT */
 
 static inline int is_compat_thread(struct thread_info *thread)
 {
-	return is_a32_compat_thread(thread);
+	return is_a32_compat_thread(thread) || is_ilp32_compat_thread(thread);
 }
 
 
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 6d2d58daa9d7..8ed56630e6a5 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -94,6 +94,7 @@ void arch_release_task_struct(struct task_struct *tsk);
 #define TIF_32BIT		22	/* AARCH32 process */
 #define TIF_SVE			23	/* Scalable Vector Extension in use */
 #define TIF_SVE_VL_INHERIT	24	/* Inherit sve_vl_onexec across exec */
+#define TIF_32BIT_AARCH64	25	/* 32 bit process on AArch64(ILP32) */
 
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
@@ -108,6 +109,7 @@ void arch_release_task_struct(struct task_struct *tsk);
 #define _TIF_FSCHECK		(1 << TIF_FSCHECK)
 #define _TIF_32BIT		(1 << TIF_32BIT)
 #define _TIF_SVE		(1 << TIF_SVE)
+#define _TIF_32BIT_AARCH64	(1 << TIF_32BIT_AARCH64)
 
 #define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
 				 _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \
-- 
2.17.0