arm64: ilp32: add is_ilp32_compat_{task,thread} and TIF_32BIT_AARCH64

maillist inclusion
category: feature
bugzilla: 46790
CVE: NA

Reference: https://github.com/norov/linux/commits/ilp32-5.2

--------------------------------

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: NAndrew Pinski <Andrew.Pinski@caviumnetworks.com>
Signed-off-by: NPhilipp Tomsich <philipp.tomsich@theobroma-systems.com>
Signed-off-by: NChristoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: NYury Norov <ynorov@caviumnetworks.com>
Reviewed-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NYury Norov <ynorov@marvell.com>

 Conflicts:
	arch/arm64/include/asm/thread_info.h
Signed-off-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>

arch/arm64/include/asm/elf.h

@@ -164,6 +164,7 @@ 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;			\
 })
@@ -225,6 +226,7 @@ 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);					\
  })
 #ifdef CONFIG_COMPAT_VDSO

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);
 }
 
 

arch/arm64/include/asm/thread_info.h

@@ -82,6 +82,7 @@ void arch_release_task_struct(struct task_struct *tsk);
 #define TIF_SVE_VL_INHERIT	24	/* Inherit sve_vl_onexec across exec */
 #define TIF_SSBD		25	/* Wants SSB mitigation */
 #define TIF_TAGGED_ADDR		26	/* Allow tagged user addresses */
+#define TIF_32BIT_AARCH64	27	/* 32 bit process on AArch64(ILP32) */
 
 #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
@@ -98,6 +99,7 @@ void arch_release_task_struct(struct task_struct *tsk);
 #define _TIF_32BIT		(1 << TIF_32BIT)
 #define _TIF_SVE		(1 << TIF_SVE)
 #define _TIF_MTE_ASYNC_FAULT	(1 << TIF_MTE_ASYNC_FAULT)
+#define _TIF_32BIT_AARCH64	(1 << TIF_32BIT_AARCH64)
 
 #define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
 				 _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \