arm64: cleanup {COMPAT_,}SET_PERSONALITY() macro

There is some work that should be done after setting the personality.
Currently it's done in the macro, which is not the best idea.

In this patch new arch_setup_new_exec() routine is introduced, and all
setup code is moved there, as suggested by Catalin:
https://lkml.org/lkml/2017/8/4/494

Cc: Pratyush Anand <panand@redhat.com>
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
[catalin.marinas@arm.com: comments changed or removed]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

3 files changed, 11 insertions, 2 deletions

diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h
index f4e33f8356ca..c55043709c69 100644
--- a/arch/arm64/include/asm/elf.h
+++ b/arch/arm64/include/asm/elf.h
@@ -139,7 +139,6 @@ typedef struct user_fpsimd_state elf_fpregset_t;
 
 #define SET_PERSONALITY(ex)                                             \
 ({                                                                      \
-        current->mm->context.flags = 0;                                 \
         clear_thread_flag(TIF_32BIT);                                   \
         current->personality &= ~READ_IMPLIES_EXEC;                     \
 })
@@ -195,7 +194,6 @@ typedef compat_elf_greg_t		compat_elf_gregset_t[COMPAT_ELF_NGREG];
  */
 #define COMPAT_SET_PERSONALITY(ex)                                      \
 ({                                                                      \
-        current->mm->context.flags = MMCF_AARCH32;                      \
         set_thread_flag(TIF_32BIT);                                     \
  })
 #define COMPAT_ARCH_DLINFO
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index aa04b733b349..2eca178bc943 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -60,6 +60,9 @@ struct thread_info {
 #define thread_saved_fp(tsk)    \
         ((unsigned long)(tsk->thread.cpu_context.fp))
 
+void arch_setup_new_exec(void);
+#define arch_setup_new_exec     arch_setup_new_exec
+
 #endif
 
 /*
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 85b953dd023a..e6bf19c1dddb 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -414,3 +414,11 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
         else
                 return randomize_page(mm->brk, SZ_1G);
 }
+
+/*
+ * Called from setup_new_exec() after (COMPAT_)SET_PERSONALITY.
+ */
+void arch_setup_new_exec(void)
+{
+        current->mm->context.flags = is_compat_task() ? MMCF_AARCH32 : 0;
+}