Thread (49 messages) 49 messages, 6 authors, 2014-07-01

[PATCH 10/24] ARM64: Introduce is_a32_task and is_a32_thread. Use them in the correct locations.

From: catalin.marinas@arm.com (Catalin Marinas)
Date: 2014-06-18 17:47:26
Also in: lkml

On Sat, May 24, 2014 at 12:02:05AM -0700, Andrew Pinski wrote:
quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/include/asm/compat.h b/arch/arm64/include/asm/compat.h
index e71f81f..fad7612 100644
--- a/arch/arm64/include/asm/compat.h
+++ b/arch/arm64/include/asm/compat.h
@@ -293,28 +293,47 @@ struct compat_shmid64_ds {
 	compat_ulong_t __unused5;
 };
 
-static inline int is_compat_task(void)
+#ifdef CONFIG_AARCH32_EL0
+static inline int is_a32_compat_task(void)
 {
 	return test_thread_flag(TIF_32BIT);
 }
-
-static inline int is_compat_thread(struct thread_info *thread)
+static inline int is_a32_compat_thread(struct thread_info *thread)
 {
 	return test_ti_thread_flag(thread, TIF_32BIT);
 }
+#else
+static inline int is_a32_compat_task(void)
+{
+	return 0;
+}
+static inline int is_a32_compat_thread(struct thread_info *thread)
+{
+	return 0;
+}
+#endif
 
 #else /* !CONFIG_COMPAT */
 
-static inline int is_compat_task(void)
+static inline int is_a32_compat_task(void)
 {
 	return 0;
 }
-
-static inline int is_compat_thread(struct thread_info *thread)
+static inline int is_a32_compat_thread(struct thread_info *thread)
 {
 	return 0;
 }
Why do we have 2 dummy definitions for is_a32_compat_task()? Could we
not squash them into one with different #ifdefs?
quoted hunk ↗ jump to hunk
 
 #endif /* CONFIG_COMPAT */
+
+static inline int is_compat_task(void)
+{
+	return is_a32_compat_task();
+}
+
+static inline int is_compat_thread(struct thread_info *thread)
+{
+	return is_a32_compat_thread(thread);
+}
 #endif /* __KERNEL__ */
 #endif /* __ASM_COMPAT_H */
diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h
index 36c3603..8180511 100644
--- a/arch/arm64/include/asm/elf.h
+++ b/arch/arm64/include/asm/elf.h
@@ -150,7 +150,7 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm,
 
 /* 1GB of VA */
 #ifdef CONFIG_COMPAT
-#define STACK_RND_MASK			(test_thread_flag(TIF_32BIT) ? \
+#define STACK_RND_MASK			(is_compat_task() ? \
 						0x7ff >> (PAGE_SHIFT - 12) : \
 						0x3ffff >> (PAGE_SHIFT - 12))
I think I tried something similar in the past and while it works most of
the time, you can easily get into an #include mess since now elf.h needs
compat.h. Similarly for other header files where you've changed this.
quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h
index 720e70b..b2bf728 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -106,7 +106,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_FREEZE		19
 #define TIF_RESTORE_SIGMASK	20
 #define TIF_SINGLESTEP		21
-#define TIF_32BIT		22	/* 32bit process */
+#define TIF_32BIT		22	/* AARCH32 process */
Can we not just keep TIF_32BIT for limiting the address space to 32-bit
and use another bit for AArch32 applications?

-- 
Catalin
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