Add a helper that generates a short snippet of code that updates PIE
relocations, loads the stack pointer and calls a C (or asm) function.
The code gets placed into a PIE section.
Signed-off-by: Russ Dill <Russ.Dill@xxxxxx>
---
arch/arm/include/asm/suspend.h | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)
diff --git a/arch/arm/include/asm/suspend.h b/arch/arm/include/asm/suspend.h
index cd20029..92996f0 100644
--- a/arch/arm/include/asm/suspend.h
+++ b/arch/arm/include/asm/suspend.h
@@ -1,6 +1,8 @@
#ifndef __ASM_ARM_SUSPEND_H
#define __ASM_ARM_SUSPEND_H
+#include <asm/pie.h>
+
struct sleep_save_sp {
u32 *save_ptr_stash;
u32 save_ptr_stash_phys;
@@ -9,4 +11,27 @@ struct sleep_save_sp {
extern void cpu_resume(void);
extern int cpu_suspend(unsigned long, int (*)(unsigned long));
+/**
+ * ARM_PIE_RESUME - generate a PIE trampoline for resume
+ * @proc: SoC, should match argument used with PIE_OVERLAY_SECTION()
+ * @func: C or asm function to call at resume
+ * @stack: stack to use before calling func
+ */
+#define ARM_PIE_RESUME(proc, func, stack) \
+static void __naked __noreturn __pie(proc) proc##_resume_trampoline2(void) \
+{ \
+ __asm__ __volatile__( \
+ " mov sp, %0\n" \
+ : : "r"((stack)) : "sp"); \
+ \
+ func(); \
+} \
+ \
+void __naked __noreturn __pie(proc) proc##_resume_trampoline(void) \
+{ \
+ pie_relocate_from_pie(); \
+ proc##_resume_trampoline2(); \
+} \
+EXPORT_PIE_SYMBOL(proc##_resume_trampoline)
+
#endif
--
1.8.3.2
--
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