Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

Pull ARM fixes from Russell King:
 "Two fixes for 6.1:

   - fix stacktraces for tracepoint events in Thumb2 mode

   - fix for noMMU ZERO_PAGE() implementation"

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 9266/1: mm: fix no-MMU ZERO_PAGE() implementation
  ARM: 9251/1: perf: Fix stacktraces for tracepoint events in THUMB2 kernels

Author: torvalds

arch/arm/include/asm/perf_event.h

@@ -17,7 +17,7 @@ extern unsigned long perf_misc_flags(struct pt_regs *regs);
 
 #define perf_arch_fetch_caller_regs(regs, __ip) { \
 	(regs)->ARM_pc = (__ip); \
-	(regs)->ARM_fp = (unsigned long) __builtin_frame_address(0); \
+	frame_pointer((regs)) = (unsigned long) __builtin_frame_address(0); \
 	(regs)->ARM_sp = current_stack_pointer; \
 	(regs)->ARM_cpsr = SVC_MODE; \
 }

arch/arm/include/asm/pgtable-nommu.h

@@ -44,12 +44,6 @@
 
 typedef pte_t *pte_addr_t;
 
-/*
- * ZERO_PAGE is a global shared page that is always zero: used
- * for zero-mapped memory areas etc..
- */
-#define ZERO_PAGE(vaddr)	(virt_to_page(0))
-
 /*
  * Mark the prot value as uncacheable and unbufferable.
  */

arch/arm/include/asm/pgtable.h

@@ -10,6 +10,15 @@
 #include <linux/const.h>
 #include <asm/proc-fns.h>
 
+#ifndef __ASSEMBLY__
+/*
+ * ZERO_PAGE is a global shared page that is always zero: used
+ * for zero-mapped memory areas etc..
+ */
+extern struct page *empty_zero_page;
+#define ZERO_PAGE(vaddr)	(empty_zero_page)
+#endif
+
 #ifndef CONFIG_MMU
 
 #include <asm-generic/pgtable-nopud.h>
@@ -139,13 +148,6 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
  */
 
 #ifndef __ASSEMBLY__
-/*
- * ZERO_PAGE is a global shared page that is always zero: used
- * for zero-mapped memory areas etc..
- */
-extern struct page *empty_zero_page;
-#define ZERO_PAGE(vaddr)	(empty_zero_page)
-
 
 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 

arch/arm/mm/nommu.c

@@ -26,6 +26,13 @@
 
 unsigned long vectors_base;
 
+/*
+ * empty_zero_page is a special page that is used for
+ * zero-initialized data and COW.
+ */
+struct page *empty_zero_page;
+EXPORT_SYMBOL(empty_zero_page);
+
 #ifdef CONFIG_ARM_MPU
 struct mpu_rgn_info mpu_rgn_info;
 #endif
@@ -148,9 +155,21 @@ void __init adjust_lowmem_bounds(void)
  */
 void __init paging_init(const struct machine_desc *mdesc)
 {
+	void *zero_page;
+
 	early_trap_init((void *)vectors_base);
 	mpu_setup();
+
+	/* allocate the zero page. */
+	zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+	if (!zero_page)
+		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+		      __func__, PAGE_SIZE, PAGE_SIZE);
+
 	bootmem_init();
+
+	empty_zero_page = virt_to_page(zero_page);
+	flush_dcache_page(empty_zero_page);
 }
 
 /*