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

Pull ARM development updates from Russell King:

 - Make it clear __swp_entry_to_pte() uses PTE_TYPE_FAULT

 - Updates for setting vmalloc size via command line to resolve an issue
   with the 8MiB hole not properly being accounted for, and clean up the
   code.

 - ftrace support for module PLTs

 - Spelling fixes

 - kbuild updates for removing generated files and pattern rules for
   generating files

 - Clang/llvm updates

 - Change the way the kernel is mapped, placing it in vmalloc space
   instead.

 - Remove arm_pm_restart from arm and aarch64.

* tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (29 commits)
  ARM: 9098/1: ftrace: MODULE_PLT: Fix build problem without DYNAMIC_FTRACE
  ARM: 9097/1: mmu: Declare section start/end correctly
  ARM: 9096/1: Remove arm_pm_restart()
  ARM: 9095/1: ARM64: Remove arm_pm_restart()
  ARM: 9094/1: Register with kernel restart handler
  ARM: 9093/1: drivers: firmwapsci: Register with kernel restart handler
  ARM: 9092/1: xen: Register with kernel restart handler
  ARM: 9091/1: Revert "mm: qsd8x50: Fix incorrect permission faults"
  ARM: 9090/1: Map the lowmem and kernel separately
  ARM: 9089/1: Define kernel physical section start and end
  ARM: 9088/1: Split KERNEL_OFFSET from PAGE_OFFSET
  ARM: 9087/1: kprobes: test-thumb: fix for LLVM_IAS=1
  ARM: 9086/1: syscalls: use pattern rules to generate syscall headers
  ARM: 9085/1: remove unneeded abi parameter to syscallnr.sh
  ARM: 9084/1: simplify the build rule of mach-types.h
  ARM: 9083/1: uncompress: atags_to_fdt: Spelling s/REturn/Return/
  ARM: 9082/1: [v2] mark prepare_page_table as __init
  ARM: 9079/1: ftrace: Add MODULE_PLTS support
  ARM: 9078/1: Add warn suppress parameter to arm_gen_branch_link()
  ARM: 9077/1: PLT: Move struct plt_entries definition to header
  ...

Author: torvalds

arch/arm/Kconfig.debug

@@ -66,6 +66,8 @@ config UNWINDER_FRAME_POINTER
 config UNWINDER_ARM
 	bool "ARM EABI stack unwinder"
 	depends on AEABI && !FUNCTION_GRAPH_TRACER
+	# https://github.com/ClangBuiltLinux/linux/issues/732
+	depends on !LD_IS_LLD || LLD_VERSION >= 110000
 	select ARM_UNWIND
 	help
 	  This option enables stack unwinding support in the kernel

arch/arm/boot/compressed/Makefile

@@ -100,7 +100,7 @@ targets       := vmlinux vmlinux.lds piggy_data piggy.o \
 		 lib1funcs.o ashldi3.o bswapsdi2.o \
 		 head.o $(OBJS)
 
-clean-files += piggy_data lib1funcs.S ashldi3.S bswapsdi2.S hyp-stub.S
+clean-files += lib1funcs.S ashldi3.S bswapsdi2.S hyp-stub.S
 
 KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
 

arch/arm/boot/compressed/atags_to_fdt.c

@@ -121,7 +121,7 @@ static void hex_str(char *out, uint32_t value)
 /*
  * Convert and fold provided ATAGs into the provided FDT.
  *
- * REturn values:
+ * Return values:
  *    = 0 -> pretend success
  *    = 1 -> bad ATAG (may retry with another possible ATAG pointer)
  *    < 0 -> error from libfdt

arch/arm/include/asm/ftrace.h

@@ -15,6 +15,9 @@ extern void __gnu_mcount_nc(void);
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 struct dyn_arch_ftrace {
+#ifdef CONFIG_ARM_MODULE_PLTS
+	struct module *mod;
+#endif
 };
 
 static inline unsigned long ftrace_call_adjust(unsigned long addr)

arch/arm/include/asm/insn.h

@@ -13,18 +13,18 @@ arm_gen_nop(void)
 }
 
 unsigned long
-__arm_gen_branch(unsigned long pc, unsigned long addr, bool link);
+__arm_gen_branch(unsigned long pc, unsigned long addr, bool link, bool warn);
 
 static inline unsigned long
 arm_gen_branch(unsigned long pc, unsigned long addr)
 {
-	return __arm_gen_branch(pc, addr, false);
+	return __arm_gen_branch(pc, addr, false, true);
 }
 
 static inline unsigned long
-arm_gen_branch_link(unsigned long pc, unsigned long addr)
+arm_gen_branch_link(unsigned long pc, unsigned long addr, bool warn)
 {
-	return __arm_gen_branch(pc, addr, true);
+	return __arm_gen_branch(pc, addr, true, warn);
 }
 
 #endif

arch/arm/include/asm/memory.h

@@ -20,8 +20,14 @@
 #endif
 #include <asm/kasan_def.h>
 
-/* PAGE_OFFSET - the virtual address of the start of the kernel image */
+/*
+ * PAGE_OFFSET: the virtual address of the start of lowmem, memory above
+ *   the virtual address range for userspace.
+ * KERNEL_OFFSET: the virtual address of the start of the kernel image.
+ *   we may further offset this with TEXT_OFFSET in practice.
+ */
 #define PAGE_OFFSET		UL(CONFIG_PAGE_OFFSET)
+#define KERNEL_OFFSET		(PAGE_OFFSET)
 
 #ifdef CONFIG_MMU
 
@@ -152,6 +158,13 @@ extern unsigned long vectors_base;
 
 #ifndef __ASSEMBLY__
 
+/*
+ * Physical start and end address of the kernel sections. These addresses are
+ * 2MB-aligned to match the section mappings placed over the kernel.
+ */
+extern u32 kernel_sec_start;
+extern u32 kernel_sec_end;
+
 /*
  * Physical vs virtual RAM address space conversion.  These are
  * private definitions which should NOT be used outside memory.h

arch/arm/include/asm/module.h

@@ -19,8 +19,18 @@ enum {
 };
 #endif
 
+#define PLT_ENT_STRIDE		L1_CACHE_BYTES
+#define PLT_ENT_COUNT		(PLT_ENT_STRIDE / sizeof(u32))
+#define PLT_ENT_SIZE		(sizeof(struct plt_entries) / PLT_ENT_COUNT)
+
+struct plt_entries {
+	u32	ldr[PLT_ENT_COUNT];
+	u32	lit[PLT_ENT_COUNT];
+};
+
 struct mod_plt_sec {
 	struct elf32_shdr	*plt;
+	struct plt_entries	*plt_ent;
 	int			plt_count;
 };
 

arch/arm/include/asm/pgtable.h

@@ -306,7 +306,7 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
 
 #define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
-#define __swp_entry_to_pte(swp)	((pte_t) { (swp).val })
+#define __swp_entry_to_pte(swp)	__pte((swp).val | PTE_TYPE_FAULT)
 
 /*
  * It is an error for the kernel to have more swap files than we can

arch/arm/include/asm/system_misc.h

@@ -13,7 +13,6 @@
 extern void cpu_init(void);
 
 void soft_restart(unsigned long);
-extern void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
 extern void (*arm_pm_idle)(void);
 
 #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR

arch/arm/kernel/ftrace.c

@@ -68,9 +68,10 @@ int ftrace_arch_code_modify_post_process(void)
 	return 0;
 }
 
-static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr)
+static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr,
+					 bool warn)
 {
-	return arm_gen_branch_link(pc, addr);
+	return arm_gen_branch_link(pc, addr, warn);
 }
 
 static int ftrace_modify_code(unsigned long pc, unsigned long old,
@@ -104,14 +105,14 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
 	int ret;
 
 	pc = (unsigned long)&ftrace_call;
-	new = ftrace_call_replace(pc, (unsigned long)func);
+	new = ftrace_call_replace(pc, (unsigned long)func, true);
 
 	ret = ftrace_modify_code(pc, 0, new, false);
 
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 	if (!ret) {
 		pc = (unsigned long)&ftrace_regs_call;
-		new = ftrace_call_replace(pc, (unsigned long)func);
+		new = ftrace_call_replace(pc, (unsigned long)func, true);
 
 		ret = ftrace_modify_code(pc, 0, new, false);
 	}
@@ -124,10 +125,22 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 {
 	unsigned long new, old;
 	unsigned long ip = rec->ip;
+	unsigned long aaddr = adjust_address(rec, addr);
+	struct module *mod = NULL;
+
+#ifdef CONFIG_ARM_MODULE_PLTS
+	mod = rec->arch.mod;
+#endif
 
 	old = ftrace_nop_replace(rec);
 
-	new = ftrace_call_replace(ip, adjust_address(rec, addr));
+	new = ftrace_call_replace(ip, aaddr, !mod);
+#ifdef CONFIG_ARM_MODULE_PLTS
+	if (!new && mod) {
+		aaddr = get_module_plt(mod, ip, aaddr);
+		new = ftrace_call_replace(ip, aaddr, true);
+	}
+#endif
 
 	return ftrace_modify_code(rec->ip, old, new, true);
 }
@@ -140,9 +153,9 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 	unsigned long new, old;
 	unsigned long ip = rec->ip;
 
-	old = ftrace_call_replace(ip, adjust_address(rec, old_addr));
+	old = ftrace_call_replace(ip, adjust_address(rec, old_addr), true);
 
-	new = ftrace_call_replace(ip, adjust_address(rec, addr));
+	new = ftrace_call_replace(ip, adjust_address(rec, addr), true);
 
 	return ftrace_modify_code(rec->ip, old, new, true);
 }
@@ -152,12 +165,29 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 int ftrace_make_nop(struct module *mod,
 		    struct dyn_ftrace *rec, unsigned long addr)
 {
+	unsigned long aaddr = adjust_address(rec, addr);
 	unsigned long ip = rec->ip;
 	unsigned long old;
 	unsigned long new;
 	int ret;
 
-	old = ftrace_call_replace(ip, adjust_address(rec, addr));
+#ifdef CONFIG_ARM_MODULE_PLTS
+	/* mod is only supplied during module loading */
+	if (!mod)
+		mod = rec->arch.mod;
+	else
+		rec->arch.mod = mod;
+#endif
+
+	old = ftrace_call_replace(ip, aaddr,
+				  !IS_ENABLED(CONFIG_ARM_MODULE_PLTS) || !mod);
+#ifdef CONFIG_ARM_MODULE_PLTS
+	if (!old && mod) {
+		aaddr = get_module_plt(mod, ip, aaddr);
+		old = ftrace_call_replace(ip, aaddr, true);
+	}
+#endif
+
 	new = ftrace_nop_replace(rec);
 	ret = ftrace_modify_code(ip, old, new, true);
 

arch/arm/kernel/head.S

@@ -23,15 +23,14 @@
 #if defined(CONFIG_DEBUG_LL) && !defined(CONFIG_DEBUG_SEMIHOSTING)
 #include CONFIG_DEBUG_LL_INCLUDE
 #endif
-
 /*
  * swapper_pg_dir is the virtual address of the initial page table.
  * We place the page tables 16K below KERNEL_RAM_VADDR.  Therefore, we must
  * make sure that KERNEL_RAM_VADDR is correctly set.  Currently, we expect
  * the least significant 16 bits to be 0x8000, but we could probably
  * relax this restriction to KERNEL_RAM_VADDR >= PAGE_OFFSET + 0x4000.
  */
-#define KERNEL_RAM_VADDR	(PAGE_OFFSET + TEXT_OFFSET)
+#define KERNEL_RAM_VADDR	(KERNEL_OFFSET + TEXT_OFFSET)
 #if (KERNEL_RAM_VADDR & 0xffff) != 0x8000
 #error KERNEL_RAM_VADDR must start at 0xXXXX8000
 #endif
@@ -48,6 +47,20 @@
 	.globl	swapper_pg_dir
 	.equ	swapper_pg_dir, KERNEL_RAM_VADDR - PG_DIR_SIZE
 
+	/*
+	 * This needs to be assigned at runtime when the linker symbols are
+	 * resolved.
+	 */
+	.pushsection .data
+	.align	2
+	.globl	kernel_sec_start
+	.globl	kernel_sec_end
+kernel_sec_start:
+	.long	0
+kernel_sec_end:
+	.long	0
+	.popsection
+
 	.macro	pgtbl, rd, phys
 	add	\rd, \phys, #TEXT_OFFSET
 	sub	\rd, \rd, #PG_DIR_SIZE
@@ -230,16 +243,23 @@ __create_page_tables:
 	blo	1b
 
 	/*
-	 * Map our RAM from the start to the end of the kernel .bss section.
+	 * The main matter: map in the kernel using section mappings, and
+	 * set two variables to indicate the physical start and end of the
+	 * kernel.
 	 */
-	add	r0, r4, #PAGE_OFFSET >> (SECTION_SHIFT - PMD_ORDER)
+	add	r0, r4, #KERNEL_OFFSET >> (SECTION_SHIFT - PMD_ORDER)
 	ldr	r6, =(_end - 1)
-	orr	r3, r8, r7
+	adr_l	r5, kernel_sec_start		@ _pa(kernel_sec_start)
+	str	r8, [r5]			@ Save physical start of kernel
+	orr	r3, r8, r7			@ Add the MMU flags
 	add	r6, r4, r6, lsr #(SECTION_SHIFT - PMD_ORDER)
 1:	str	r3, [r0], #1 << PMD_ORDER
 	add	r3, r3, #1 << SECTION_SHIFT
 	cmp	r0, r6
 	bls	1b
+	eor	r3, r3, r7			@ Remove the MMU flags
+	adr_l	r5, kernel_sec_end		@ _pa(kernel_sec_end)
+	str	r3, [r5]			@ Save physical end of kernel
 
 #ifdef CONFIG_XIP_KERNEL
 	/*

arch/arm/kernel/insn.c

@@ -3,16 +3,17 @@
 #include <linux/kernel.h>
 #include <asm/opcodes.h>
 
-static unsigned long
-__arm_gen_branch_thumb2(unsigned long pc, unsigned long addr, bool link)
+static unsigned long __arm_gen_branch_thumb2(unsigned long pc,
+					     unsigned long addr, bool link,
+					     bool warn)
 {
 	unsigned long s, j1, j2, i1, i2, imm10, imm11;
 	unsigned long first, second;
 	long offset;
 
 	offset = (long)addr - (long)(pc + 4);
 	if (offset < -16777216 || offset > 16777214) {
-		WARN_ON_ONCE(1);
+		WARN_ON_ONCE(warn);
 		return 0;
 	}
 
@@ -33,8 +34,8 @@ __arm_gen_branch_thumb2(unsigned long pc, unsigned long addr, bool link)
 	return __opcode_thumb32_compose(first, second);
 }
 
-static unsigned long
-__arm_gen_branch_arm(unsigned long pc, unsigned long addr, bool link)
+static unsigned long __arm_gen_branch_arm(unsigned long pc, unsigned long addr,
+					  bool link, bool warn)
 {
 	unsigned long opcode = 0xea000000;
 	long offset;
@@ -44,7 +45,7 @@ __arm_gen_branch_arm(unsigned long pc, unsigned long addr, bool link)
 
 	offset = (long)addr - (long)(pc + 8);
 	if (unlikely(offset < -33554432 || offset > 33554428)) {
-		WARN_ON_ONCE(1);
+		WARN_ON_ONCE(warn);
 		return 0;
 	}
 
@@ -54,10 +55,10 @@ __arm_gen_branch_arm(unsigned long pc, unsigned long addr, bool link)
 }
 
 unsigned long
-__arm_gen_branch(unsigned long pc, unsigned long addr, bool link)
+__arm_gen_branch(unsigned long pc, unsigned long addr, bool link, bool warn)
 {
 	if (IS_ENABLED(CONFIG_THUMB2_KERNEL))
-		return __arm_gen_branch_thumb2(pc, addr, link);
+		return __arm_gen_branch_thumb2(pc, addr, link, warn);
 	else
-		return __arm_gen_branch_arm(pc, addr, link);
+		return __arm_gen_branch_arm(pc, addr, link, warn);
 }