Merge branch 'v4.4/topic/mm-kaslr' into v4.4/topic/mm-kaslr-pax_usercopy

Author: Alex Shi

arch/arm64/Kconfig

@@ -751,7 +751,7 @@ config RELOCATABLE
 
 config RANDOMIZE_BASE
 	bool "Randomize the address of the kernel image"
-	select ARM64_MODULE_PLTS
+	select ARM64_MODULE_PLTS if MODULES
 	select RELOCATABLE
 	help
 	  Randomizes the virtual address at which the kernel image is

arch/arm64/Kconfig.debug

@@ -64,13 +64,13 @@ config DEBUG_SET_MODULE_RONX
 
 config DEBUG_RODATA
 	bool "Make kernel text and rodata read-only"
+	default y
 	help
 	  If this is set, kernel text and rodata will be made read-only. This
 	  is to help catch accidental or malicious attempts to change the
-	  kernel's executable code. Additionally splits rodata from kernel
-	  text so it can be made explicitly non-executable.
+	  kernel's executable code.
 
-          If in doubt, say Y
+	  If in doubt, say Y
 
 config DEBUG_ALIGN_RODATA
 	depends on DEBUG_RODATA

arch/arm64/Makefile

@@ -60,7 +60,9 @@ head-y		:= arch/arm64/kernel/head.o
 
 # The byte offset of the kernel image in RAM from the start of RAM.
 ifeq ($(CONFIG_ARM64_RANDOMIZE_TEXT_OFFSET), y)
-TEXT_OFFSET := $(shell awk 'BEGIN {srand(); printf "0x%03x000\n", int(512 * rand())}')
+TEXT_OFFSET := $(shell awk "BEGIN {srand(); printf \"0x%06x\n\", \
+		 int(2 * 1024 * 1024 / (2 ^ $(CONFIG_ARM64_PAGE_SHIFT)) * \
+		 rand()) * (2 ^ $(CONFIG_ARM64_PAGE_SHIFT))}")
 else
 TEXT_OFFSET := 0x00080000
 endif

arch/arm64/include/asm/spinlock.h

@@ -31,19 +31,29 @@ static inline void arch_spin_unlock_wait(arch_spinlock_t *lock)
 	unsigned int tmp;
 	arch_spinlock_t lockval;
 
+	/*
+	 * Ensure prior spin_lock operations to other locks have completed
+	 * on this CPU before we test whether "lock" is locked.
+	 */
+	smp_mb();
+
 	asm volatile(
 "	sevl\n"
 "1:	wfe\n"
 "2:	ldaxr	%w0, %2\n"
 "	eor	%w1, %w0, %w0, ror #16\n"
 "	cbnz	%w1, 1b\n"
+	/* Serialise against any concurrent lockers */
 	ARM64_LSE_ATOMIC_INSN(
 	/* LL/SC */
 "	stxr	%w1, %w0, %2\n"
-"	cbnz	%w1, 2b\n", /* Serialise against any concurrent lockers */
-	/* LSE atomics */
 "	nop\n"
-"	nop\n")
+"	nop\n",
+	/* LSE atomics */
+"	mov	%w1, %w0\n"
+"	cas	%w0, %w0, %2\n"
+"	eor	%w1, %w1, %w0\n")
+"	cbnz	%w1, 2b\n"
 	: "=&r" (lockval), "=&r" (tmp), "+Q" (*lock)
 	:
 	: "memory");
@@ -148,6 +158,7 @@ static inline int arch_spin_value_unlocked(arch_spinlock_t lock)
 
 static inline int arch_spin_is_locked(arch_spinlock_t *lock)
 {
+	smp_mb(); /* See arch_spin_unlock_wait */
 	return !arch_spin_value_unlocked(READ_ONCE(*lock));
 }
 

arch/arm64/kernel/head.S

@@ -697,6 +697,9 @@ __enable_mmu:
 	isb
 	bl	__create_page_tables		// recreate kernel mapping
 
+	tlbi	vmalle1				// Remove any stale TLB entries
+	dsb	nsh
+
 	msr	sctlr_el1, x19			// re-enable the MMU
 	isb
 	ic	iallu				// flush instructions fetched

arch/arm64/kernel/traps.c

@@ -64,8 +64,7 @@ static void dump_mem(const char *lvl, const char *str, unsigned long bottom,
 
 	/*
 	 * We need to switch to kernel mode so that we can use __get_user
-	 * to safely read from kernel space.  Note that we now dump the
-	 * code first, just in case the backtrace kills us.
+	 * to safely read from kernel space.
 	 */
 	fs = get_fs();
 	set_fs(KERNEL_DS);
@@ -111,21 +110,12 @@ static void dump_backtrace_entry(unsigned long where)
 	print_ip_sym(where);
 }
 
-static void dump_instr(const char *lvl, struct pt_regs *regs)
+static void __dump_instr(const char *lvl, struct pt_regs *regs)
 {
 	unsigned long addr = instruction_pointer(regs);
-	mm_segment_t fs;
 	char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
 	int i;
 
-	/*
-	 * We need to switch to kernel mode so that we can use __get_user
-	 * to safely read from kernel space.  Note that we now dump the
-	 * code first, just in case the backtrace kills us.
-	 */
-	fs = get_fs();
-	set_fs(KERNEL_DS);
-
 	for (i = -4; i < 1; i++) {
 		unsigned int val, bad;
 
@@ -139,8 +129,18 @@ static void dump_instr(const char *lvl, struct pt_regs *regs)
 		}
 	}
 	printk("%sCode: %s\n", lvl, str);
+}
 
-	set_fs(fs);
+static void dump_instr(const char *lvl, struct pt_regs *regs)
+{
+	if (!user_mode(regs)) {
+		mm_segment_t fs = get_fs();
+		set_fs(KERNEL_DS);
+		__dump_instr(lvl, regs);
+		set_fs(fs);
+	} else {
+		__dump_instr(lvl, regs);
+	}
 }
 
 static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)

drivers/hwtracing/coresight/coresight-tmc.c

@@ -388,9 +388,6 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id)
 err_misc_register:
 	coresight_unregister(drvdata->csdev);
 err_devm_kzalloc:
-	if (drvdata->config_type == TMC_CONFIG_TYPE_ETR)
-		dma_free_coherent(dev, drvdata->size,
-				drvdata->vaddr, drvdata->paddr);
 	return ret;
 }
 

kernel/events/core.c

@@ -5797,7 +5797,7 @@ static int __perf_pmu_output_stop(void *info)
 {
 	struct perf_event *event = info;
 	struct pmu *pmu = event->pmu;
-	struct perf_cpu_context *cpuctx = get_cpu_ptr(pmu->pmu_cpu_context);
+	struct perf_cpu_context *cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
 	struct remote_output ro = {
 		.rb	= event->rb,
 	};