Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:

 - Expose tag address bits in siginfo. The original arm64 ABI did not
   expose any of the bits 63:56 of a tagged address in siginfo. In the
   presence of user ASAN or MTE, this information may be useful. The
   implementation is generic to other architectures supporting tags
   (like SPARC ADI, subject to wiring up the arch code). The user will
   have to opt in via sigaction(SA_EXPOSE_TAGBITS) so that the extra
   bits, if available, become visible in si_addr.

 - Default to 32-bit wide ZONE_DMA. Previously, ZONE_DMA was set to the
   lowest 1GB to cope with the Raspberry Pi 4 limitations, to the
   detriment of other platforms. With these changes, the kernel scans
   the Device Tree dma-ranges and the ACPI IORT information before
   deciding on a smaller ZONE_DMA.

 - Strengthen READ_ONCE() to acquire when CONFIG_LTO=y. When building
   with LTO, there is an increased risk of the compiler converting an
   address dependency headed by a READ_ONCE() invocation into a control
   dependency and consequently allowing for harmful reordering by the
   CPU.

 - Add CPPC FFH support using arm64 AMU counters.

 - set_fs() removal on arm64. This renders the User Access Override
   (UAO) ARMv8 feature unnecessary.

 - Perf updates: PMU driver for the ARM DMC-620 memory controller, sysfs
   identifier file for SMMUv3, stop event counters support for i.MX8MP,
   enable the perf events-based hard lockup detector.

 - Reorganise the kernel VA space slightly so that 52-bit VA
   configurations can use more virtual address space.

 - Improve the robustness of the arm64 memory offline event notifier.

 - Pad the Image header to 64K following the EFI header definition
   updated recently to increase the section alignment to 64K.

 - Support CONFIG_CMDLINE_EXTEND on arm64.

 - Do not use tagged PC in the kernel (TCR_EL1.TBID1==1), freeing up 8
   bits for PtrAuth.

 - Switch to vmapped shadow call stacks.

 - Miscellaneous clean-ups.

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (78 commits)
  perf/imx_ddr: Add system PMU identifier for userspace
  bindings: perf: imx-ddr: add compatible string
  arm64: Fix build failure when HARDLOCKUP_DETECTOR_PERF is enabled
  arm64: mte: fix prctl(PR_GET_TAGGED_ADDR_CTRL) if TCF0=NONE
  arm64: mark __system_matches_cap as __maybe_unused
  arm64: uaccess: remove vestigal UAO support
  arm64: uaccess: remove redundant PAN toggling
  arm64: uaccess: remove addr_limit_user_check()
  arm64: uaccess: remove set_fs()
  arm64: uaccess cleanup macro naming
  arm64: uaccess: split user/kernel routines
  arm64: uaccess: refactor __{get,put}_user
  arm64: uaccess: simplify __copy_user_flushcache()
  arm64: uaccess: rename privileged uaccess routines
  arm64: sdei: explicitly simulate PAN/UAO entry
  arm64: sdei: move uaccess logic to arch/arm64/
  arm64: head.S: always initialize PSTATE
  arm64: head.S: cleanup SCTLR_ELx initialization
  arm64: head.S: rename el2_setup -> init_kernel_el
  arm64: add C wrappers for SET_PSTATE_*()
  ...

1 files changed, 75 insertions, 103 deletions

diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 991dd5f031e4..abb31aa1f8ca 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -24,44 +24,18 @@
 #include <asm/memory.h>
 #include <asm/extable.h>
 
-#define get_fs()	(current_thread_info()->addr_limit)
-
-static inline void set_fs(mm_segment_t fs)
-{
-	current_thread_info()->addr_limit = fs;
-
-	/*
-	 * Prevent a mispredicted conditional call to set_fs from forwarding
-	 * the wrong address limit to access_ok under speculation.
-	 */
-	spec_bar();
-
-	/* On user-mode return, check fs is correct */
-	set_thread_flag(TIF_FSCHECK);
-
-	/*
-	 * Enable/disable UAO so that copy_to_user() etc can access
-	 * kernel memory with the unprivileged instructions.
-	 */
-	if (IS_ENABLED(CONFIG_ARM64_UAO) && fs == KERNEL_DS)
-		asm(ALTERNATIVE("nop", SET_PSTATE_UAO(1), ARM64_HAS_UAO));
-	else
-		asm(ALTERNATIVE("nop", SET_PSTATE_UAO(0), ARM64_HAS_UAO,
-				CONFIG_ARM64_UAO));
-}
-
-#define uaccess_kernel()	(get_fs() == KERNEL_DS)
+#define HAVE_GET_KERNEL_NOFAULT
 
 /*
  * Test whether a block of memory is a valid user space address.
  * Returns 1 if the range is valid, 0 otherwise.
  *
  * This is equivalent to the following test:
- * (u65)addr + (u65)size <= (u65)current->addr_limit + 1
+ * (u65)addr + (u65)size <= (u65)TASK_SIZE_MAX
  */
 static inline unsigned long __range_ok(const void __user *addr, unsigned long size)
 {
-	unsigned long ret, limit = current_thread_info()->addr_limit;
+	unsigned long ret, limit = TASK_SIZE_MAX - 1;
 
 	/*
 	 * Asynchronous I/O running in a kernel thread does not have the
@@ -94,7 +68,6 @@ static inline unsigned long __range_ok(const void __user *addr, unsigned long si
 }
 
 #define access_ok(addr, size)	__range_ok(addr, size)
-#define user_addr_max			get_fs
 
 #define _ASM_EXTABLE(from, to)						\
 	"	.pushsection	__ex_table, \"a\"\n"			\
@@ -113,8 +86,8 @@ static inline void __uaccess_ttbr0_disable(void)
 	local_irq_save(flags);
 	ttbr = read_sysreg(ttbr1_el1);
 	ttbr &= ~TTBR_ASID_MASK;
-	/* reserved_ttbr0 placed before swapper_pg_dir */
-	write_sysreg(ttbr - RESERVED_TTBR0_SIZE, ttbr0_el1);
+	/* reserved_pg_dir placed before swapper_pg_dir */
+	write_sysreg(ttbr - PAGE_SIZE, ttbr0_el1);
 	isb();
 	/* Set reserved ASID */
 	write_sysreg(ttbr, ttbr1_el1);
@@ -186,47 +159,26 @@ static inline void __uaccess_enable_hw_pan(void)
 			CONFIG_ARM64_PAN));
 }
 
-#define __uaccess_disable(alt)						\
-do {									\
-	if (!uaccess_ttbr0_disable())					\
-		asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), alt,		\
-				CONFIG_ARM64_PAN));			\
-} while (0)
-
-#define __uaccess_enable(alt)						\
-do {									\
-	if (!uaccess_ttbr0_enable())					\
-		asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), alt,		\
-				CONFIG_ARM64_PAN));			\
-} while (0)
-
-static inline void uaccess_disable(void)
+static inline void uaccess_disable_privileged(void)
 {
-	__uaccess_disable(ARM64_HAS_PAN);
-}
+	if (uaccess_ttbr0_disable())
+		return;
 
-static inline void uaccess_enable(void)
-{
-	__uaccess_enable(ARM64_HAS_PAN);
+	__uaccess_enable_hw_pan();
 }
 
-/*
- * These functions are no-ops when UAO is present.
- */
-static inline void uaccess_disable_not_uao(void)
+static inline void uaccess_enable_privileged(void)
 {
-	__uaccess_disable(ARM64_ALT_PAN_NOT_UAO);
-}
+	if (uaccess_ttbr0_enable())
+		return;
 
-static inline void uaccess_enable_not_uao(void)
-{
-	__uaccess_enable(ARM64_ALT_PAN_NOT_UAO);
+	__uaccess_disable_hw_pan();
 }
 
 /*
- * Sanitise a uaccess pointer such that it becomes NULL if above the
- * current addr_limit. In case the pointer is tagged (has the top byte set),
- * untag the pointer before checking.
+ * Sanitise a uaccess pointer such that it becomes NULL if above the maximum
+ * user address. In case the pointer is tagged (has the top byte set), untag
+ * the pointer before checking.
  */
 #define uaccess_mask_ptr(ptr) (__typeof__(ptr))__uaccess_mask_ptr(ptr)
 static inline void __user *__uaccess_mask_ptr(const void __user *ptr)
@@ -237,7 +189,7 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr)
 	"	bics	xzr, %3, %2\n"
 	"	csel	%0, %1, xzr, eq\n"
 	: "=&r" (safe_ptr)
-	: "r" (ptr), "r" (current_thread_info()->addr_limit),
+	: "r" (ptr), "r" (TASK_SIZE_MAX - 1),
 	  "r" (untagged_addr(ptr))
 	: "cc");
 
@@ -253,10 +205,9 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr)
  * The "__xxx_error" versions set the third argument to -EFAULT if an error
  * occurs, and leave it unchanged on success.
  */
-#define __get_user_asm(instr, alt_instr, reg, x, addr, err, feature)	\
+#define __get_mem_asm(load, reg, x, addr, err)				\
 	asm volatile(							\
-	"1:"ALTERNATIVE(instr "     " reg "1, [%2]\n",			\
-			alt_instr " " reg "1, [%2]\n", feature)		\
+	"1:	" load "	" reg "1, [%2]\n"			\
 	"2:\n"								\
 	"	.section .fixup, \"ax\"\n"				\
 	"	.align	2\n"						\
@@ -268,35 +219,36 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr)
 	: "+r" (err), "=&r" (x)						\
 	: "r" (addr), "i" (-EFAULT))
 
-#define __raw_get_user(x, ptr, err)					\
+#define __raw_get_mem(ldr, x, ptr, err)					\
 do {									\
 	unsigned long __gu_val;						\
-	__chk_user_ptr(ptr);						\
-	uaccess_enable_not_uao();					\
 	switch (sizeof(*(ptr))) {					\
 	case 1:								\
-		__get_user_asm("ldrb", "ldtrb", "%w", __gu_val, (ptr),  \
-			       (err), ARM64_HAS_UAO);			\
+		__get_mem_asm(ldr "b", "%w", __gu_val, (ptr), (err));	\
 		break;							\
 	case 2:								\
-		__get_user_asm("ldrh", "ldtrh", "%w", __gu_val, (ptr),  \
-			       (err), ARM64_HAS_UAO);			\
+		__get_mem_asm(ldr "h", "%w", __gu_val, (ptr), (err));	\
 		break;							\
 	case 4:								\
-		__get_user_asm("ldr", "ldtr", "%w", __gu_val, (ptr),	\
-			       (err), ARM64_HAS_UAO);			\
+		__get_mem_asm(ldr, "%w", __gu_val, (ptr), (err));	\
 		break;							\
 	case 8:								\
-		__get_user_asm("ldr", "ldtr", "%x",  __gu_val, (ptr),	\
-			       (err), ARM64_HAS_UAO);			\
+		__get_mem_asm(ldr, "%x",  __gu_val, (ptr), (err));	\
 		break;							\
 	default:							\
 		BUILD_BUG();						\
 	}								\
-	uaccess_disable_not_uao();					\
 	(x) = (__force __typeof__(*(ptr)))__gu_val;			\
 } while (0)
 
+#define __raw_get_user(x, ptr, err)					\
+do {									\
+	__chk_user_ptr(ptr);						\
+	uaccess_ttbr0_enable();						\
+	__raw_get_mem("ldtr", x, ptr, err);				\
+	uaccess_ttbr0_disable();					\
+} while (0)
+
 #define __get_user_error(x, ptr, err)					\
 do {									\
 	__typeof__(*(ptr)) __user *__p = (ptr);				\
@@ -318,10 +270,19 @@ do {									\
 
 #define get_user	__get_user
 
-#define __put_user_asm(instr, alt_instr, reg, x, addr, err, feature)	\
+#define __get_kernel_nofault(dst, src, type, err_label)			\
+do {									\
+	int __gkn_err = 0;						\
+									\
+	__raw_get_mem("ldr", *((type *)(dst)),				\
+		      (__force type *)(src), __gkn_err);		\
+	if (unlikely(__gkn_err))					\
+		goto err_label;						\
+} while (0)
+
+#define __put_mem_asm(store, reg, x, addr, err)				\
 	asm volatile(							\
-	"1:"ALTERNATIVE(instr "     " reg "1, [%2]\n",			\
-			alt_instr " " reg "1, [%2]\n", feature)		\
+	"1:	" store "	" reg "1, [%2]\n"			\
 	"2:\n"								\
 	"	.section .fixup,\"ax\"\n"				\
 	"	.align	2\n"						\
@@ -332,32 +293,33 @@ do {									\
 	: "+r" (err)							\
 	: "r" (x), "r" (addr), "i" (-EFAULT))
 
-#define __raw_put_user(x, ptr, err)					\
+#define __raw_put_mem(str, x, ptr, err)					\
 do {									\
 	__typeof__(*(ptr)) __pu_val = (x);				\
-	__chk_user_ptr(ptr);						\
-	uaccess_enable_not_uao();					\
 	switch (sizeof(*(ptr))) {					\
 	case 1:								\
-		__put_user_asm("strb", "sttrb", "%w", __pu_val, (ptr),	\
-			       (err), ARM64_HAS_UAO);			\
+		__put_mem_asm(str "b", "%w", __pu_val, (ptr), (err));	\
 		break;							\
 	case 2:								\
-		__put_user_asm("strh", "sttrh", "%w", __pu_val, (ptr),	\
-			       (err), ARM64_HAS_UAO);			\
+		__put_mem_asm(str "h", "%w", __pu_val, (ptr), (err));	\
 		break;							\
 	case 4:								\
-		__put_user_asm("str", "sttr", "%w", __pu_val, (ptr),	\
-			       (err), ARM64_HAS_UAO);			\
+		__put_mem_asm(str, "%w", __pu_val, (ptr), (err));	\
 		break;							\
 	case 8:								\
-		__put_user_asm("str", "sttr", "%x", __pu_val, (ptr),	\
-			       (err), ARM64_HAS_UAO);			\
+		__put_mem_asm(str, "%x", __pu_val, (ptr), (err));	\
 		break;							\
 	default:							\
 		BUILD_BUG();						\
 	}								\
-	uaccess_disable_not_uao();					\
+} while (0)
+
+#define __raw_put_user(x, ptr, err)					\
+do {									\
+	__chk_user_ptr(ptr);						\
+	uaccess_ttbr0_enable();						\
+	__raw_put_mem("sttr", x, ptr, err);				\
+	uaccess_ttbr0_disable();					\
 } while (0)
 
 #define __put_user_error(x, ptr, err)					\
@@ -381,14 +343,24 @@ do {									\
 
 #define put_user	__put_user
 
+#define __put_kernel_nofault(dst, src, type, err_label)			\
+do {									\
+	int __pkn_err = 0;						\
+									\
+	__raw_put_mem("str", *((type *)(src)),				\
+		      (__force type *)(dst), __pkn_err);		\
+	if (unlikely(__pkn_err))					\
+		goto err_label;						\
+} while(0)
+
 extern unsigned long __must_check __arch_copy_from_user(void *to, const void __user *from, unsigned long n);
 #define raw_copy_from_user(to, from, n)					\
 ({									\
 	unsigned long __acfu_ret;					\
-	uaccess_enable_not_uao();					\
+	uaccess_ttbr0_enable();						\
 	__acfu_ret = __arch_copy_from_user((to),			\
 				      __uaccess_mask_ptr(from), (n));	\
-	uaccess_disable_not_uao();					\
+	uaccess_ttbr0_disable();					\
 	__acfu_ret;							\
 })
 
@@ -396,10 +368,10 @@ extern unsigned long __must_check __arch_copy_to_user(void __user *to, const voi
 #define raw_copy_to_user(to, from, n)					\
 ({									\
 	unsigned long __actu_ret;					\
-	uaccess_enable_not_uao();					\
+	uaccess_ttbr0_enable();						\
 	__actu_ret = __arch_copy_to_user(__uaccess_mask_ptr(to),	\
 				    (from), (n));			\
-	uaccess_disable_not_uao();					\
+	uaccess_ttbr0_disable();					\
 	__actu_ret;							\
 })
 
@@ -407,10 +379,10 @@ extern unsigned long __must_check __arch_copy_in_user(void __user *to, const voi
 #define raw_copy_in_user(to, from, n)					\
 ({									\
 	unsigned long __aciu_ret;					\
-	uaccess_enable_not_uao();					\
+	uaccess_ttbr0_enable();						\
 	__aciu_ret = __arch_copy_in_user(__uaccess_mask_ptr(to),	\
 				    __uaccess_mask_ptr(from), (n));	\
-	uaccess_disable_not_uao();					\
+	uaccess_ttbr0_disable();					\
 	__aciu_ret;							\
 })
 
@@ -421,9 +393,9 @@ extern unsigned long __must_check __arch_clear_user(void __user *to, unsigned lo
 static inline unsigned long __must_check __clear_user(void __user *to, unsigned long n)
 {
 	if (access_ok(to, n)) {
-		uaccess_enable_not_uao();
+		uaccess_ttbr0_enable();
 		n = __arch_clear_user(__uaccess_mask_ptr(to), n);
-		uaccess_disable_not_uao();
+		uaccess_ttbr0_disable();
 	}
 	return n;
 }