Merge tag 'powerpc-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Enable STRICT_KERNEL_RWX for Freescale 85xx platforms.

 - Activate CONFIG_STRICT_KERNEL_RWX by default, while still allowing it
   to be disabled.

 - Add support for out-of-line static calls on 32-bit.

 - Fix oopses doing bpf-to-bpf calls when STRICT_KERNEL_RWX is enabled.

 - Fix boot hangs on e5500 due to stale value in ESR passed to
   do_page_fault().

 - Fix several bugs on pseries in handling of device tree cache
   information for hotplugged CPUs, and/or during partition migration.

 - Various other small features and fixes.

Thanks to Alexey Kardashevskiy, Alistair Popple, Anatolij Gustschin,
Andrew Donnellan, Athira Rajeev, Bixuan Cui, Bjorn Helgaas, Cédric Le
Goater, Christophe Leroy, Daniel Axtens, Daniel Henrique Barboza, Denis
Kirjanov, Fabiano Rosas, Frederic Barrat, Gustavo A.  R.  Silva, Hari
Bathini, Jacques de Laval, Joel Stanley, Kai Song, Kajol Jain, Laurent
Vivier, Leonardo Bras, Madhavan Srinivasan, Nathan Chancellor, Nathan
Lynch, Naveen N.  Rao, Nicholas Piggin, Nick Desaulniers, Niklas
Schnelle, Oliver O'Halloran, Rob Herring, Russell Currey, Srikar
Dronamraju, Stan Johnson, Tyrel Datwyler, Uwe Kleine-König, Vasant
Hegde, Wan Jiabing, and Xiaoming Ni,

* tag 'powerpc-5.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (73 commits)
  powerpc/8xx: Fix Oops with STRICT_KERNEL_RWX without DEBUG_RODATA_TEST
  powerpc/32e: Ignore ESR in instruction storage interrupt handler
  powerpc/powernv/prd: Unregister OPAL_MSG_PRD2 notifier during module unload
  powerpc: Don't provide __kernel_map_pages() without ARCH_SUPPORTS_DEBUG_PAGEALLOC
  MAINTAINERS: Update powerpc KVM entry
  powerpc/xmon: fix task state output
  powerpc/44x/fsp2: add missing of_node_put
  powerpc/dcr: Use cmplwi instead of 3-argument cmpli
  KVM: PPC: Tick accounting should defer vtime accounting 'til after IRQ handling
  powerpc/security: Use a mutex for interrupt exit code patching
  powerpc/83xx/mpc8349emitx: Make mcu_gpiochip_remove() return void
  powerpc/fsl_booke: Fix setting of exec flag when setting TLBCAMs
  powerpc/book3e: Fix set_memory_x() and set_memory_nx()
  powerpc/nohash: Fix __ptep_set_access_flags() and ptep_set_wrprotect()
  powerpc/bpf: Fix write protecting JIT code
  selftests/powerpc: Use date instead of EPOCHSECONDS in mitigation-patching.sh
  powerpc/64s/interrupt: Fix check_return_regs_valid() false positive
  powerpc/boot: Set LC_ALL=C in wrapper script
  powerpc/64s: Default to 64K pages for 64 bit book3s
  Revert "powerpc/audit: Convert powerpc to AUDIT_ARCH_COMPAT_GENERIC"
  ...

2 files changed, 151 insertions, 57 deletions

diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c
index cda17bee5afe..c3e06922468b 100644
--- a/arch/powerpc/lib/feature-fixups.c
+++ b/arch/powerpc/lib/feature-fixups.c
@@ -228,6 +228,7 @@ static void do_stf_exit_barrier_fixups(enum stf_barrier_type types)
 
 static bool stf_exit_reentrant = false;
 static bool rfi_exit_reentrant = false;
+static DEFINE_MUTEX(exit_flush_lock);
 
 static int __do_stf_barrier_fixups(void *data)
 {
@@ -253,6 +254,9 @@ void do_stf_barrier_fixups(enum stf_barrier_type types)
 	 * low level interrupt exit code before patching. After the patching,
 	 * if allowed, then flip the branch to allow fast exits.
 	 */
+
+	// Prevent static key update races with do_rfi_flush_fixups()
+	mutex_lock(&exit_flush_lock);
 	static_branch_enable(&interrupt_exit_not_reentrant);
 
 	stop_machine(__do_stf_barrier_fixups, &types, NULL);
@@ -264,6 +268,8 @@ void do_stf_barrier_fixups(enum stf_barrier_type types)
 
 	if (stf_exit_reentrant && rfi_exit_reentrant)
 		static_branch_disable(&interrupt_exit_not_reentrant);
+
+	mutex_unlock(&exit_flush_lock);
 }
 
 void do_uaccess_flush_fixups(enum l1d_flush_type types)
@@ -486,6 +492,9 @@ void do_rfi_flush_fixups(enum l1d_flush_type types)
 	 * without stop_machine, so this could be achieved with a broadcast
 	 * IPI instead, but this matches the stf sequence.
 	 */
+
+	// Prevent static key update races with do_stf_barrier_fixups()
+	mutex_lock(&exit_flush_lock);
 	static_branch_enable(&interrupt_exit_not_reentrant);
 
 	stop_machine(__do_rfi_flush_fixups, &types, NULL);
@@ -497,6 +506,8 @@ void do_rfi_flush_fixups(enum l1d_flush_type types)
 
 	if (stf_exit_reentrant && rfi_exit_reentrant)
 		static_branch_disable(&interrupt_exit_not_reentrant);
+
+	mutex_unlock(&exit_flush_lock);
 }
 
 void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end)
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index d8d5f901cee1..86f49e3e7cf5 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -302,33 +302,51 @@ static nokprobe_inline void do_byte_reverse(void *ptr, int nb)
 	}
 }
 
-static nokprobe_inline int read_mem_aligned(unsigned long *dest,
-					    unsigned long ea, int nb,
-					    struct pt_regs *regs)
+static __always_inline int
+__read_mem_aligned(unsigned long *dest, unsigned long ea, int nb, struct pt_regs *regs)
 {
-	int err = 0;
 	unsigned long x = 0;
 
 	switch (nb) {
 	case 1:
-		err = __get_user(x, (unsigned char __user *) ea);
+		unsafe_get_user(x, (unsigned char __user *)ea, Efault);
 		break;
 	case 2:
-		err = __get_user(x, (unsigned short __user *) ea);
+		unsafe_get_user(x, (unsigned short __user *)ea, Efault);
 		break;
 	case 4:
-		err = __get_user(x, (unsigned int __user *) ea);
+		unsafe_get_user(x, (unsigned int __user *)ea, Efault);
 		break;
 #ifdef __powerpc64__
 	case 8:
-		err = __get_user(x, (unsigned long __user *) ea);
+		unsafe_get_user(x, (unsigned long __user *)ea, Efault);
 		break;
 #endif
 	}
-	if (!err)
-		*dest = x;
-	else
+	*dest = x;
+	return 0;
+
+Efault:
+	regs->dar = ea;
+	return -EFAULT;
+}
+
+static nokprobe_inline int
+read_mem_aligned(unsigned long *dest, unsigned long ea, int nb, struct pt_regs *regs)
+{
+	int err;
+
+	if (is_kernel_addr(ea))
+		return __read_mem_aligned(dest, ea, nb, regs);
+
+	if (user_read_access_begin((void __user *)ea, nb)) {
+		err = __read_mem_aligned(dest, ea, nb, regs);
+		user_read_access_end();
+	} else {
+		err = -EFAULT;
 		regs->dar = ea;
+	}
+
 	return err;
 }
 
@@ -336,10 +354,8 @@ static nokprobe_inline int read_mem_aligned(unsigned long *dest,
  * Copy from userspace to a buffer, using the largest possible
  * aligned accesses, up to sizeof(long).
  */
-static nokprobe_inline int copy_mem_in(u8 *dest, unsigned long ea, int nb,
-				       struct pt_regs *regs)
+static __always_inline int __copy_mem_in(u8 *dest, unsigned long ea, int nb, struct pt_regs *regs)
 {
-	int err = 0;
 	int c;
 
 	for (; nb > 0; nb -= c) {
@@ -348,31 +364,46 @@ static nokprobe_inline int copy_mem_in(u8 *dest, unsigned long ea, int nb,
 			c = max_align(nb);
 		switch (c) {
 		case 1:
-			err = __get_user(*dest, (unsigned char __user *) ea);
+			unsafe_get_user(*dest, (u8 __user *)ea, Efault);
 			break;
 		case 2:
-			err = __get_user(*(u16 *)dest,
-					 (unsigned short __user *) ea);
+			unsafe_get_user(*(u16 *)dest, (u16 __user *)ea, Efault);
 			break;
 		case 4:
-			err = __get_user(*(u32 *)dest,
-					 (unsigned int __user *) ea);
+			unsafe_get_user(*(u32 *)dest, (u32 __user *)ea, Efault);
 			break;
 #ifdef __powerpc64__
 		case 8:
-			err = __get_user(*(unsigned long *)dest,
-					 (unsigned long __user *) ea);
+			unsafe_get_user(*(u64 *)dest, (u64 __user *)ea, Efault);
 			break;
 #endif
 		}
-		if (err) {
-			regs->dar = ea;
-			return err;
-		}
 		dest += c;
 		ea += c;
 	}
 	return 0;
+
+Efault:
+	regs->dar = ea;
+	return -EFAULT;
+}
+
+static nokprobe_inline int copy_mem_in(u8 *dest, unsigned long ea, int nb, struct pt_regs *regs)
+{
+	int err;
+
+	if (is_kernel_addr(ea))
+		return __copy_mem_in(dest, ea, nb, regs);
+
+	if (user_read_access_begin((void __user *)ea, nb)) {
+		err = __copy_mem_in(dest, ea, nb, regs);
+		user_read_access_end();
+	} else {
+		err = -EFAULT;
+		regs->dar = ea;
+	}
+
+	return err;
 }
 
 static nokprobe_inline int read_mem_unaligned(unsigned long *dest,
@@ -410,30 +441,48 @@ static int read_mem(unsigned long *dest, unsigned long ea, int nb,
 }
 NOKPROBE_SYMBOL(read_mem);
 
-static nokprobe_inline int write_mem_aligned(unsigned long val,
-					     unsigned long ea, int nb,
-					     struct pt_regs *regs)
+static __always_inline int
+__write_mem_aligned(unsigned long val, unsigned long ea, int nb, struct pt_regs *regs)
 {
-	int err = 0;
-
 	switch (nb) {
 	case 1:
-		err = __put_user(val, (unsigned char __user *) ea);
+		unsafe_put_user(val, (unsigned char __user *)ea, Efault);
 		break;
 	case 2:
-		err = __put_user(val, (unsigned short __user *) ea);
+		unsafe_put_user(val, (unsigned short __user *)ea, Efault);
 		break;
 	case 4:
-		err = __put_user(val, (unsigned int __user *) ea);
+		unsafe_put_user(val, (unsigned int __user *)ea, Efault);
 		break;
 #ifdef __powerpc64__
 	case 8:
-		err = __put_user(val, (unsigned long __user *) ea);
+		unsafe_put_user(val, (unsigned long __user *)ea, Efault);
 		break;
 #endif
 	}
-	if (err)
+	return 0;
+
+Efault:
+	regs->dar = ea;
+	return -EFAULT;
+}
+
+static nokprobe_inline int
+write_mem_aligned(unsigned long val, unsigned long ea, int nb, struct pt_regs *regs)
+{
+	int err;
+
+	if (is_kernel_addr(ea))
+		return __write_mem_aligned(val, ea, nb, regs);
+
+	if (user_write_access_begin((void __user *)ea, nb)) {
+		err = __write_mem_aligned(val, ea, nb, regs);
+		user_write_access_end();
+	} else {
+		err = -EFAULT;
 		regs->dar = ea;
+	}
+
 	return err;
 }
 
@@ -441,10 +490,8 @@ static nokprobe_inline int write_mem_aligned(unsigned long val,
  * Copy from a buffer to userspace, using the largest possible
  * aligned accesses, up to sizeof(long).
  */
-static nokprobe_inline int copy_mem_out(u8 *dest, unsigned long ea, int nb,
-					struct pt_regs *regs)
+static nokprobe_inline int __copy_mem_out(u8 *dest, unsigned long ea, int nb, struct pt_regs *regs)
 {
-	int err = 0;
 	int c;
 
 	for (; nb > 0; nb -= c) {
@@ -453,31 +500,46 @@ static nokprobe_inline int copy_mem_out(u8 *dest, unsigned long ea, int nb,
 			c = max_align(nb);
 		switch (c) {
 		case 1:
-			err = __put_user(*dest, (unsigned char __user *) ea);
+			unsafe_put_user(*dest, (u8 __user *)ea, Efault);
 			break;
 		case 2:
-			err = __put_user(*(u16 *)dest,
-					 (unsigned short __user *) ea);
+			unsafe_put_user(*(u16 *)dest, (u16 __user *)ea, Efault);
 			break;
 		case 4:
-			err = __put_user(*(u32 *)dest,
-					 (unsigned int __user *) ea);
+			unsafe_put_user(*(u32 *)dest, (u32 __user *)ea, Efault);
 			break;
 #ifdef __powerpc64__
 		case 8:
-			err = __put_user(*(unsigned long *)dest,
-					 (unsigned long __user *) ea);
+			unsafe_put_user(*(u64 *)dest, (u64 __user *)ea, Efault);
 			break;
 #endif
 		}
-		if (err) {
-			regs->dar = ea;
-			return err;
-		}
 		dest += c;
 		ea += c;
 	}
 	return 0;
+
+Efault:
+	regs->dar = ea;
+	return -EFAULT;
+}
+
+static nokprobe_inline int copy_mem_out(u8 *dest, unsigned long ea, int nb, struct pt_regs *regs)
+{
+	int err;
+
+	if (is_kernel_addr(ea))
+		return __copy_mem_out(dest, ea, nb, regs);
+
+	if (user_write_access_begin((void __user *)ea, nb)) {
+		err = __copy_mem_out(dest, ea, nb, regs);
+		user_write_access_end();
+	} else {
+		err = -EFAULT;
+		regs->dar = ea;
+	}
+
+	return err;
 }
 
 static nokprobe_inline int write_mem_unaligned(unsigned long val,
@@ -986,10 +1048,24 @@ static nokprobe_inline int do_vsx_store(struct instruction_op *op,
 }
 #endif /* CONFIG_VSX */
 
+static int __emulate_dcbz(unsigned long ea)
+{
+	unsigned long i;
+	unsigned long size = l1_dcache_bytes();
+
+	for (i = 0; i < size; i += sizeof(long))
+		unsafe_put_user(0, (unsigned long __user *)(ea + i), Efault);
+
+	return 0;
+
+Efault:
+	return -EFAULT;
+}
+
 int emulate_dcbz(unsigned long ea, struct pt_regs *regs)
 {
 	int err;
-	unsigned long i, size;
+	unsigned long size;
 
 #ifdef __powerpc64__
 	size = ppc64_caches.l1d.block_size;
@@ -1001,14 +1077,21 @@ int emulate_dcbz(unsigned long ea, struct pt_regs *regs)
 	ea &= ~(size - 1);
 	if (!address_ok(regs, ea, size))
 		return -EFAULT;
-	for (i = 0; i < size; i += sizeof(long)) {
-		err = __put_user(0, (unsigned long __user *) (ea + i));
-		if (err) {
-			regs->dar = ea;
-			return err;
-		}
+
+	if (is_kernel_addr(ea)) {
+		err = __emulate_dcbz(ea);
+	} else if (user_write_access_begin((void __user *)ea, size)) {
+		err = __emulate_dcbz(ea);
+		user_write_access_end();
+	} else {
+		err = -EFAULT;
 	}
-	return 0;
+
+	if (err)
+		regs->dar = ea;
+
+
+	return err;
 }
 NOKPROBE_SYMBOL(emulate_dcbz);