Merge tag 'powerpc-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:

 - Support for userspace to send requests directly to the on-chip GZIP
   accelerator on Power9.

 - Rework of our lockless page table walking (__find_linux_pte()) to
   make it safe against parallel page table manipulations without
   relying on an IPI for serialisation.

 - A series of fixes & enhancements to make our machine check handling
   more robust.

 - Lots of plumbing to add support for "prefixed" (64-bit) instructions
   on Power10.

 - Support for using huge pages for the linear mapping on 8xx (32-bit).

 - Remove obsolete Xilinx PPC405/PPC440 support, and an associated sound
   driver.

 - Removal of some obsolete 40x platforms and associated cruft.

 - Initial support for booting on Power10.

 - Lots of other small features, cleanups & fixes.

Thanks to: Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan,
Andrey Abramov, Aneesh Kumar K.V, Balamuruhan S, Bharata B Rao, Bulent
Abali, Cédric Le Goater, Chen Zhou, Christian Zigotzky, Christophe
JAILLET, Christophe Leroy, Dmitry Torokhov, Emmanuel Nicolet, Erhard F.,
Gautham R. Shenoy, Geoff Levand, George Spelvin, Greg Kurz, Gustavo A.
R. Silva, Gustavo Walbon, Haren Myneni, Hari Bathini, Joel Stanley,
Jordan Niethe, Kajol Jain, Kees Cook, Leonardo Bras, Madhavan
Srinivasan., Mahesh Salgaonkar, Markus Elfring, Michael Neuling, Michal
Simek, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin,
Oliver O'Halloran, Paul Mackerras, Pingfan Liu, Qian Cai, Ram Pai,
Raphael Moreira Zinsly, Ravi Bangoria, Sam Bobroff, Sandipan Das, Segher
Boessenkool, Stephen Rothwell, Sukadev Bhattiprolu, Tyrel Datwyler,
Wolfram Sang, Xiongfeng Wang.

* tag 'powerpc-5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (299 commits)
  powerpc/pseries: Make vio and ibmebus initcalls pseries specific
  cxl: Remove dead Kconfig options
  powerpc: Add POWER10 architected mode
  powerpc/dt_cpu_ftrs: Add MMA feature
  powerpc/dt_cpu_ftrs: Enable Prefixed Instructions
  powerpc/dt_cpu_ftrs: Advertise support for ISA v3.1 if selected
  powerpc: Add support for ISA v3.1
  powerpc: Add new HWCAP bits
  powerpc/64s: Don't set FSCR bits in INIT_THREAD
  powerpc/64s: Save FSCR to init_task.thread.fscr after feature init
  powerpc/64s: Don't let DT CPU features set FSCR_DSCR
  powerpc/64s: Don't init FSCR_DSCR in __init_FSCR()
  powerpc/32s: Fix another build failure with CONFIG_PPC_KUAP_DEBUG
  powerpc/module_64: Use special stub for _mcount() with -mprofile-kernel
  powerpc/module_64: Simplify check for -mprofile-kernel ftrace relocations
  powerpc/module_64: Consolidate ftrace code
  powerpc/32: Disable KASAN with pages bigger than 16k
  powerpc/uaccess: Don't set KUEP by default on book3s/32
  powerpc/uaccess: Don't set KUAP by default on book3s/32
  powerpc/8xx: Reduce time spent in allow_user_access() and friends
  ...

1 files changed, 32 insertions, 15 deletions

diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 81efb605113e..6f96f65ebfe8 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -23,6 +23,7 @@
 #include <asm/cacheflush.h>
 #include <asm/sstep.h>
 #include <asm/sections.h>
+#include <asm/inst.h>
 #include <linux/uaccess.h>
 
 DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
@@ -105,7 +106,9 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset)
 int arch_prepare_kprobe(struct kprobe *p)
 {
 	int ret = 0;
-	kprobe_opcode_t insn = *p->addr;
+	struct kprobe *prev;
+	struct ppc_inst insn = ppc_inst_read((struct ppc_inst *)p->addr);
+	struct ppc_inst prefix = ppc_inst_read((struct ppc_inst *)(p->addr - 1));
 
 	if ((unsigned long)p->addr & 0x03) {
 		printk("Attempt to register kprobe at an unaligned address\n");
@@ -113,6 +116,17 @@ int arch_prepare_kprobe(struct kprobe *p)
 	} else if (IS_MTMSRD(insn) || IS_RFID(insn) || IS_RFI(insn)) {
 		printk("Cannot register a kprobe on rfi/rfid or mtmsr[d]\n");
 		ret = -EINVAL;
+	} else if (ppc_inst_prefixed(prefix)) {
+		printk("Cannot register a kprobe on the second word of prefixed instruction\n");
+		ret = -EINVAL;
+	}
+	preempt_disable();
+	prev = get_kprobe(p->addr - 1);
+	preempt_enable_no_resched();
+	if (prev &&
+	    ppc_inst_prefixed(ppc_inst_read((struct ppc_inst *)prev->ainsn.insn))) {
+		printk("Cannot register a kprobe on the second word of prefixed instruction\n");
+		ret = -EINVAL;
 	}
 
 	/* insn must be on a special executable page on ppc64.  This is
@@ -124,11 +138,8 @@ int arch_prepare_kprobe(struct kprobe *p)
 	}
 
 	if (!ret) {
-		memcpy(p->ainsn.insn, p->addr,
-				MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
-		p->opcode = *p->addr;
-		flush_icache_range((unsigned long)p->ainsn.insn,
-			(unsigned long)p->ainsn.insn + sizeof(kprobe_opcode_t));
+		patch_instruction((struct ppc_inst *)p->ainsn.insn, insn);
+		p->opcode = ppc_inst_val(insn);
 	}
 
 	p->ainsn.boostable = 0;
@@ -138,13 +149,13 @@ NOKPROBE_SYMBOL(arch_prepare_kprobe);
 
 void arch_arm_kprobe(struct kprobe *p)
 {
-	patch_instruction(p->addr, BREAKPOINT_INSTRUCTION);
+	patch_instruction((struct ppc_inst *)p->addr, ppc_inst(BREAKPOINT_INSTRUCTION));
 }
 NOKPROBE_SYMBOL(arch_arm_kprobe);
 
 void arch_disarm_kprobe(struct kprobe *p)
 {
-	patch_instruction(p->addr, p->opcode);
+	patch_instruction((struct ppc_inst *)p->addr, ppc_inst(p->opcode));
 }
 NOKPROBE_SYMBOL(arch_disarm_kprobe);
 
@@ -216,7 +227,7 @@ NOKPROBE_SYMBOL(arch_prepare_kretprobe);
 static int try_to_emulate(struct kprobe *p, struct pt_regs *regs)
 {
 	int ret;
-	unsigned int insn = *p->ainsn.insn;
+	struct ppc_inst insn = ppc_inst_read((struct ppc_inst *)p->ainsn.insn);
 
 	/* regs->nip is also adjusted if emulate_step returns 1 */
 	ret = emulate_step(regs, insn);
@@ -233,7 +244,7 @@ static int try_to_emulate(struct kprobe *p, struct pt_regs *regs)
 		 * So, we should never get here... but, its still
 		 * good to catch them, just in case...
 		 */
-		printk("Can't step on instruction %x\n", insn);
+		printk("Can't step on instruction %x\n", ppc_inst_val(insn));
 		BUG();
 	} else {
 		/*
@@ -276,14 +287,18 @@ int kprobe_handler(struct pt_regs *regs)
 
 	p = get_kprobe(addr);
 	if (!p) {
-		if (*addr != BREAKPOINT_INSTRUCTION) {
+		unsigned int instr;
+
+		if (probe_kernel_address(addr, instr))
+			goto no_kprobe;
+
+		if (instr != BREAKPOINT_INSTRUCTION) {
 			/*
 			 * PowerPC has multiple variants of the "trap"
 			 * instruction. If the current instruction is a
 			 * trap variant, it could belong to someone else
 			 */
-			kprobe_opcode_t cur_insn = *addr;
-			if (is_trap(cur_insn))
+			if (is_trap(instr))
 				goto no_kprobe;
 			/*
 			 * The breakpoint instruction was removed right
@@ -464,14 +479,16 @@ NOKPROBE_SYMBOL(trampoline_probe_handler);
  */
 int kprobe_post_handler(struct pt_regs *regs)
 {
+	int len;
 	struct kprobe *cur = kprobe_running();
 	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
 
 	if (!cur || user_mode(regs))
 		return 0;
 
+	len = ppc_inst_len(ppc_inst_read((struct ppc_inst *)cur->ainsn.insn));
 	/* make sure we got here for instruction we have a kprobe on */
-	if (((unsigned long)cur->ainsn.insn + 4) != regs->nip)
+	if (((unsigned long)cur->ainsn.insn + len) != regs->nip)
 		return 0;
 
 	if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
@@ -480,7 +497,7 @@ int kprobe_post_handler(struct pt_regs *regs)
 	}
 
 	/* Adjust nip to after the single-stepped instruction */
-	regs->nip = (unsigned long)cur->addr + 4;
+	regs->nip = (unsigned long)cur->addr + len;
 	regs->msr |= kcb->kprobe_saved_msr;
 
 	/*Restore back the original saved kprobes variables and continue. */