Merge branch 'parisc-5.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux

Pull parisc updates from Helge Deller:
 "Many great new features, fixes and optimizations, including:

   - Convert page table updates to use per-pagetable spinlocks which
     overall improves performance on SMP machines a lot, by Mikulas
     Patocka

   - Kernel debugger (KGDB) support, by Sven Schnelle

   - KPROBES support, by Sven Schnelle

   - Lots of TLB lock/flush improvements, by Dave Anglin

   - Drop DISCONTIGMEM and switch to SPARSEMEM

   - Added JUMP_LABEL, branch runtime-patching support

   - Lots of other small speedups and cleanups, e.g. for QEMU, stack
     randomization, avoidance of name clashes, documentation updates,
     etc ..."

* 'parisc-5.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: (28 commits)
  parisc: Add static branch and JUMP_LABEL feature
  parisc: Use PA_ASM_LEVEL in boot code
  parisc: Rename LEVEL to PA_ASM_LEVEL to avoid name clash with DRBD code
  parisc: Update huge TLB page support to use per-pagetable spinlock
  parisc: Use per-pagetable spinlock
  parisc: Allow live-patching of __meminit functions
  parisc: Add memory barrier to asm pdc and sync instructions
  parisc: Add memory clobber to TLB purges
  parisc: Use ldcw instruction for SMP spinlock release barrier
  parisc: Remove lock code to serialize TLB operations in pacache.S
  parisc: Switch from DISCONTIGMEM to SPARSEMEM
  parisc: enable wide mode early
  parisc: update feature lists
  parisc: Show n/a if product number not available
  parisc: remove unused flags parameter in __patch_text()
  doc: update kprobes supported architecture list
  parisc: Implement kretprobes
  parisc: remove kprobes.h from generic-y
  parisc: Implement kprobes
  parisc: add functions required by KPROBE_EVENTS
  ...

1 files changed, 77 insertions, 0 deletions

diff --git a/arch/parisc/kernel/patch.c b/arch/parisc/kernel/patch.c
new file mode 100644
index 000000000000..cdcd981278b3
--- /dev/null
+++ b/arch/parisc/kernel/patch.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+ /*
+  * functions to patch RO kernel text during runtime
+  *
+  * Copyright (c) 2019 Sven Schnelle <svens@stackframe.org>
+  */
+
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/kprobes.h>
+#include <linux/mm.h>
+#include <linux/stop_machine.h>
+
+#include <asm/cacheflush.h>
+#include <asm/fixmap.h>
+#include <asm/patch.h>
+
+struct patch {
+	void *addr;
+	unsigned int insn;
+};
+
+static void __kprobes *patch_map(void *addr, int fixmap)
+{
+	unsigned long uintaddr = (uintptr_t) addr;
+	bool module = !core_kernel_text(uintaddr);
+	struct page *page;
+
+	if (module && IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
+		page = vmalloc_to_page(addr);
+	else if (!module && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
+		page = virt_to_page(addr);
+	else
+		return addr;
+
+	set_fixmap(fixmap, page_to_phys(page));
+
+	return (void *) (__fix_to_virt(fixmap) + (uintaddr & ~PAGE_MASK));
+}
+
+static void __kprobes patch_unmap(int fixmap)
+{
+	clear_fixmap(fixmap);
+}
+
+void __kprobes __patch_text(void *addr, unsigned int insn)
+{
+	void *waddr = addr;
+	int size;
+
+	waddr = patch_map(addr, FIX_TEXT_POKE0);
+	*(u32 *)waddr = insn;
+	size = sizeof(u32);
+	flush_kernel_vmap_range(waddr, size);
+	patch_unmap(FIX_TEXT_POKE0);
+	flush_icache_range((uintptr_t)(addr),
+			   (uintptr_t)(addr) + size);
+}
+
+static int __kprobes patch_text_stop_machine(void *data)
+{
+	struct patch *patch = data;
+
+	__patch_text(patch->addr, patch->insn);
+
+	return 0;
+}
+
+void __kprobes patch_text(void *addr, unsigned int insn)
+{
+	struct patch patch = {
+		.addr = addr,
+		.insn = insn,
+	};
+
+	stop_machine_cpuslocked(patch_text_stop_machine, &patch, NULL);
+}