parisc: add support for patching multiple words

add patch_text_multiple() which allows to patch multiple
text words in memory. This can be used to copy functions.

Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/arch/parisc/include/asm/patch.h b/arch/parisc/include/asm/patch.h
index 685b58a..400d84c 100644 (file)
--- a/arch/parisc/include/asm/patch.h
+++ b/arch/parisc/include/asm/patch.h
@@ -4,8 +4,10 @@
 
 /* stop machine and patch kernel text */
 void patch_text(void *addr, unsigned int insn);
+void patch_text_multiple(void *addr, u32 *insn, unsigned int len);
 
 /* patch kernel text with machine already stopped (e.g. in kgdb) */
-void __patch_text(void *addr, unsigned int insn);
+void __patch_text(void *addr, u32 insn);
+void __patch_text_multiple(void *addr, u32 *insn, unsigned int len);
 
 #endif

diff --git a/arch/parisc/kernel/patch.c b/arch/parisc/kernel/patch.c
index cdcd981..70e9997 100644 (file)
--- a/arch/parisc/kernel/patch.c
+++ b/arch/parisc/kernel/patch.c
@@ -17,15 +17,18 @@
 
 struct patch {
        void *addr;
-       unsigned int insn;
+       u32 *insn;
+       unsigned int len;
 };
 
-static void __kprobes *patch_map(void *addr, int fixmap)
-{
+static DEFINE_RAW_SPINLOCK(patch_lock);
+
+static void __kprobes *patch_map(void *addr, int fixmap, int *need_unmap)
        unsigned long uintaddr = (uintptr_t) addr;
        bool module = !core_kernel_text(uintaddr);
        struct page *page;
 
+       *need_unmap = 0;
        if (module && IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
                page = vmalloc_to_page(addr);
        else if (!module && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
@@ -33,6 +36,7 @@ static void __kprobes *patch_map(void *addr, int fixmap)
        else
                return addr;
 
+       *need_unmap = 1;
        set_fixmap(fixmap, page_to_phys(page));
 
        return (void *) (__fix_to_virt(fixmap) + (uintaddr & ~PAGE_MASK));
@@ -43,26 +47,52 @@ static void __kprobes patch_unmap(int fixmap)
        clear_fixmap(fixmap);
 }
 
-void __kprobes __patch_text(void *addr, unsigned int insn)
+void __kprobes __patch_text_multiple(void *addr, u32 *insn, unsigned int len)
+{
+       unsigned long start = (unsigned long)addr;
+       unsigned long end = (unsigned long)addr + len;
+       u32 *p, *fixmap;
+       int mapped;
+
+       /* Make sure we don't have any aliases in cache */
+       flush_kernel_vmap_range(addr, len);
+       flush_icache_range(start, end);
+
+       p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &mapped);
+
+       while (len >= 4) {
+               *p++ = *insn++;
+               addr += sizeof(u32);
+               len -= sizeof(u32);
+               if (len && offset_in_page(addr) == 0) {
+                       /*
+                        * We're crossing a page boundary, so
+                        * need to remap
+                        */
+                       flush_kernel_vmap_range((void *)fixmap,
+                                               (p-fixmap) * sizeof(*p));
+                       if (mapped)
+                               patch_unmap(FIX_TEXT_POKE0);
+                       p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &mapped);
+               }
+       }
+
+       flush_kernel_vmap_range((void *)fixmap, (p-fixmap) * sizeof(*p));
+       if (mapped)
+               patch_unmap(FIX_TEXT_POKE0);
+       flush_icache_range(start, end);
+}
+
+void __kprobes __patch_text(void *addr, u32 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);
+       __patch_text_multiple(addr, &insn, sizeof(insn));
 }
 
 static int __kprobes patch_text_stop_machine(void *data)
 {
        struct patch *patch = data;
 
-       __patch_text(patch->addr, patch->insn);
-
+       __patch_text_multiple(patch->addr, patch->insn, patch->len);
        return 0;
 }
 
@@ -70,7 +100,20 @@ void __kprobes patch_text(void *addr, unsigned int insn)
 {
        struct patch patch = {
                .addr = addr,
+               .insn = &insn,
+               .len = sizeof(insn),
+       };
+
+       stop_machine_cpuslocked(patch_text_stop_machine, &patch, NULL);
+}
+
+void __kprobes patch_text_multiple(void *addr, u32 *insn, unsigned int len)
+{
+
+       struct patch patch = {
+               .addr = addr,
                .insn = insn,
+               .len = len
        };
 
        stop_machine_cpuslocked(patch_text_stop_machine, &patch, NULL);