parisc: add spinlock to patch function

If multiple CPUs are patching code we need the spinlock
to protect against parallel fixmap maps/unmap calls.

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

diff --git a/arch/parisc/kernel/patch.c b/arch/parisc/kernel/patch.c
index 70e9997a3f803b6c0cc9056dd8253167ec15ee49..80a0ab372802db148a1ccb0867bc0eb8ae3b7b69 100644 (file)
--- a/arch/parisc/kernel/patch.c
+++ b/arch/parisc/kernel/patch.c
@@ -23,7 +23,9 @@ struct patch {
 
 static DEFINE_RAW_SPINLOCK(patch_lock);
 
-static void __kprobes *patch_map(void *addr, int fixmap, int *need_unmap)
+static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags,
+                                int *need_unmap)
+{
        unsigned long uintaddr = (uintptr_t) addr;
        bool module = !core_kernel_text(uintaddr);
        struct page *page;
@@ -38,19 +40,29 @@ static void __kprobes *patch_map(void *addr, int fixmap, int *need_unmap)
 
        *need_unmap = 1;
        set_fixmap(fixmap, page_to_phys(page));
+       if (flags)
+               raw_spin_lock_irqsave(&patch_lock, *flags);
+       else
+               __acquire(&patch_lock);
 
        return (void *) (__fix_to_virt(fixmap) + (uintaddr & ~PAGE_MASK));
 }
 
-static void __kprobes patch_unmap(int fixmap)
+static void __kprobes patch_unmap(int fixmap, unsigned long *flags)
 {
        clear_fixmap(fixmap);
+
+       if (flags)
+               raw_spin_unlock_irqrestore(&patch_lock, *flags);
+       else
+               __release(&patch_lock);
 }
 
 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;
+       unsigned long flags;
        u32 *p, *fixmap;
        int mapped;
 
@@ -58,7 +70,7 @@ void __kprobes __patch_text_multiple(void *addr, u32 *insn, unsigned int len)
        flush_kernel_vmap_range(addr, len);
        flush_icache_range(start, end);
 
-       p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &mapped);
+       p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &flags, &mapped);
 
        while (len >= 4) {
                *p++ = *insn++;
@@ -72,14 +84,15 @@ void __kprobes __patch_text_multiple(void *addr, u32 *insn, unsigned int len)
                        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);
+                               patch_unmap(FIX_TEXT_POKE0, &flags);
+                       p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &flags,
+                                               &mapped);
                }
        }
 
        flush_kernel_vmap_range((void *)fixmap, (p-fixmap) * sizeof(*p));
        if (mapped)
-               patch_unmap(FIX_TEXT_POKE0);
+               patch_unmap(FIX_TEXT_POKE0, &flags);
        flush_icache_range(start, end);
 }