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authorSven Schnelle <svens@stackframe.org>2019-06-05 22:32:18 +0200
committerHelge Deller <deller@gmx.de>2019-06-08 12:56:26 +0200
commit7e923369b1ec92af5f048d2146b44f9132abe1ad (patch)
treee1ebdd4596415f23e2b008c9e5e6642b4b6995e1 /arch/parisc
parent4e87ace902cf0d401376cac89bb6a5239e57fe9f (diff)
downloadlinux-7e923369b1ec92af5f048d2146b44f9132abe1ad.tar.bz2
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>
Diffstat (limited to 'arch/parisc')
-rw-r--r--arch/parisc/kernel/patch.c25
1 files changed, 19 insertions, 6 deletions
diff --git a/arch/parisc/kernel/patch.c b/arch/parisc/kernel/patch.c
index 70e9997a3f80..80a0ab372802 100644
--- 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);
}