@@ -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
@@ -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));
@@ -43,34 +47,73 @@ 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;
}
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);
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> --- arch/parisc/include/asm/patch.h | 4 +- arch/parisc/kernel/patch.c | 75 ++++++++++++++++++++++++++------- 2 files changed, 62 insertions(+), 17 deletions(-)