diff options
Diffstat (limited to 'arch/x86/kernel/alternative.c')
| -rw-r--r-- | arch/x86/kernel/alternative.c | 39 |
1 files changed, 19 insertions, 20 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index df4099dc1c6..65c7857a90d 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -511,31 +511,30 @@ void *__kprobes text_poke(void *addr, const void *opcode, size_t len) unsigned long flags; char *vaddr; int nr_pages = 2; + struct page *pages[2]; + int i; - BUG_ON(len > sizeof(long)); - BUG_ON((((long)addr + len - 1) & ~(sizeof(long) - 1)) - - ((long)addr & ~(sizeof(long) - 1))); - if (kernel_text_address((unsigned long)addr)) { - struct page *pages[2] = { virt_to_page(addr), - virt_to_page(addr + PAGE_SIZE) }; - if (!pages[1]) - nr_pages = 1; - vaddr = vmap(pages, nr_pages, VM_MAP, PAGE_KERNEL); - BUG_ON(!vaddr); - local_irq_save(flags); - memcpy(&vaddr[(unsigned long)addr & ~PAGE_MASK], opcode, len); - local_irq_restore(flags); - vunmap(vaddr); + if (!core_kernel_text((unsigned long)addr)) { + pages[0] = vmalloc_to_page(addr); + pages[1] = vmalloc_to_page(addr + PAGE_SIZE); } else { - /* - * modules are in vmalloc'ed memory, always writable. - */ - local_irq_save(flags); - memcpy(addr, opcode, len); - local_irq_restore(flags); + pages[0] = virt_to_page(addr); + WARN_ON(!PageReserved(pages[0])); + pages[1] = virt_to_page(addr + PAGE_SIZE); } + BUG_ON(!pages[0]); + if (!pages[1]) + nr_pages = 1; + vaddr = vmap(pages, nr_pages, VM_MAP, PAGE_KERNEL); + BUG_ON(!vaddr); + local_irq_save(flags); + memcpy(&vaddr[(unsigned long)addr & ~PAGE_MASK], opcode, len); + local_irq_restore(flags); + vunmap(vaddr); sync_core(); /* Could also do a CLFLUSH here to speed up CPU recovery; but that causes hangs on some VIA CPUs. */ + for (i = 0; i < len; i++) + BUG_ON(((char *)addr)[i] != ((char *)opcode)[i]); return addr; } |