diff options
Diffstat (limited to 'arch/arm64/kernel/insn.c')
| -rw-r--r-- | arch/arm64/kernel/insn.c | 49 |
1 files changed, 48 insertions, 1 deletions
diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c index 7e9327a0986d..c8eca88f12e6 100644 --- a/arch/arm64/kernel/insn.c +++ b/arch/arm64/kernel/insn.c @@ -17,14 +17,19 @@ * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <linux/bitops.h> +#include <linux/bug.h> #include <linux/compiler.h> #include <linux/kernel.h> +#include <linux/mm.h> #include <linux/smp.h> +#include <linux/spinlock.h> #include <linux/stop_machine.h> +#include <linux/types.h> #include <linux/uaccess.h> #include <asm/cacheflush.h> #include <asm/debug-monitors.h> +#include <asm/fixmap.h> #include <asm/insn.h> #define AARCH64_INSN_SF_BIT BIT(31) @@ -72,6 +77,31 @@ bool __kprobes aarch64_insn_is_nop(u32 insn) } } +static DEFINE_SPINLOCK(patch_lock); + +static void __kprobes *patch_map(void *addr, int fixmap) +{ + unsigned long uintaddr = (uintptr_t) addr; + bool module = !core_kernel_text(uintaddr); + struct page *page; + + if (module && IS_ENABLED(CONFIG_DEBUG_SET_MODULE_RONX)) + page = vmalloc_to_page(addr); + else if (!module && IS_ENABLED(CONFIG_DEBUG_RODATA)) + page = virt_to_page(addr); + else + return addr; + + BUG_ON(!page); + set_fixmap(fixmap, page_to_phys(page)); + + return (void *) (__fix_to_virt(fixmap) + (uintaddr & ~PAGE_MASK)); +} + +static void __kprobes patch_unmap(int fixmap) +{ + clear_fixmap(fixmap); +} /* * In ARMv8-A, A64 instructions have a fixed length of 32 bits and are always * little-endian. @@ -88,10 +118,27 @@ int __kprobes aarch64_insn_read(void *addr, u32 *insnp) return ret; } +static int __kprobes __aarch64_insn_write(void *addr, u32 insn) +{ + void *waddr = addr; + unsigned long flags = 0; + int ret; + + spin_lock_irqsave(&patch_lock, flags); + waddr = patch_map(addr, FIX_TEXT_POKE0); + + ret = probe_kernel_write(waddr, &insn, AARCH64_INSN_SIZE); + + patch_unmap(FIX_TEXT_POKE0); + spin_unlock_irqrestore(&patch_lock, flags); + + return ret; +} + int __kprobes aarch64_insn_write(void *addr, u32 insn) { insn = cpu_to_le32(insn); - return probe_kernel_write(addr, &insn, AARCH64_INSN_SIZE); + return __aarch64_insn_write(addr, insn); } static bool __kprobes __aarch64_insn_hotpatch_safe(u32 insn) |