diff options
| -rw-r--r-- | arch/arm/net/bpf_jit_32.c | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c index a76623b..2d1a5b9 100644 --- a/arch/arm/net/bpf_jit_32.c +++ b/arch/arm/net/bpf_jit_32.c @@ -12,7 +12,6 @@ #include <linux/compiler.h> #include <linux/errno.h> #include <linux/filter.h> -#include <linux/moduleloader.h> #include <linux/netdevice.h> #include <linux/string.h> #include <linux/slab.h> @@ -174,6 +173,15 @@ static inline bool is_load_to_a(u16 inst) } } +static void jit_fill_hole(void *area, unsigned int size) +{ + /* Insert illegal UND instructions. */ + u32 *ptr, fill_ins = 0xe7ffffff; + /* We are guaranteed to have aligned memory. */ + for (ptr = area; size >= sizeof(u32); size -= sizeof(u32)) + *ptr++ = fill_ins; +} + static void build_prologue(struct jit_ctx *ctx) { u16 reg_set = saved_regs(ctx); @@ -859,9 +867,11 @@ b_epilogue: void bpf_jit_compile(struct bpf_prog *fp) { + struct bpf_binary_header *header; struct jit_ctx ctx; unsigned tmp_idx; unsigned alloc_size; + u8 *target_ptr; if (!bpf_jit_enable) return; @@ -897,13 +907,15 @@ void bpf_jit_compile(struct bpf_prog *fp) /* there's nothing after the epilogue on ARMv7 */ build_epilogue(&ctx); #endif - alloc_size = 4 * ctx.idx; - ctx.target = module_alloc(alloc_size); - if (unlikely(ctx.target == NULL)) + header = bpf_jit_binary_alloc(alloc_size, &target_ptr, + 4, jit_fill_hole); + if (header == NULL) goto out; + ctx.target = (u32 *) target_ptr; ctx.idx = 0; + build_prologue(&ctx); build_body(&ctx); build_epilogue(&ctx); @@ -919,6 +931,7 @@ void bpf_jit_compile(struct bpf_prog *fp) /* there are 2 passes here */ bpf_jit_dump(fp->len, alloc_size, 2, ctx.target); + set_memory_ro((unsigned long)header, header->pages); fp->bpf_func = (void *)ctx.target; fp->jited = 1; out: @@ -928,8 +941,15 @@ out: void bpf_jit_free(struct bpf_prog *fp) { - if (fp->jited) - module_free(NULL, fp->bpf_func); + unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK; + struct bpf_binary_header *header = (void *)addr; + + if (!fp->jited) + goto free_filter; + + set_memory_rw(addr, header->pages); + bpf_jit_binary_free(header); +free_filter: bpf_prog_unlock_free(fp); } |
