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-rw-r--r--arch/arm/net/bpf_jit_32.c32
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 a76623bcf722..2d1a5b93d91c 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -12,7 +12,6 @@
12#include <linux/compiler.h> 12#include <linux/compiler.h>
13#include <linux/errno.h> 13#include <linux/errno.h>
14#include <linux/filter.h> 14#include <linux/filter.h>
15#include <linux/moduleloader.h>
16#include <linux/netdevice.h> 15#include <linux/netdevice.h>
17#include <linux/string.h> 16#include <linux/string.h>
18#include <linux/slab.h> 17#include <linux/slab.h>
@@ -174,6 +173,15 @@ static inline bool is_load_to_a(u16 inst)
174 } 173 }
175} 174}
176 175
176static void jit_fill_hole(void *area, unsigned int size)
177{
178 /* Insert illegal UND instructions. */
179 u32 *ptr, fill_ins = 0xe7ffffff;
180 /* We are guaranteed to have aligned memory. */
181 for (ptr = area; size >= sizeof(u32); size -= sizeof(u32))
182 *ptr++ = fill_ins;
183}
184
177static void build_prologue(struct jit_ctx *ctx) 185static void build_prologue(struct jit_ctx *ctx)
178{ 186{
179 u16 reg_set = saved_regs(ctx); 187 u16 reg_set = saved_regs(ctx);
@@ -859,9 +867,11 @@ b_epilogue:
859 867
860void bpf_jit_compile(struct bpf_prog *fp) 868void bpf_jit_compile(struct bpf_prog *fp)
861{ 869{
870 struct bpf_binary_header *header;
862 struct jit_ctx ctx; 871 struct jit_ctx ctx;
863 unsigned tmp_idx; 872 unsigned tmp_idx;
864 unsigned alloc_size; 873 unsigned alloc_size;
874 u8 *target_ptr;
865 875
866 if (!bpf_jit_enable) 876 if (!bpf_jit_enable)
867 return; 877 return;
@@ -897,13 +907,15 @@ void bpf_jit_compile(struct bpf_prog *fp)
897 /* there's nothing after the epilogue on ARMv7 */ 907 /* there's nothing after the epilogue on ARMv7 */
898 build_epilogue(&ctx); 908 build_epilogue(&ctx);
899#endif 909#endif
900
901 alloc_size = 4 * ctx.idx; 910 alloc_size = 4 * ctx.idx;
902 ctx.target = module_alloc(alloc_size); 911 header = bpf_jit_binary_alloc(alloc_size, &target_ptr,
903 if (unlikely(ctx.target == NULL)) 912 4, jit_fill_hole);
913 if (header == NULL)
904 goto out; 914 goto out;
905 915
916 ctx.target = (u32 *) target_ptr;
906 ctx.idx = 0; 917 ctx.idx = 0;
918
907 build_prologue(&ctx); 919 build_prologue(&ctx);
908 build_body(&ctx); 920 build_body(&ctx);
909 build_epilogue(&ctx); 921 build_epilogue(&ctx);
@@ -919,6 +931,7 @@ void bpf_jit_compile(struct bpf_prog *fp)
919 /* there are 2 passes here */ 931 /* there are 2 passes here */
920 bpf_jit_dump(fp->len, alloc_size, 2, ctx.target); 932 bpf_jit_dump(fp->len, alloc_size, 2, ctx.target);
921 933
934 set_memory_ro((unsigned long)header, header->pages);
922 fp->bpf_func = (void *)ctx.target; 935 fp->bpf_func = (void *)ctx.target;
923 fp->jited = 1; 936 fp->jited = 1;
924out: 937out:
@@ -928,8 +941,15 @@ out:
928 941
929void bpf_jit_free(struct bpf_prog *fp) 942void bpf_jit_free(struct bpf_prog *fp)
930{ 943{
931 if (fp->jited) 944 unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK;
932 module_free(NULL, fp->bpf_func); 945 struct bpf_binary_header *header = (void *)addr;
946
947 if (!fp->jited)
948 goto free_filter;
949
950 set_memory_rw(addr, header->pages);
951 bpf_jit_binary_free(header);
933 952
953free_filter:
934 bpf_prog_unlock_free(fp); 954 bpf_prog_unlock_free(fp);
935} 955}