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authorAlexei Starovoitov <ast@plumgrid.com>2014-09-16 18:32:58 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-10-30 09:40:19 -0700
commit6e2d91c6331f33a7bbec6285b5eaad379cabe31e (patch)
tree6a296d4768040575221338f0aa006f36fb060fc7
parenta068a292f5c1fb7ca0a914342c7403406827a856 (diff)
downloadlinux-linaro-stable-6e2d91c6331f33a7bbec6285b5eaad379cabe31e.tar.gz
sparc: bpf_jit: fix support for ldx/stx mem and SKF_AD_VLAN_TAG
[ Upstream commit f6f2332dce0efeea8c5653b6e9d1e8c379ace65c ] fix several issues in sparc BPF JIT compiler. ldx/stx related: . classic BPF instructions that access mem[] slots were not setting SEEN_MEM flag, so stack wasn't allocated. Fix that by advertising correct flags . LDX/STX instructions were missing SEEN_XREG, so register value could have leaked to user space. Fix it. . since stack for mem[] slots is allocated with 'sub %sp' instead of 'save %sp', use %sp as base register instead of %fp. . ldx mem[0] means first slot in classic BPF which should have -4 offset instead of 0. . sparc64 needs 2047 stack bias as per ABI to access stack . emit_stmem() was using LD32I macro instead of ST32I SKF_AD_VLAN_TAG* related: . SKF_AD_VLAN_TAG_PRESENT must return 1 or 0 instead of '> 0' or 0 as per classic BPF de facto standard . SKF_AD_VLAN_TAG needs to mask the field correctly Fixes: 2809a2087cc4 ("net: filter: Just In Time compiler for sparc") Signed-off-by: Alexei Starovoitov <ast@plumgrid.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--arch/sparc/net/bpf_jit_comp.c25
1 files changed, 18 insertions, 7 deletions
diff --git a/arch/sparc/net/bpf_jit_comp.c b/arch/sparc/net/bpf_jit_comp.c
index 892a102671ad..69d6181a058d 100644
--- a/arch/sparc/net/bpf_jit_comp.c
+++ b/arch/sparc/net/bpf_jit_comp.c
@@ -234,12 +234,18 @@ do { BUILD_BUG_ON(FIELD_SIZEOF(STRUCT, FIELD) != sizeof(u8)); \
__emit_load8(BASE, STRUCT, FIELD, DEST); \
} while (0)
-#define emit_ldmem(OFF, DEST) \
-do { *prog++ = LD32I | RS1(FP) | S13(-(OFF)) | RD(DEST); \
+#ifdef CONFIG_SPARC64
+#define BIAS (STACK_BIAS - 4)
+#else
+#define BIAS (-4)
+#endif
+
+#define emit_ldmem(OFF, DEST) \
+do { *prog++ = LD32I | RS1(SP) | S13(BIAS - (OFF)) | RD(DEST); \
} while (0)
-#define emit_stmem(OFF, SRC) \
-do { *prog++ = LD32I | RS1(FP) | S13(-(OFF)) | RD(SRC); \
+#define emit_stmem(OFF, SRC) \
+do { *prog++ = ST32I | RS1(SP) | S13(BIAS - (OFF)) | RD(SRC); \
} while (0)
#ifdef CONFIG_SMP
@@ -615,10 +621,11 @@ void bpf_jit_compile(struct sk_filter *fp)
case BPF_ANC | SKF_AD_VLAN_TAG:
case BPF_ANC | SKF_AD_VLAN_TAG_PRESENT:
emit_skb_load16(vlan_tci, r_A);
- if (code == (BPF_ANC | SKF_AD_VLAN_TAG)) {
- emit_andi(r_A, VLAN_VID_MASK, r_A);
+ if (code != (BPF_ANC | SKF_AD_VLAN_TAG)) {
+ emit_alu_K(SRL, 12);
+ emit_andi(r_A, 1, r_A);
} else {
- emit_loadimm(VLAN_TAG_PRESENT, r_TMP);
+ emit_loadimm(~VLAN_TAG_PRESENT, r_TMP);
emit_and(r_A, r_TMP, r_A);
}
break;
@@ -630,15 +637,19 @@ void bpf_jit_compile(struct sk_filter *fp)
emit_loadimm(K, r_X);
break;
case BPF_LD | BPF_MEM:
+ seen |= SEEN_MEM;
emit_ldmem(K * 4, r_A);
break;
case BPF_LDX | BPF_MEM:
+ seen |= SEEN_MEM | SEEN_XREG;
emit_ldmem(K * 4, r_X);
break;
case BPF_ST:
+ seen |= SEEN_MEM;
emit_stmem(K * 4, r_A);
break;
case BPF_STX:
+ seen |= SEEN_MEM | SEEN_XREG;
emit_stmem(K * 4, r_X);
break;