diff options
| author | Alexei Starovoitov <ast@plumgrid.com> | 2014-09-16 18:32:58 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-10-30 09:40:19 -0700 |
| commit | 6e2d91c6331f33a7bbec6285b5eaad379cabe31e (patch) | |
| tree | 6a296d4768040575221338f0aa006f36fb060fc7 | |
| parent | a068a292f5c1fb7ca0a914342c7403406827a856 (diff) | |
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.c | 25 |
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 892a102671a..69d6181a058 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; |