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authorLinus Torvalds <torvalds@linux-foundation.org>2021-09-21 09:36:11 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-21 09:36:11 -0700
commit92477dd1faa650e50bd3bb35a6c0b8d09198cc35 (patch)
treeb7abe1ba33f12aed22c3e2b1eda58bb98ccfa2e2 /arch/s390
parentd5f6545934c47e97c0b48a645418e877b452a992 (diff)
parentdb7bee653859ef7179be933e7d1384644f795f26 (diff)
Merge tag 's390-5.15-ebpf-jit-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 eBPF fixes from Vasily Gorbik: "Johan Almbladh has implemented a number of new testcases for eBPF [1], which uncovered three miscompilation issues in the s390 eBPF JIT" Link: https://lore.kernel.org/bpf/20210902185229.1840281-1-johan.almbladh@anyfinetworks.com/ [1] * tag 's390-5.15-ebpf-jit-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/bpf: Fix optimizing out zero-extensions s390/bpf: Fix 64-bit subtraction of the -0x80000000 constant s390/bpf: Fix branch shortening during codegen pass
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/net/bpf_jit_comp.c70
1 files changed, 38 insertions, 32 deletions
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index 88419263a89a..840d8594437d 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -248,8 +248,7 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
#define EMIT6_PCREL(op1, op2, b1, b2, i, off, mask) \
({ \
- /* Branch instruction needs 6 bytes */ \
- int rel = (addrs[(i) + (off) + 1] - (addrs[(i) + 1] - 6)) / 2;\
+ int rel = (addrs[(i) + (off) + 1] - jit->prg) / 2; \
_EMIT6((op1) | reg(b1, b2) << 16 | (rel & 0xffff), (op2) | (mask));\
REG_SET_SEEN(b1); \
REG_SET_SEEN(b2); \
@@ -761,10 +760,10 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT4(0xb9080000, dst_reg, src_reg);
break;
case BPF_ALU | BPF_ADD | BPF_K: /* dst = (u32) dst + (u32) imm */
- if (!imm)
- break;
- /* alfi %dst,imm */
- EMIT6_IMM(0xc20b0000, dst_reg, imm);
+ if (imm != 0) {
+ /* alfi %dst,imm */
+ EMIT6_IMM(0xc20b0000, dst_reg, imm);
+ }
EMIT_ZERO(dst_reg);
break;
case BPF_ALU64 | BPF_ADD | BPF_K: /* dst = dst + imm */
@@ -786,17 +785,22 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT4(0xb9090000, dst_reg, src_reg);
break;
case BPF_ALU | BPF_SUB | BPF_K: /* dst = (u32) dst - (u32) imm */
- if (!imm)
- break;
- /* alfi %dst,-imm */
- EMIT6_IMM(0xc20b0000, dst_reg, -imm);
+ if (imm != 0) {
+ /* alfi %dst,-imm */
+ EMIT6_IMM(0xc20b0000, dst_reg, -imm);
+ }
EMIT_ZERO(dst_reg);
break;
case BPF_ALU64 | BPF_SUB | BPF_K: /* dst = dst - imm */
if (!imm)
break;
- /* agfi %dst,-imm */
- EMIT6_IMM(0xc2080000, dst_reg, -imm);
+ if (imm == -0x80000000) {
+ /* algfi %dst,0x80000000 */
+ EMIT6_IMM(0xc20a0000, dst_reg, 0x80000000);
+ } else {
+ /* agfi %dst,-imm */
+ EMIT6_IMM(0xc2080000, dst_reg, -imm);
+ }
break;
/*
* BPF_MUL
@@ -811,10 +815,10 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT4(0xb90c0000, dst_reg, src_reg);
break;
case BPF_ALU | BPF_MUL | BPF_K: /* dst = (u32) dst * (u32) imm */
- if (imm == 1)
- break;
- /* msfi %r5,imm */
- EMIT6_IMM(0xc2010000, dst_reg, imm);
+ if (imm != 1) {
+ /* msfi %r5,imm */
+ EMIT6_IMM(0xc2010000, dst_reg, imm);
+ }
EMIT_ZERO(dst_reg);
break;
case BPF_ALU64 | BPF_MUL | BPF_K: /* dst = dst * imm */
@@ -867,6 +871,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
if (BPF_OP(insn->code) == BPF_MOD)
/* lhgi %dst,0 */
EMIT4_IMM(0xa7090000, dst_reg, 0);
+ else
+ EMIT_ZERO(dst_reg);
break;
}
/* lhi %w0,0 */
@@ -999,10 +1005,10 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT4(0xb9820000, dst_reg, src_reg);
break;
case BPF_ALU | BPF_XOR | BPF_K: /* dst = (u32) dst ^ (u32) imm */
- if (!imm)
- break;
- /* xilf %dst,imm */
- EMIT6_IMM(0xc0070000, dst_reg, imm);
+ if (imm != 0) {
+ /* xilf %dst,imm */
+ EMIT6_IMM(0xc0070000, dst_reg, imm);
+ }
EMIT_ZERO(dst_reg);
break;
case BPF_ALU64 | BPF_XOR | BPF_K: /* dst = dst ^ imm */
@@ -1033,10 +1039,10 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, src_reg, 0);
break;
case BPF_ALU | BPF_LSH | BPF_K: /* dst = (u32) dst << (u32) imm */
- if (imm == 0)
- break;
- /* sll %dst,imm(%r0) */
- EMIT4_DISP(0x89000000, dst_reg, REG_0, imm);
+ if (imm != 0) {
+ /* sll %dst,imm(%r0) */
+ EMIT4_DISP(0x89000000, dst_reg, REG_0, imm);
+ }
EMIT_ZERO(dst_reg);
break;
case BPF_ALU64 | BPF_LSH | BPF_K: /* dst = dst << imm */
@@ -1058,10 +1064,10 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, src_reg, 0);
break;
case BPF_ALU | BPF_RSH | BPF_K: /* dst = (u32) dst >> (u32) imm */
- if (imm == 0)
- break;
- /* srl %dst,imm(%r0) */
- EMIT4_DISP(0x88000000, dst_reg, REG_0, imm);
+ if (imm != 0) {
+ /* srl %dst,imm(%r0) */
+ EMIT4_DISP(0x88000000, dst_reg, REG_0, imm);
+ }
EMIT_ZERO(dst_reg);
break;
case BPF_ALU64 | BPF_RSH | BPF_K: /* dst = dst >> imm */
@@ -1083,10 +1089,10 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, src_reg, 0);
break;
case BPF_ALU | BPF_ARSH | BPF_K: /* ((s32) dst >> imm */
- if (imm == 0)
- break;
- /* sra %dst,imm(%r0) */
- EMIT4_DISP(0x8a000000, dst_reg, REG_0, imm);
+ if (imm != 0) {
+ /* sra %dst,imm(%r0) */
+ EMIT4_DISP(0x8a000000, dst_reg, REG_0, imm);
+ }
EMIT_ZERO(dst_reg);
break;
case BPF_ALU64 | BPF_ARSH | BPF_K: /* ((s64) dst) >>= imm */