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Diffstat (limited to 'arch/s390/net/bpf_jit_comp.c')
-rw-r--r--arch/s390/net/bpf_jit_comp.c93
1 files changed, 51 insertions, 42 deletions
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index fee782acc2ee..eeda051442c3 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -45,7 +45,7 @@ struct bpf_jit {
int labels[1]; /* Labels for local jumps */
};
-#define BPF_SIZE_MAX 4096 /* Max size for program */
+#define BPF_SIZE_MAX 0x7ffff /* Max size for program (20 bit signed displ) */
#define SEEN_SKB 1 /* skb access */
#define SEEN_MEM 2 /* use mem[] for temporary storage */
@@ -53,6 +53,7 @@ struct bpf_jit {
#define SEEN_LITERAL 8 /* code uses literals */
#define SEEN_FUNC 16 /* calls C functions */
#define SEEN_TAIL_CALL 32 /* code uses tail calls */
+#define SEEN_SKB_CHANGE 64 /* code changes skb data */
#define SEEN_STACK (SEEN_FUNC | SEEN_MEM | SEEN_SKB)
/*
@@ -203,19 +204,11 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
_EMIT6(op1 | __disp, op2); \
})
-#define EMIT6_DISP(op1, op2, b1, b2, b3, disp) \
-({ \
- _EMIT6_DISP(op1 | reg(b1, b2) << 16 | \
- reg_high(b3) << 8, op2, disp); \
- REG_SET_SEEN(b1); \
- REG_SET_SEEN(b2); \
- REG_SET_SEEN(b3); \
-})
-
#define _EMIT6_DISP_LH(op1, op2, disp) \
({ \
- unsigned int __disp_h = ((u32)disp) & 0xff000; \
- unsigned int __disp_l = ((u32)disp) & 0x00fff; \
+ u32 _disp = (u32) disp; \
+ unsigned int __disp_h = _disp & 0xff000; \
+ unsigned int __disp_l = _disp & 0x00fff; \
_EMIT6(op1 | __disp_l, op2 | __disp_h >> 4); \
})
@@ -390,12 +383,32 @@ static void save_restore_regs(struct bpf_jit *jit, int op)
}
/*
+ * For SKB access %b1 contains the SKB pointer. For "bpf_jit.S"
+ * we store the SKB header length on the stack and the SKB data
+ * pointer in REG_SKB_DATA.
+ */
+static void emit_load_skb_data_hlen(struct bpf_jit *jit)
+{
+ /* Header length: llgf %w1,<len>(%b1) */
+ EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_1,
+ offsetof(struct sk_buff, len));
+ /* s %w1,<data_len>(%b1) */
+ EMIT4_DISP(0x5b000000, REG_W1, BPF_REG_1,
+ offsetof(struct sk_buff, data_len));
+ /* stg %w1,ST_OFF_HLEN(%r0,%r15) */
+ EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0, REG_15, STK_OFF_HLEN);
+ /* lg %skb_data,data_off(%b1) */
+ EMIT6_DISP_LH(0xe3000000, 0x0004, REG_SKB_DATA, REG_0,
+ BPF_REG_1, offsetof(struct sk_buff, data));
+}
+
+/*
* Emit function prologue
*
* Save registers and create stack frame if necessary.
* See stack frame layout desription in "bpf_jit.h"!
*/
-static void bpf_jit_prologue(struct bpf_jit *jit)
+static void bpf_jit_prologue(struct bpf_jit *jit, bool is_classic)
{
if (jit->seen & SEEN_TAIL_CALL) {
/* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */
@@ -429,32 +442,21 @@ static void bpf_jit_prologue(struct bpf_jit *jit)
EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0,
REG_15, 152);
}
- /*
- * For SKB access %b1 contains the SKB pointer. For "bpf_jit.S"
- * we store the SKB header length on the stack and the SKB data
- * pointer in REG_SKB_DATA.
- */
- if (jit->seen & SEEN_SKB) {
- /* Header length: llgf %w1,<len>(%b1) */
- EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_1,
- offsetof(struct sk_buff, len));
- /* s %w1,<data_len>(%b1) */
- EMIT4_DISP(0x5b000000, REG_W1, BPF_REG_1,
- offsetof(struct sk_buff, data_len));
- /* stg %w1,ST_OFF_HLEN(%r0,%r15) */
+ if (jit->seen & SEEN_SKB)
+ emit_load_skb_data_hlen(jit);
+ if (jit->seen & SEEN_SKB_CHANGE)
+ /* stg %b1,ST_OFF_SKBP(%r0,%r15) */
EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0, REG_15,
- STK_OFF_HLEN);
- /* lg %skb_data,data_off(%b1) */
- EMIT6_DISP_LH(0xe3000000, 0x0004, REG_SKB_DATA, REG_0,
- BPF_REG_1, offsetof(struct sk_buff, data));
+ STK_OFF_SKBP);
+ /* Clear A (%b0) and X (%b7) registers for converted BPF programs */
+ if (is_classic) {
+ if (REG_SEEN(BPF_REG_A))
+ /* lghi %ba,0 */
+ EMIT4_IMM(0xa7090000, BPF_REG_A, 0);
+ if (REG_SEEN(BPF_REG_X))
+ /* lghi %bx,0 */
+ EMIT4_IMM(0xa7090000, BPF_REG_X, 0);
}
- /* BPF compatibility: clear A (%b7) and X (%b8) registers */
- if (REG_SEEN(BPF_REG_7))
- /* lghi %b7,0 */
- EMIT4_IMM(0xa7090000, BPF_REG_7, 0);
- if (REG_SEEN(BPF_REG_8))
- /* lghi %b8,0 */
- EMIT4_IMM(0xa7090000, BPF_REG_8, 0);
}
/*
@@ -976,12 +978,19 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
REG_SET_SEEN(BPF_REG_5);
jit->seen |= SEEN_FUNC;
/* lg %w1,<d(imm)>(%l) */
- EMIT6_DISP(0xe3000000, 0x0004, REG_W1, REG_0, REG_L,
- EMIT_CONST_U64(func));
+ EMIT6_DISP_LH(0xe3000000, 0x0004, REG_W1, REG_0, REG_L,
+ EMIT_CONST_U64(func));
/* basr %r14,%w1 */
EMIT2(0x0d00, REG_14, REG_W1);
/* lgr %b0,%r2: load return value into %b0 */
EMIT4(0xb9040000, BPF_REG_0, REG_2);
+ if (bpf_helper_changes_skb_data((void *)func)) {
+ jit->seen |= SEEN_SKB_CHANGE;
+ /* lg %b1,ST_OFF_SKBP(%r15) */
+ EMIT6_DISP_LH(0xe3000000, 0x0004, BPF_REG_1, REG_0,
+ REG_15, STK_OFF_SKBP);
+ emit_load_skb_data_hlen(jit);
+ }
break;
}
case BPF_JMP | BPF_CALL | BPF_X:
@@ -1023,7 +1032,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
MAX_TAIL_CALL_CNT, 0, 0x2);
/*
- * prog = array->prog[index];
+ * prog = array->ptrs[index];
* if (prog == NULL)
* goto out;
*/
@@ -1032,7 +1041,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
EMIT6_DISP_LH(0xeb000000, 0x000d, REG_1, BPF_REG_3, REG_0, 3);
/* lg %r1,prog(%b2,%r1) */
EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, BPF_REG_2,
- REG_1, offsetof(struct bpf_array, prog));
+ REG_1, offsetof(struct bpf_array, ptrs));
/* clgij %r1,0,0x8,label0 */
EMIT6_PCREL_IMM_LABEL(0xec000000, 0x007d, REG_1, 0, 0, 0x8);
@@ -1236,7 +1245,7 @@ static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp)
jit->lit = jit->lit_start;
jit->prg = 0;
- bpf_jit_prologue(jit);
+ bpf_jit_prologue(jit, bpf_prog_was_classic(fp));
for (i = 0; i < fp->len; i += insn_count) {
insn_count = bpf_jit_insn(jit, fp, i);
if (insn_count < 0)
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