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Diffstat (limited to 'arch/s390/net/bpf_jit_comp.c')
-rw-r--r--arch/s390/net/bpf_jit_comp.c502
1 files changed, 369 insertions, 133 deletions
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index ce88211b9c6c..8d2134136290 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -23,6 +23,8 @@
#include <linux/filter.h>
#include <linux/init.h>
#include <linux/bpf.h>
+#include <linux/mm.h>
+#include <linux/kernel.h>
#include <asm/cacheflush.h>
#include <asm/dis.h>
#include <asm/facility.h>
@@ -38,10 +40,11 @@ struct bpf_jit {
int size; /* Size of program and literal pool */
int size_prg; /* Size of program */
int prg; /* Current position in program */
- int lit_start; /* Start of literal pool */
- int lit; /* Current position in literal pool */
+ int lit32_start; /* Start of 32-bit literal pool */
+ int lit32; /* Current position in 32-bit literal pool */
+ int lit64_start; /* Start of 64-bit literal pool */
+ int lit64; /* Current position in 64-bit literal pool */
int base_ip; /* Base address for literal pool */
- int ret0_ip; /* Address of return 0 */
int exit_ip; /* Address of exit */
int r1_thunk_ip; /* Address of expoline thunk for 'br %r1' */
int r14_thunk_ip; /* Address of expoline thunk for 'br %r14' */
@@ -49,14 +52,10 @@ struct bpf_jit {
int labels[1]; /* Labels for local jumps */
};
-#define BPF_SIZE_MAX 0xffff /* Max size for program (16 bit branches) */
-
-#define SEEN_MEM (1 << 0) /* use mem[] for temporary storage */
-#define SEEN_RET0 (1 << 1) /* ret0_ip points to a valid return 0 */
-#define SEEN_LITERAL (1 << 2) /* code uses literals */
-#define SEEN_FUNC (1 << 3) /* calls C functions */
-#define SEEN_TAIL_CALL (1 << 4) /* code uses tail calls */
-#define SEEN_REG_AX (1 << 5) /* code uses constant blinding */
+#define SEEN_MEM BIT(0) /* use mem[] for temporary storage */
+#define SEEN_LITERAL BIT(1) /* code uses literals */
+#define SEEN_FUNC BIT(2) /* calls C functions */
+#define SEEN_TAIL_CALL BIT(3) /* code uses tail calls */
#define SEEN_STACK (SEEN_FUNC | SEEN_MEM)
/*
@@ -131,13 +130,13 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
#define _EMIT2(op) \
({ \
if (jit->prg_buf) \
- *(u16 *) (jit->prg_buf + jit->prg) = op; \
+ *(u16 *) (jit->prg_buf + jit->prg) = (op); \
jit->prg += 2; \
})
#define EMIT2(op, b1, b2) \
({ \
- _EMIT2(op | reg(b1, b2)); \
+ _EMIT2((op) | reg(b1, b2)); \
REG_SET_SEEN(b1); \
REG_SET_SEEN(b2); \
})
@@ -145,20 +144,20 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
#define _EMIT4(op) \
({ \
if (jit->prg_buf) \
- *(u32 *) (jit->prg_buf + jit->prg) = op; \
+ *(u32 *) (jit->prg_buf + jit->prg) = (op); \
jit->prg += 4; \
})
#define EMIT4(op, b1, b2) \
({ \
- _EMIT4(op | reg(b1, b2)); \
+ _EMIT4((op) | reg(b1, b2)); \
REG_SET_SEEN(b1); \
REG_SET_SEEN(b2); \
})
#define EMIT4_RRF(op, b1, b2, b3) \
({ \
- _EMIT4(op | reg_high(b3) << 8 | reg(b1, b2)); \
+ _EMIT4((op) | reg_high(b3) << 8 | reg(b1, b2)); \
REG_SET_SEEN(b1); \
REG_SET_SEEN(b2); \
REG_SET_SEEN(b3); \
@@ -167,13 +166,13 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
#define _EMIT4_DISP(op, disp) \
({ \
unsigned int __disp = (disp) & 0xfff; \
- _EMIT4(op | __disp); \
+ _EMIT4((op) | __disp); \
})
#define EMIT4_DISP(op, b1, b2, disp) \
({ \
- _EMIT4_DISP(op | reg_high(b1) << 16 | \
- reg_high(b2) << 8, disp); \
+ _EMIT4_DISP((op) | reg_high(b1) << 16 | \
+ reg_high(b2) << 8, (disp)); \
REG_SET_SEEN(b1); \
REG_SET_SEEN(b2); \
})
@@ -181,21 +180,27 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
#define EMIT4_IMM(op, b1, imm) \
({ \
unsigned int __imm = (imm) & 0xffff; \
- _EMIT4(op | reg_high(b1) << 16 | __imm); \
+ _EMIT4((op) | reg_high(b1) << 16 | __imm); \
REG_SET_SEEN(b1); \
})
#define EMIT4_PCREL(op, pcrel) \
({ \
long __pcrel = ((pcrel) >> 1) & 0xffff; \
- _EMIT4(op | __pcrel); \
+ _EMIT4((op) | __pcrel); \
+})
+
+#define EMIT4_PCREL_RIC(op, mask, target) \
+({ \
+ int __rel = ((target) - jit->prg) / 2; \
+ _EMIT4((op) | (mask) << 20 | (__rel & 0xffff)); \
})
#define _EMIT6(op1, op2) \
({ \
if (jit->prg_buf) { \
- *(u32 *) (jit->prg_buf + jit->prg) = op1; \
- *(u16 *) (jit->prg_buf + jit->prg + 4) = op2; \
+ *(u32 *) (jit->prg_buf + jit->prg) = (op1); \
+ *(u16 *) (jit->prg_buf + jit->prg + 4) = (op2); \
} \
jit->prg += 6; \
})
@@ -203,20 +208,20 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
#define _EMIT6_DISP(op1, op2, disp) \
({ \
unsigned int __disp = (disp) & 0xfff; \
- _EMIT6(op1 | __disp, op2); \
+ _EMIT6((op1) | __disp, op2); \
})
#define _EMIT6_DISP_LH(op1, op2, disp) \
({ \
- u32 _disp = (u32) disp; \
+ u32 _disp = (u32) (disp); \
unsigned int __disp_h = _disp & 0xff000; \
unsigned int __disp_l = _disp & 0x00fff; \
- _EMIT6(op1 | __disp_l, op2 | __disp_h >> 4); \
+ _EMIT6((op1) | __disp_l, (op2) | __disp_h >> 4); \
})
#define EMIT6_DISP_LH(op1, op2, b1, b2, b3, disp) \
({ \
- _EMIT6_DISP_LH(op1 | reg(b1, b2) << 16 | \
+ _EMIT6_DISP_LH((op1) | reg(b1, b2) << 16 | \
reg_high(b3) << 8, op2, disp); \
REG_SET_SEEN(b1); \
REG_SET_SEEN(b2); \
@@ -226,8 +231,8 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
#define EMIT6_PCREL_LABEL(op1, op2, b1, b2, label, mask) \
({ \
int rel = (jit->labels[label] - jit->prg) >> 1; \
- _EMIT6(op1 | reg(b1, b2) << 16 | (rel & 0xffff), \
- op2 | mask << 12); \
+ _EMIT6((op1) | reg(b1, b2) << 16 | (rel & 0xffff), \
+ (op2) | (mask) << 12); \
REG_SET_SEEN(b1); \
REG_SET_SEEN(b2); \
})
@@ -235,68 +240,83 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
#define EMIT6_PCREL_IMM_LABEL(op1, op2, b1, imm, label, mask) \
({ \
int rel = (jit->labels[label] - jit->prg) >> 1; \
- _EMIT6(op1 | (reg_high(b1) | mask) << 16 | \
- (rel & 0xffff), op2 | (imm & 0xff) << 8); \
+ _EMIT6((op1) | (reg_high(b1) | (mask)) << 16 | \
+ (rel & 0xffff), (op2) | ((imm) & 0xff) << 8); \
REG_SET_SEEN(b1); \
- BUILD_BUG_ON(((unsigned long) imm) > 0xff); \
+ BUILD_BUG_ON(((unsigned long) (imm)) > 0xff); \
})
#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;\
- _EMIT6(op1 | reg(b1, b2) << 16 | (rel & 0xffff), op2 | mask); \
+ int rel = (addrs[(i) + (off) + 1] - (addrs[(i) + 1] - 6)) / 2;\
+ _EMIT6((op1) | reg(b1, b2) << 16 | (rel & 0xffff), (op2) | (mask));\
REG_SET_SEEN(b1); \
REG_SET_SEEN(b2); \
})
#define EMIT6_PCREL_RILB(op, b, target) \
({ \
- int rel = (target - jit->prg) / 2; \
- _EMIT6(op | reg_high(b) << 16 | rel >> 16, rel & 0xffff); \
+ unsigned int rel = (int)((target) - jit->prg) / 2; \
+ _EMIT6((op) | reg_high(b) << 16 | rel >> 16, rel & 0xffff);\
REG_SET_SEEN(b); \
})
#define EMIT6_PCREL_RIL(op, target) \
({ \
- int rel = (target - jit->prg) / 2; \
- _EMIT6(op | rel >> 16, rel & 0xffff); \
+ unsigned int rel = (int)((target) - jit->prg) / 2; \
+ _EMIT6((op) | rel >> 16, rel & 0xffff); \
+})
+
+#define EMIT6_PCREL_RILC(op, mask, target) \
+({ \
+ EMIT6_PCREL_RIL((op) | (mask) << 20, (target)); \
})
#define _EMIT6_IMM(op, imm) \
({ \
unsigned int __imm = (imm); \
- _EMIT6(op | (__imm >> 16), __imm & 0xffff); \
+ _EMIT6((op) | (__imm >> 16), __imm & 0xffff); \
})
#define EMIT6_IMM(op, b1, imm) \
({ \
- _EMIT6_IMM(op | reg_high(b1) << 16, imm); \
+ _EMIT6_IMM((op) | reg_high(b1) << 16, imm); \
REG_SET_SEEN(b1); \
})
-#define EMIT_CONST_U32(val) \
+#define _EMIT_CONST_U32(val) \
({ \
unsigned int ret; \
- ret = jit->lit - jit->base_ip; \
- jit->seen |= SEEN_LITERAL; \
+ ret = jit->lit32; \
if (jit->prg_buf) \
- *(u32 *) (jit->prg_buf + jit->lit) = (u32) val; \
- jit->lit += 4; \
+ *(u32 *)(jit->prg_buf + jit->lit32) = (u32)(val);\
+ jit->lit32 += 4; \
ret; \
})
-#define EMIT_CONST_U64(val) \
+#define EMIT_CONST_U32(val) \
({ \
- unsigned int ret; \
- ret = jit->lit - jit->base_ip; \
jit->seen |= SEEN_LITERAL; \
+ _EMIT_CONST_U32(val) - jit->base_ip; \
+})
+
+#define _EMIT_CONST_U64(val) \
+({ \
+ unsigned int ret; \
+ ret = jit->lit64; \
if (jit->prg_buf) \
- *(u64 *) (jit->prg_buf + jit->lit) = (u64) val; \
- jit->lit += 8; \
+ *(u64 *)(jit->prg_buf + jit->lit64) = (u64)(val);\
+ jit->lit64 += 8; \
ret; \
})
+#define EMIT_CONST_U64(val) \
+({ \
+ jit->seen |= SEEN_LITERAL; \
+ _EMIT_CONST_U64(val) - jit->base_ip; \
+})
+
#define EMIT_ZERO(b1) \
({ \
if (!fp->aux->verifier_zext) { \
@@ -307,6 +327,67 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
})
/*
+ * Return whether this is the first pass. The first pass is special, since we
+ * don't know any sizes yet, and thus must be conservative.
+ */
+static bool is_first_pass(struct bpf_jit *jit)
+{
+ return jit->size == 0;
+}
+
+/*
+ * Return whether this is the code generation pass. The code generation pass is
+ * special, since we should change as little as possible.
+ */
+static bool is_codegen_pass(struct bpf_jit *jit)
+{
+ return jit->prg_buf;
+}
+
+/*
+ * Return whether "rel" can be encoded as a short PC-relative offset
+ */
+static bool is_valid_rel(int rel)
+{
+ return rel >= -65536 && rel <= 65534;
+}
+
+/*
+ * Return whether "off" can be reached using a short PC-relative offset
+ */
+static bool can_use_rel(struct bpf_jit *jit, int off)
+{
+ return is_valid_rel(off - jit->prg);
+}
+
+/*
+ * Return whether given displacement can be encoded using
+ * Long-Displacement Facility
+ */
+static bool is_valid_ldisp(int disp)
+{
+ return disp >= -524288 && disp <= 524287;
+}
+
+/*
+ * Return whether the next 32-bit literal pool entry can be referenced using
+ * Long-Displacement Facility
+ */
+static bool can_use_ldisp_for_lit32(struct bpf_jit *jit)
+{
+ return is_valid_ldisp(jit->lit32 - jit->base_ip);
+}
+
+/*
+ * Return whether the next 64-bit literal pool entry can be referenced using
+ * Long-Displacement Facility
+ */
+static bool can_use_ldisp_for_lit64(struct bpf_jit *jit)
+{
+ return is_valid_ldisp(jit->lit64 - jit->base_ip);
+}
+
+/*
* Fill whole space with illegal instructions
*/
static void jit_fill_hole(void *area, unsigned int size)
@@ -383,9 +464,18 @@ static int get_end(struct bpf_jit *jit, int start)
*/
static void save_restore_regs(struct bpf_jit *jit, int op, u32 stack_depth)
{
-
+ const int last = 15, save_restore_size = 6;
int re = 6, rs;
+ if (is_first_pass(jit)) {
+ /*
+ * We don't know yet which registers are used. Reserve space
+ * conservatively.
+ */
+ jit->prg += (last - re + 1) * save_restore_size;
+ return;
+ }
+
do {
rs = get_start(jit, re);
if (!rs)
@@ -396,7 +486,7 @@ static void save_restore_regs(struct bpf_jit *jit, int op, u32 stack_depth)
else
restore_regs(jit, rs, re, stack_depth);
re++;
- } while (re <= 15);
+ } while (re <= last);
}
/*
@@ -420,21 +510,28 @@ static void bpf_jit_prologue(struct bpf_jit *jit, u32 stack_depth)
/* Save registers */
save_restore_regs(jit, REGS_SAVE, stack_depth);
/* Setup literal pool */
- if (jit->seen & SEEN_LITERAL) {
- /* basr %r13,0 */
- EMIT2(0x0d00, REG_L, REG_0);
- jit->base_ip = jit->prg;
+ if (is_first_pass(jit) || (jit->seen & SEEN_LITERAL)) {
+ if (!is_first_pass(jit) &&
+ is_valid_ldisp(jit->size - (jit->prg + 2))) {
+ /* basr %l,0 */
+ EMIT2(0x0d00, REG_L, REG_0);
+ jit->base_ip = jit->prg;
+ } else {
+ /* larl %l,lit32_start */
+ EMIT6_PCREL_RILB(0xc0000000, REG_L, jit->lit32_start);
+ jit->base_ip = jit->lit32_start;
+ }
}
/* Setup stack and backchain */
- if (jit->seen & SEEN_STACK) {
- if (jit->seen & SEEN_FUNC)
+ if (is_first_pass(jit) || (jit->seen & SEEN_STACK)) {
+ if (is_first_pass(jit) || (jit->seen & SEEN_FUNC))
/* lgr %w1,%r15 (backchain) */
EMIT4(0xb9040000, REG_W1, REG_15);
/* la %bfp,STK_160_UNUSED(%r15) (BPF frame pointer) */
EMIT4_DISP(0x41000000, BPF_REG_FP, REG_15, STK_160_UNUSED);
/* aghi %r15,-STK_OFF */
EMIT4_IMM(0xa70b0000, REG_15, -(STK_OFF + stack_depth));
- if (jit->seen & SEEN_FUNC)
+ if (is_first_pass(jit) || (jit->seen & SEEN_FUNC))
/* stg %w1,152(%r15) (backchain) */
EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W1, REG_0,
REG_15, 152);
@@ -446,12 +543,6 @@ static void bpf_jit_prologue(struct bpf_jit *jit, u32 stack_depth)
*/
static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth)
{
- /* Return 0 */
- if (jit->seen & SEEN_RET0) {
- jit->ret0_ip = jit->prg;
- /* lghi %b0,0 */
- EMIT4_IMM(0xa7090000, BPF_REG_0, 0);
- }
jit->exit_ip = jit->prg;
/* Load exit code: lgr %r2,%b0 */
EMIT4(0xb9040000, REG_2, BPF_REG_0);
@@ -476,7 +567,7 @@ static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth)
_EMIT2(0x07fe);
if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable &&
- (jit->seen & SEEN_FUNC)) {
+ (is_first_pass(jit) || (jit->seen & SEEN_FUNC))) {
jit->r1_thunk_ip = jit->prg;
/* Generate __s390_indirect_jump_r1 thunk */
if (test_facility(35)) {
@@ -506,16 +597,14 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
int i, bool extra_pass)
{
struct bpf_insn *insn = &fp->insnsi[i];
- int jmp_off, last, insn_count = 1;
u32 dst_reg = insn->dst_reg;
u32 src_reg = insn->src_reg;
+ int last, insn_count = 1;
u32 *addrs = jit->addrs;
s32 imm = insn->imm;
s16 off = insn->off;
unsigned int mask;
- if (dst_reg == BPF_REG_AX || src_reg == BPF_REG_AX)
- jit->seen |= SEEN_REG_AX;
switch (insn->code) {
/*
* BPF_MOV
@@ -549,9 +638,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
u64 imm64;
imm64 = (u64)(u32) insn[0].imm | ((u64)(u32) insn[1].imm) << 32;
- /* lg %dst,<d(imm)>(%l) */
- EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, REG_0, REG_L,
- EMIT_CONST_U64(imm64));
+ /* lgrl %dst,imm */
+ EMIT6_PCREL_RILB(0xc4080000, dst_reg, _EMIT_CONST_U64(imm64));
insn_count = 2;
break;
}
@@ -680,9 +768,18 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT4_IMM(0xa7080000, REG_W0, 0);
/* lr %w1,%dst */
EMIT2(0x1800, REG_W1, dst_reg);
- /* dl %w0,<d(imm)>(%l) */
- EMIT6_DISP_LH(0xe3000000, 0x0097, REG_W0, REG_0, REG_L,
- EMIT_CONST_U32(imm));
+ if (!is_first_pass(jit) && can_use_ldisp_for_lit32(jit)) {
+ /* dl %w0,<d(imm)>(%l) */
+ EMIT6_DISP_LH(0xe3000000, 0x0097, REG_W0, REG_0, REG_L,
+ EMIT_CONST_U32(imm));
+ } else {
+ /* lgfrl %dst,imm */
+ EMIT6_PCREL_RILB(0xc40c0000, dst_reg,
+ _EMIT_CONST_U32(imm));
+ jit->seen |= SEEN_LITERAL;
+ /* dlr %w0,%dst */
+ EMIT4(0xb9970000, REG_W0, dst_reg);
+ }
/* llgfr %dst,%rc */
EMIT4(0xb9160000, dst_reg, rc_reg);
if (insn_is_zext(&insn[1]))
@@ -704,9 +801,18 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT4_IMM(0xa7090000, REG_W0, 0);
/* lgr %w1,%dst */
EMIT4(0xb9040000, REG_W1, dst_reg);
- /* dlg %w0,<d(imm)>(%l) */
- EMIT6_DISP_LH(0xe3000000, 0x0087, REG_W0, REG_0, REG_L,
- EMIT_CONST_U64(imm));
+ if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
+ /* dlg %w0,<d(imm)>(%l) */
+ EMIT6_DISP_LH(0xe3000000, 0x0087, REG_W0, REG_0, REG_L,
+ EMIT_CONST_U64(imm));
+ } else {
+ /* lgrl %dst,imm */
+ EMIT6_PCREL_RILB(0xc4080000, dst_reg,
+ _EMIT_CONST_U64(imm));
+ jit->seen |= SEEN_LITERAL;
+ /* dlgr %w0,%dst */
+ EMIT4(0xb9870000, REG_W0, dst_reg);
+ }
/* lgr %dst,%rc */
EMIT4(0xb9040000, dst_reg, rc_reg);
break;
@@ -729,9 +835,19 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT_ZERO(dst_reg);
break;
case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
- /* ng %dst,<d(imm)>(%l) */
- EMIT6_DISP_LH(0xe3000000, 0x0080, dst_reg, REG_0, REG_L,
- EMIT_CONST_U64(imm));
+ if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
+ /* ng %dst,<d(imm)>(%l) */
+ EMIT6_DISP_LH(0xe3000000, 0x0080,
+ dst_reg, REG_0, REG_L,
+ EMIT_CONST_U64(imm));
+ } else {
+ /* lgrl %w0,imm */
+ EMIT6_PCREL_RILB(0xc4080000, REG_W0,
+ _EMIT_CONST_U64(imm));
+ jit->seen |= SEEN_LITERAL;
+ /* ngr %dst,%w0 */
+ EMIT4(0xb9800000, dst_reg, REG_W0);
+ }
break;
/*
* BPF_OR
@@ -751,9 +867,19 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT_ZERO(dst_reg);
break;
case BPF_ALU64 | BPF_OR | BPF_K: /* dst = dst | imm */
- /* og %dst,<d(imm)>(%l) */
- EMIT6_DISP_LH(0xe3000000, 0x0081, dst_reg, REG_0, REG_L,
- EMIT_CONST_U64(imm));
+ if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
+ /* og %dst,<d(imm)>(%l) */
+ EMIT6_DISP_LH(0xe3000000, 0x0081,
+ dst_reg, REG_0, REG_L,
+ EMIT_CONST_U64(imm));
+ } else {
+ /* lgrl %w0,imm */
+ EMIT6_PCREL_RILB(0xc4080000, REG_W0,
+ _EMIT_CONST_U64(imm));
+ jit->seen |= SEEN_LITERAL;
+ /* ogr %dst,%w0 */
+ EMIT4(0xb9810000, dst_reg, REG_W0);
+ }
break;
/*
* BPF_XOR
@@ -775,9 +901,19 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT_ZERO(dst_reg);
break;
case BPF_ALU64 | BPF_XOR | BPF_K: /* dst = dst ^ imm */
- /* xg %dst,<d(imm)>(%l) */
- EMIT6_DISP_LH(0xe3000000, 0x0082, dst_reg, REG_0, REG_L,
- EMIT_CONST_U64(imm));
+ if (!is_first_pass(jit) && can_use_ldisp_for_lit64(jit)) {
+ /* xg %dst,<d(imm)>(%l) */
+ EMIT6_DISP_LH(0xe3000000, 0x0082,
+ dst_reg, REG_0, REG_L,
+ EMIT_CONST_U64(imm));
+ } else {
+ /* lgrl %w0,imm */
+ EMIT6_PCREL_RILB(0xc4080000, REG_W0,
+ _EMIT_CONST_U64(imm));
+ jit->seen |= SEEN_LITERAL;
+ /* xgr %dst,%w0 */
+ EMIT4(0xb9820000, dst_reg, REG_W0);
+ }
break;
/*
* BPF_LSH
@@ -1023,9 +1159,8 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
REG_SET_SEEN(BPF_REG_5);
jit->seen |= SEEN_FUNC;
- /* lg %w1,<d(imm)>(%l) */
- EMIT6_DISP_LH(0xe3000000, 0x0004, REG_W1, REG_0, REG_L,
- EMIT_CONST_U64(func));
+ /* lgrl %w1,func */
+ EMIT6_PCREL_RILB(0xc4080000, REG_W1, _EMIT_CONST_U64(func));
if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable) {
/* brasl %r14,__s390_indirect_jump_r1 */
EMIT6_PCREL_RILB(0xc0050000, REG_14, jit->r1_thunk_ip);
@@ -1054,9 +1189,17 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
/* llgf %w1,map.max_entries(%b2) */
EMIT6_DISP_LH(0xe3000000, 0x0016, REG_W1, REG_0, BPF_REG_2,
offsetof(struct bpf_array, map.max_entries));
- /* clrj %b3,%w1,0xa,label0: if (u32)%b3 >= (u32)%w1 goto out */
- EMIT6_PCREL_LABEL(0xec000000, 0x0077, BPF_REG_3,
- REG_W1, 0, 0xa);
+ /* if ((u32)%b3 >= (u32)%w1) goto out; */
+ if (!is_first_pass(jit) && can_use_rel(jit, jit->labels[0])) {
+ /* clrj %b3,%w1,0xa,label0 */
+ EMIT6_PCREL_LABEL(0xec000000, 0x0077, BPF_REG_3,
+ REG_W1, 0, 0xa);
+ } else {
+ /* clr %b3,%w1 */
+ EMIT2(0x1500, BPF_REG_3, REG_W1);
+ /* brcl 0xa,label0 */
+ EMIT6_PCREL_RILC(0xc0040000, 0xa, jit->labels[0]);
+ }
/*
* if (tail_call_cnt++ > MAX_TAIL_CALL_CNT)
@@ -1071,9 +1214,16 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT4_IMM(0xa7080000, REG_W0, 1);
/* laal %w1,%w0,off(%r15) */
EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W1, REG_W0, REG_15, off);
- /* clij %w1,MAX_TAIL_CALL_CNT,0x2,label0 */
- EMIT6_PCREL_IMM_LABEL(0xec000000, 0x007f, REG_W1,
- MAX_TAIL_CALL_CNT, 0, 0x2);
+ if (!is_first_pass(jit) && can_use_rel(jit, jit->labels[0])) {
+ /* clij %w1,MAX_TAIL_CALL_CNT,0x2,label0 */
+ EMIT6_PCREL_IMM_LABEL(0xec000000, 0x007f, REG_W1,
+ MAX_TAIL_CALL_CNT, 0, 0x2);
+ } else {
+ /* clfi %w1,MAX_TAIL_CALL_CNT */
+ EMIT6_IMM(0xc20f0000, REG_W1, MAX_TAIL_CALL_CNT);
+ /* brcl 0x2,label0 */
+ EMIT6_PCREL_RILC(0xc0040000, 0x2, jit->labels[0]);
+ }
/*
* prog = array->ptrs[index];
@@ -1085,11 +1235,16 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
EMIT4(0xb9160000, REG_1, BPF_REG_3);
/* sllg %r1,%r1,3: %r1 *= 8 */
EMIT6_DISP_LH(0xeb000000, 0x000d, REG_1, REG_1, REG_0, 3);
- /* lg %r1,prog(%b2,%r1) */
- EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, BPF_REG_2,
+ /* ltg %r1,prog(%b2,%r1) */
+ EMIT6_DISP_LH(0xe3000000, 0x0002, REG_1, BPF_REG_2,
REG_1, offsetof(struct bpf_array, ptrs));
- /* clgij %r1,0,0x8,label0 */
- EMIT6_PCREL_IMM_LABEL(0xec000000, 0x007d, REG_1, 0, 0, 0x8);
+ if (!is_first_pass(jit) && can_use_rel(jit, jit->labels[0])) {
+ /* brc 0x8,label0 */
+ EMIT4_PCREL_RIC(0xa7040000, 0x8, jit->labels[0]);
+ } else {
+ /* brcl 0x8,label0 */
+ EMIT6_PCREL_RILC(0xc0040000, 0x8, jit->labels[0]);
+ }
/*
* Restore registers before calling function
@@ -1110,7 +1265,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
break;
case BPF_JMP | BPF_EXIT: /* return b0 */
last = (i == fp->len - 1) ? 1 : 0;
- if (last && !(jit->seen & SEEN_RET0))
+ if (last)
break;
/* j <exit> */
EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg);
@@ -1246,36 +1401,83 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
goto branch_oc;
branch_ks:
is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
- /* lgfi %w1,imm (load sign extend imm) */
- EMIT6_IMM(0xc0010000, REG_W1, imm);
- /* crj or cgrj %dst,%w1,mask,off */
- EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0076 : 0x0064),
- dst_reg, REG_W1, i, off, mask);
+ /* cfi or cgfi %dst,imm */
+ EMIT6_IMM(is_jmp32 ? 0xc20d0000 : 0xc20c0000,
+ dst_reg, imm);
+ if (!is_first_pass(jit) &&
+ can_use_rel(jit, addrs[i + off + 1])) {
+ /* brc mask,off */
+ EMIT4_PCREL_RIC(0xa7040000,
+ mask >> 12, addrs[i + off + 1]);
+ } else {
+ /* brcl mask,off */
+ EMIT6_PCREL_RILC(0xc0040000,
+ mask >> 12, addrs[i + off + 1]);
+ }
break;
branch_ku:
is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
- /* lgfi %w1,imm (load sign extend imm) */
- EMIT6_IMM(0xc0010000, REG_W1, imm);
- /* clrj or clgrj %dst,%w1,mask,off */
- EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0077 : 0x0065),
- dst_reg, REG_W1, i, off, mask);
+ /* clfi or clgfi %dst,imm */
+ EMIT6_IMM(is_jmp32 ? 0xc20f0000 : 0xc20e0000,
+ dst_reg, imm);
+ if (!is_first_pass(jit) &&
+ can_use_rel(jit, addrs[i + off + 1])) {
+ /* brc mask,off */
+ EMIT4_PCREL_RIC(0xa7040000,
+ mask >> 12, addrs[i + off + 1]);
+ } else {
+ /* brcl mask,off */
+ EMIT6_PCREL_RILC(0xc0040000,
+ mask >> 12, addrs[i + off + 1]);
+ }
break;
branch_xs:
is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
- /* crj or cgrj %dst,%src,mask,off */
- EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0076 : 0x0064),
- dst_reg, src_reg, i, off, mask);
+ if (!is_first_pass(jit) &&
+ can_use_rel(jit, addrs[i + off + 1])) {
+ /* crj or cgrj %dst,%src,mask,off */
+ EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0076 : 0x0064),
+ dst_reg, src_reg, i, off, mask);
+ } else {
+ /* cr or cgr %dst,%src */
+ if (is_jmp32)
+ EMIT2(0x1900, dst_reg, src_reg);
+ else
+ EMIT4(0xb9200000, dst_reg, src_reg);
+ /* brcl mask,off */
+ EMIT6_PCREL_RILC(0xc0040000,
+ mask >> 12, addrs[i + off + 1]);
+ }
break;
branch_xu:
is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
- /* clrj or clgrj %dst,%src,mask,off */
- EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0077 : 0x0065),
- dst_reg, src_reg, i, off, mask);
+ if (!is_first_pass(jit) &&
+ can_use_rel(jit, addrs[i + off + 1])) {
+ /* clrj or clgrj %dst,%src,mask,off */
+ EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0077 : 0x0065),
+ dst_reg, src_reg, i, off, mask);
+ } else {
+ /* clr or clgr %dst,%src */
+ if (is_jmp32)
+ EMIT2(0x1500, dst_reg, src_reg);
+ else
+ EMIT4(0xb9210000, dst_reg, src_reg);
+ /* brcl mask,off */
+ EMIT6_PCREL_RILC(0xc0040000,
+ mask >> 12, addrs[i + off + 1]);
+ }
break;
branch_oc:
- /* brc mask,jmp_off (branch instruction needs 4 bytes) */
- jmp_off = addrs[i + off + 1] - (addrs[i + 1] - 4);
- EMIT4_PCREL(0xa7040000 | mask << 8, jmp_off);
+ if (!is_first_pass(jit) &&
+ can_use_rel(jit, addrs[i + off + 1])) {
+ /* brc mask,off */
+ EMIT4_PCREL_RIC(0xa7040000,
+ mask >> 12, addrs[i + off + 1]);
+ } else {
+ /* brcl mask,off */
+ EMIT6_PCREL_RILC(0xc0040000,
+ mask >> 12, addrs[i + off + 1]);
+ }
break;
}
default: /* too complex, give up */
@@ -1286,28 +1488,67 @@ branch_oc:
}
/*
+ * Return whether new i-th instruction address does not violate any invariant
+ */
+static bool bpf_is_new_addr_sane(struct bpf_jit *jit, int i)
+{
+ /* On the first pass anything goes */
+ if (is_first_pass(jit))
+ return true;
+
+ /* The codegen pass must not change anything */
+ if (is_codegen_pass(jit))
+ return jit->addrs[i] == jit->prg;
+
+ /* Passes in between must not increase code size */
+ return jit->addrs[i] >= jit->prg;
+}
+
+/*
+ * Update the address of i-th instruction
+ */
+static int bpf_set_addr(struct bpf_jit *jit, int i)
+{
+ if (!bpf_is_new_addr_sane(jit, i))
+ return -1;
+ jit->addrs[i] = jit->prg;
+ return 0;
+}
+
+/*
* Compile eBPF program into s390x code
*/
static int bpf_jit_prog(struct bpf_jit *jit, struct bpf_prog *fp,
bool extra_pass)
{
- int i, insn_count;
+ int i, insn_count, lit32_size, lit64_size;
- jit->lit = jit->lit_start;
+ jit->lit32 = jit->lit32_start;
+ jit->lit64 = jit->lit64_start;
jit->prg = 0;
bpf_jit_prologue(jit, fp->aux->stack_depth);
+ if (bpf_set_addr(jit, 0) < 0)
+ return -1;
for (i = 0; i < fp->len; i += insn_count) {
insn_count = bpf_jit_insn(jit, fp, i, extra_pass);
if (insn_count < 0)
return -1;
/* Next instruction address */
- jit->addrs[i + insn_count] = jit->prg;
+ if (bpf_set_addr(jit, i + insn_count) < 0)
+ return -1;
}
bpf_jit_epilogue(jit, fp->aux->stack_depth);
- jit->lit_start = jit->prg;
- jit->size = jit->lit;
+ lit32_size = jit->lit32 - jit->lit32_start;
+ lit64_size = jit->lit64 - jit->lit64_start;
+ jit->lit32_start = jit->prg;
+ if (lit32_size)
+ jit->lit32_start = ALIGN(jit->lit32_start, 4);
+ jit->lit64_start = jit->lit32_start + lit32_size;
+ if (lit64_size)
+ jit->lit64_start = ALIGN(jit->lit64_start, 8);
+ jit->size = jit->lit64_start + lit64_size;
jit->size_prg = jit->prg;
return 0;
}
@@ -1369,7 +1610,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
}
memset(&jit, 0, sizeof(jit));
- jit.addrs = kcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL);
+ jit.addrs = kvcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL);
if (jit.addrs == NULL) {
fp = orig_fp;
goto out;
@@ -1388,12 +1629,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
/*
* Final pass: Allocate and generate program
*/
- if (jit.size >= BPF_SIZE_MAX) {
- fp = orig_fp;
- goto free_addrs;
- }
-
- header = bpf_jit_binary_alloc(jit.size, &jit.prg_buf, 2, jit_fill_hole);
+ header = bpf_jit_binary_alloc(jit.size, &jit.prg_buf, 8, jit_fill_hole);
if (!header) {
fp = orig_fp;
goto free_addrs;
@@ -1422,7 +1658,7 @@ skip_init_ctx:
if (!fp->is_func || extra_pass) {
bpf_prog_fill_jited_linfo(fp, jit.addrs + 1);
free_addrs:
- kfree(jit.addrs);
+ kvfree(jit.addrs);
kfree(jit_data);
fp->aux->jit_data = NULL;
}