forked from Minki/linux
d72714c1da
In order to branch around tail calls (due to out-of-bounds index,
exceeding tail call count or missing tail call target), JIT uses
label[0] field, which contains the address of the instruction following
the tail call. When there are multiple tail calls, label[0] value comes
from handling of a previous tail call, which is incorrect.
Fix by getting rid of label array and resolving the label address
locally: for all 3 branches that jump to it, emit 0 offsets at the
beginning, and then backpatch them with the correct value.
Also, do not use the long jump infrastructure: the tail call sequence
is known to be short, so make all 3 jumps short.
Fixes: 6651ee070b
("s390/bpf: implement bpf_tail_call() helper")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200909232141.3099367-1-iii@linux.ibm.com
1822 lines
48 KiB
C
1822 lines
48 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* BPF Jit compiler for s390.
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*
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* Minimum build requirements:
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*
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* - HAVE_MARCH_Z196_FEATURES: laal, laalg
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* - HAVE_MARCH_Z10_FEATURES: msfi, cgrj, clgrj
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* - HAVE_MARCH_Z9_109_FEATURES: alfi, llilf, clfi, oilf, nilf
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* - PACK_STACK
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* - 64BIT
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*
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* Copyright IBM Corp. 2012,2015
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*
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* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
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* Michael Holzheu <holzheu@linux.vnet.ibm.com>
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*/
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#define KMSG_COMPONENT "bpf_jit"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/netdevice.h>
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#include <linux/filter.h>
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#include <linux/init.h>
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#include <linux/bpf.h>
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#include <linux/mm.h>
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#include <linux/kernel.h>
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#include <asm/cacheflush.h>
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#include <asm/dis.h>
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#include <asm/facility.h>
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#include <asm/nospec-branch.h>
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#include <asm/set_memory.h>
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#include "bpf_jit.h"
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struct bpf_jit {
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u32 seen; /* Flags to remember seen eBPF instructions */
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u32 seen_reg[16]; /* Array to remember which registers are used */
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u32 *addrs; /* Array with relative instruction addresses */
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u8 *prg_buf; /* Start of program */
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int size; /* Size of program and literal pool */
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int size_prg; /* Size of program */
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int prg; /* Current position in program */
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int lit32_start; /* Start of 32-bit literal pool */
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int lit32; /* Current position in 32-bit literal pool */
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int lit64_start; /* Start of 64-bit literal pool */
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int lit64; /* Current position in 64-bit literal pool */
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int base_ip; /* Base address for literal pool */
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int exit_ip; /* Address of exit */
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int r1_thunk_ip; /* Address of expoline thunk for 'br %r1' */
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int r14_thunk_ip; /* Address of expoline thunk for 'br %r14' */
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int tail_call_start; /* Tail call start offset */
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int excnt; /* Number of exception table entries */
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};
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#define SEEN_MEM BIT(0) /* use mem[] for temporary storage */
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#define SEEN_LITERAL BIT(1) /* code uses literals */
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#define SEEN_FUNC BIT(2) /* calls C functions */
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#define SEEN_TAIL_CALL BIT(3) /* code uses tail calls */
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#define SEEN_STACK (SEEN_FUNC | SEEN_MEM)
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/*
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* s390 registers
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*/
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#define REG_W0 (MAX_BPF_JIT_REG + 0) /* Work register 1 (even) */
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#define REG_W1 (MAX_BPF_JIT_REG + 1) /* Work register 2 (odd) */
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#define REG_L (MAX_BPF_JIT_REG + 2) /* Literal pool register */
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#define REG_15 (MAX_BPF_JIT_REG + 3) /* Register 15 */
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#define REG_0 REG_W0 /* Register 0 */
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#define REG_1 REG_W1 /* Register 1 */
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#define REG_2 BPF_REG_1 /* Register 2 */
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#define REG_14 BPF_REG_0 /* Register 14 */
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/*
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* Mapping of BPF registers to s390 registers
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*/
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static const int reg2hex[] = {
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/* Return code */
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[BPF_REG_0] = 14,
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/* Function parameters */
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[BPF_REG_1] = 2,
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[BPF_REG_2] = 3,
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[BPF_REG_3] = 4,
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[BPF_REG_4] = 5,
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[BPF_REG_5] = 6,
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/* Call saved registers */
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[BPF_REG_6] = 7,
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[BPF_REG_7] = 8,
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[BPF_REG_8] = 9,
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[BPF_REG_9] = 10,
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/* BPF stack pointer */
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[BPF_REG_FP] = 13,
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/* Register for blinding */
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[BPF_REG_AX] = 12,
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/* Work registers for s390x backend */
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[REG_W0] = 0,
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[REG_W1] = 1,
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[REG_L] = 11,
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[REG_15] = 15,
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};
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static inline u32 reg(u32 dst_reg, u32 src_reg)
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{
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return reg2hex[dst_reg] << 4 | reg2hex[src_reg];
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}
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static inline u32 reg_high(u32 reg)
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{
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return reg2hex[reg] << 4;
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}
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static inline void reg_set_seen(struct bpf_jit *jit, u32 b1)
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{
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u32 r1 = reg2hex[b1];
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if (!jit->seen_reg[r1] && r1 >= 6 && r1 <= 15)
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jit->seen_reg[r1] = 1;
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}
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#define REG_SET_SEEN(b1) \
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({ \
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reg_set_seen(jit, b1); \
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})
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#define REG_SEEN(b1) jit->seen_reg[reg2hex[(b1)]]
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/*
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* EMIT macros for code generation
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*/
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#define _EMIT2(op) \
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({ \
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if (jit->prg_buf) \
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*(u16 *) (jit->prg_buf + jit->prg) = (op); \
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jit->prg += 2; \
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})
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#define EMIT2(op, b1, b2) \
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({ \
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_EMIT2((op) | reg(b1, b2)); \
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REG_SET_SEEN(b1); \
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REG_SET_SEEN(b2); \
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})
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#define _EMIT4(op) \
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({ \
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if (jit->prg_buf) \
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*(u32 *) (jit->prg_buf + jit->prg) = (op); \
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jit->prg += 4; \
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})
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#define EMIT4(op, b1, b2) \
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({ \
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_EMIT4((op) | reg(b1, b2)); \
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REG_SET_SEEN(b1); \
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REG_SET_SEEN(b2); \
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})
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#define EMIT4_RRF(op, b1, b2, b3) \
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({ \
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_EMIT4((op) | reg_high(b3) << 8 | reg(b1, b2)); \
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REG_SET_SEEN(b1); \
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REG_SET_SEEN(b2); \
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REG_SET_SEEN(b3); \
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})
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#define _EMIT4_DISP(op, disp) \
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({ \
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unsigned int __disp = (disp) & 0xfff; \
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_EMIT4((op) | __disp); \
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})
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#define EMIT4_DISP(op, b1, b2, disp) \
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({ \
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_EMIT4_DISP((op) | reg_high(b1) << 16 | \
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reg_high(b2) << 8, (disp)); \
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REG_SET_SEEN(b1); \
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REG_SET_SEEN(b2); \
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})
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#define EMIT4_IMM(op, b1, imm) \
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({ \
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unsigned int __imm = (imm) & 0xffff; \
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_EMIT4((op) | reg_high(b1) << 16 | __imm); \
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REG_SET_SEEN(b1); \
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})
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#define EMIT4_PCREL(op, pcrel) \
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({ \
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long __pcrel = ((pcrel) >> 1) & 0xffff; \
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_EMIT4((op) | __pcrel); \
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})
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#define EMIT4_PCREL_RIC(op, mask, target) \
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({ \
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int __rel = ((target) - jit->prg) / 2; \
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_EMIT4((op) | (mask) << 20 | (__rel & 0xffff)); \
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})
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#define _EMIT6(op1, op2) \
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({ \
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if (jit->prg_buf) { \
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*(u32 *) (jit->prg_buf + jit->prg) = (op1); \
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*(u16 *) (jit->prg_buf + jit->prg + 4) = (op2); \
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} \
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jit->prg += 6; \
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})
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#define _EMIT6_DISP(op1, op2, disp) \
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({ \
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unsigned int __disp = (disp) & 0xfff; \
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_EMIT6((op1) | __disp, op2); \
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})
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#define _EMIT6_DISP_LH(op1, op2, disp) \
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({ \
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u32 _disp = (u32) (disp); \
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unsigned int __disp_h = _disp & 0xff000; \
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unsigned int __disp_l = _disp & 0x00fff; \
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_EMIT6((op1) | __disp_l, (op2) | __disp_h >> 4); \
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})
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#define EMIT6_DISP_LH(op1, op2, b1, b2, b3, disp) \
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({ \
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_EMIT6_DISP_LH((op1) | reg(b1, b2) << 16 | \
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reg_high(b3) << 8, op2, disp); \
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REG_SET_SEEN(b1); \
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REG_SET_SEEN(b2); \
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REG_SET_SEEN(b3); \
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})
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#define EMIT6_PCREL_RIEB(op1, op2, b1, b2, mask, target) \
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({ \
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unsigned int rel = (int)((target) - jit->prg) / 2; \
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_EMIT6((op1) | reg(b1, b2) << 16 | (rel & 0xffff), \
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(op2) | (mask) << 12); \
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REG_SET_SEEN(b1); \
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REG_SET_SEEN(b2); \
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})
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#define EMIT6_PCREL_RIEC(op1, op2, b1, imm, mask, target) \
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({ \
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unsigned int rel = (int)((target) - jit->prg) / 2; \
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_EMIT6((op1) | (reg_high(b1) | (mask)) << 16 | \
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(rel & 0xffff), (op2) | ((imm) & 0xff) << 8); \
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REG_SET_SEEN(b1); \
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BUILD_BUG_ON(((unsigned long) (imm)) > 0xff); \
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})
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#define EMIT6_PCREL(op1, op2, b1, b2, i, off, mask) \
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({ \
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/* Branch instruction needs 6 bytes */ \
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int rel = (addrs[(i) + (off) + 1] - (addrs[(i) + 1] - 6)) / 2;\
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_EMIT6((op1) | reg(b1, b2) << 16 | (rel & 0xffff), (op2) | (mask));\
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REG_SET_SEEN(b1); \
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REG_SET_SEEN(b2); \
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})
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#define EMIT6_PCREL_RILB(op, b, target) \
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({ \
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unsigned int rel = (int)((target) - jit->prg) / 2; \
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_EMIT6((op) | reg_high(b) << 16 | rel >> 16, rel & 0xffff);\
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REG_SET_SEEN(b); \
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})
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#define EMIT6_PCREL_RIL(op, target) \
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({ \
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unsigned int rel = (int)((target) - jit->prg) / 2; \
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_EMIT6((op) | rel >> 16, rel & 0xffff); \
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})
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#define EMIT6_PCREL_RILC(op, mask, target) \
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({ \
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EMIT6_PCREL_RIL((op) | (mask) << 20, (target)); \
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})
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#define _EMIT6_IMM(op, imm) \
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({ \
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unsigned int __imm = (imm); \
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_EMIT6((op) | (__imm >> 16), __imm & 0xffff); \
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})
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#define EMIT6_IMM(op, b1, imm) \
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({ \
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_EMIT6_IMM((op) | reg_high(b1) << 16, imm); \
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REG_SET_SEEN(b1); \
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})
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#define _EMIT_CONST_U32(val) \
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({ \
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unsigned int ret; \
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ret = jit->lit32; \
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if (jit->prg_buf) \
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*(u32 *)(jit->prg_buf + jit->lit32) = (u32)(val);\
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jit->lit32 += 4; \
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ret; \
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})
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#define EMIT_CONST_U32(val) \
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({ \
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jit->seen |= SEEN_LITERAL; \
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_EMIT_CONST_U32(val) - jit->base_ip; \
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})
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#define _EMIT_CONST_U64(val) \
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({ \
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unsigned int ret; \
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ret = jit->lit64; \
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if (jit->prg_buf) \
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*(u64 *)(jit->prg_buf + jit->lit64) = (u64)(val);\
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jit->lit64 += 8; \
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ret; \
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})
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#define EMIT_CONST_U64(val) \
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({ \
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jit->seen |= SEEN_LITERAL; \
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_EMIT_CONST_U64(val) - jit->base_ip; \
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})
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#define EMIT_ZERO(b1) \
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({ \
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if (!fp->aux->verifier_zext) { \
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/* llgfr %dst,%dst (zero extend to 64 bit) */ \
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EMIT4(0xb9160000, b1, b1); \
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REG_SET_SEEN(b1); \
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} \
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})
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/*
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* Return whether this is the first pass. The first pass is special, since we
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* don't know any sizes yet, and thus must be conservative.
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*/
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static bool is_first_pass(struct bpf_jit *jit)
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{
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return jit->size == 0;
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}
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/*
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* Return whether this is the code generation pass. The code generation pass is
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* special, since we should change as little as possible.
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*/
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static bool is_codegen_pass(struct bpf_jit *jit)
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{
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return jit->prg_buf;
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}
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/*
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* Return whether "rel" can be encoded as a short PC-relative offset
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*/
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static bool is_valid_rel(int rel)
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{
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return rel >= -65536 && rel <= 65534;
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}
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/*
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* Return whether "off" can be reached using a short PC-relative offset
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*/
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static bool can_use_rel(struct bpf_jit *jit, int off)
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{
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return is_valid_rel(off - jit->prg);
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}
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/*
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* Return whether given displacement can be encoded using
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* Long-Displacement Facility
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*/
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static bool is_valid_ldisp(int disp)
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{
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return disp >= -524288 && disp <= 524287;
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}
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/*
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* Return whether the next 32-bit literal pool entry can be referenced using
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* Long-Displacement Facility
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*/
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static bool can_use_ldisp_for_lit32(struct bpf_jit *jit)
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{
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return is_valid_ldisp(jit->lit32 - jit->base_ip);
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}
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/*
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* Return whether the next 64-bit literal pool entry can be referenced using
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* Long-Displacement Facility
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*/
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static bool can_use_ldisp_for_lit64(struct bpf_jit *jit)
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{
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return is_valid_ldisp(jit->lit64 - jit->base_ip);
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}
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/*
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* Fill whole space with illegal instructions
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*/
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static void jit_fill_hole(void *area, unsigned int size)
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{
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memset(area, 0, size);
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}
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/*
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* Save registers from "rs" (register start) to "re" (register end) on stack
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*/
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static void save_regs(struct bpf_jit *jit, u32 rs, u32 re)
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{
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u32 off = STK_OFF_R6 + (rs - 6) * 8;
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if (rs == re)
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/* stg %rs,off(%r15) */
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_EMIT6(0xe300f000 | rs << 20 | off, 0x0024);
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else
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/* stmg %rs,%re,off(%r15) */
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_EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0024, off);
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}
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/*
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* Restore registers from "rs" (register start) to "re" (register end) on stack
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*/
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static void restore_regs(struct bpf_jit *jit, u32 rs, u32 re, u32 stack_depth)
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{
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u32 off = STK_OFF_R6 + (rs - 6) * 8;
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if (jit->seen & SEEN_STACK)
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off += STK_OFF + stack_depth;
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if (rs == re)
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/* lg %rs,off(%r15) */
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_EMIT6(0xe300f000 | rs << 20 | off, 0x0004);
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else
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/* lmg %rs,%re,off(%r15) */
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_EMIT6_DISP(0xeb00f000 | rs << 20 | re << 16, 0x0004, off);
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}
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/*
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* Return first seen register (from start)
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*/
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static int get_start(struct bpf_jit *jit, int start)
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{
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int i;
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for (i = start; i <= 15; i++) {
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if (jit->seen_reg[i])
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return i;
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}
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return 0;
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}
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/*
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* Return last seen register (from start) (gap >= 2)
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*/
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static int get_end(struct bpf_jit *jit, int start)
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{
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int i;
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for (i = start; i < 15; i++) {
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if (!jit->seen_reg[i] && !jit->seen_reg[i + 1])
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return i - 1;
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}
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return jit->seen_reg[15] ? 15 : 14;
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}
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#define REGS_SAVE 1
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#define REGS_RESTORE 0
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/*
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* Save and restore clobbered registers (6-15) on stack.
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* We save/restore registers in chunks with gap >= 2 registers.
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*/
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static void save_restore_regs(struct bpf_jit *jit, int op, u32 stack_depth)
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{
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const int last = 15, save_restore_size = 6;
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int re = 6, rs;
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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)
|
|
break;
|
|
re = get_end(jit, rs + 1);
|
|
if (op == REGS_SAVE)
|
|
save_regs(jit, rs, re);
|
|
else
|
|
restore_regs(jit, rs, re, stack_depth);
|
|
re++;
|
|
} while (re <= last);
|
|
}
|
|
|
|
static void bpf_skip(struct bpf_jit *jit, int size)
|
|
{
|
|
if (size >= 6 && !is_valid_rel(size)) {
|
|
/* brcl 0xf,size */
|
|
EMIT6_PCREL_RIL(0xc0f4000000, size);
|
|
size -= 6;
|
|
} else if (size >= 4 && is_valid_rel(size)) {
|
|
/* brc 0xf,size */
|
|
EMIT4_PCREL(0xa7f40000, size);
|
|
size -= 4;
|
|
}
|
|
while (size >= 2) {
|
|
/* bcr 0,%0 */
|
|
_EMIT2(0x0700);
|
|
size -= 2;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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, u32 stack_depth)
|
|
{
|
|
if (jit->seen & SEEN_TAIL_CALL) {
|
|
/* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */
|
|
_EMIT6(0xd703f000 | STK_OFF_TCCNT, 0xf000 | STK_OFF_TCCNT);
|
|
} else {
|
|
/*
|
|
* There are no tail calls. Insert nops in order to have
|
|
* tail_call_start at a predictable offset.
|
|
*/
|
|
bpf_skip(jit, 6);
|
|
}
|
|
/* Tail calls have to skip above initialization */
|
|
jit->tail_call_start = jit->prg;
|
|
/* Save registers */
|
|
save_restore_regs(jit, REGS_SAVE, stack_depth);
|
|
/* Setup literal pool */
|
|
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 (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 (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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Function epilogue
|
|
*/
|
|
static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth)
|
|
{
|
|
jit->exit_ip = jit->prg;
|
|
/* Load exit code: lgr %r2,%b0 */
|
|
EMIT4(0xb9040000, REG_2, BPF_REG_0);
|
|
/* Restore registers */
|
|
save_restore_regs(jit, REGS_RESTORE, stack_depth);
|
|
if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable) {
|
|
jit->r14_thunk_ip = jit->prg;
|
|
/* Generate __s390_indirect_jump_r14 thunk */
|
|
if (test_facility(35)) {
|
|
/* exrl %r0,.+10 */
|
|
EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10);
|
|
} else {
|
|
/* larl %r1,.+14 */
|
|
EMIT6_PCREL_RILB(0xc0000000, REG_1, jit->prg + 14);
|
|
/* ex 0,0(%r1) */
|
|
EMIT4_DISP(0x44000000, REG_0, REG_1, 0);
|
|
}
|
|
/* j . */
|
|
EMIT4_PCREL(0xa7f40000, 0);
|
|
}
|
|
/* br %r14 */
|
|
_EMIT2(0x07fe);
|
|
|
|
if (__is_defined(CC_USING_EXPOLINE) && !nospec_disable &&
|
|
(is_first_pass(jit) || (jit->seen & SEEN_FUNC))) {
|
|
jit->r1_thunk_ip = jit->prg;
|
|
/* Generate __s390_indirect_jump_r1 thunk */
|
|
if (test_facility(35)) {
|
|
/* exrl %r0,.+10 */
|
|
EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10);
|
|
/* j . */
|
|
EMIT4_PCREL(0xa7f40000, 0);
|
|
/* br %r1 */
|
|
_EMIT2(0x07f1);
|
|
} else {
|
|
/* ex 0,S390_lowcore.br_r1_tampoline */
|
|
EMIT4_DISP(0x44000000, REG_0, REG_0,
|
|
offsetof(struct lowcore, br_r1_trampoline));
|
|
/* j . */
|
|
EMIT4_PCREL(0xa7f40000, 0);
|
|
}
|
|
}
|
|
}
|
|
|
|
static int get_probe_mem_regno(const u8 *insn)
|
|
{
|
|
/*
|
|
* insn must point to llgc, llgh, llgf or lg, which have destination
|
|
* register at the same position.
|
|
*/
|
|
if (insn[0] != 0xe3) /* common llgc, llgh, llgf and lg prefix */
|
|
return -1;
|
|
if (insn[5] != 0x90 && /* llgc */
|
|
insn[5] != 0x91 && /* llgh */
|
|
insn[5] != 0x16 && /* llgf */
|
|
insn[5] != 0x04) /* lg */
|
|
return -1;
|
|
return insn[1] >> 4;
|
|
}
|
|
|
|
static bool ex_handler_bpf(const struct exception_table_entry *x,
|
|
struct pt_regs *regs)
|
|
{
|
|
int regno;
|
|
u8 *insn;
|
|
|
|
regs->psw.addr = extable_fixup(x);
|
|
insn = (u8 *)__rewind_psw(regs->psw, regs->int_code >> 16);
|
|
regno = get_probe_mem_regno(insn);
|
|
if (WARN_ON_ONCE(regno < 0))
|
|
/* JIT bug - unexpected instruction. */
|
|
return false;
|
|
regs->gprs[regno] = 0;
|
|
return true;
|
|
}
|
|
|
|
static int bpf_jit_probe_mem(struct bpf_jit *jit, struct bpf_prog *fp,
|
|
int probe_prg, int nop_prg)
|
|
{
|
|
struct exception_table_entry *ex;
|
|
s64 delta;
|
|
u8 *insn;
|
|
int prg;
|
|
int i;
|
|
|
|
if (!fp->aux->extable)
|
|
/* Do nothing during early JIT passes. */
|
|
return 0;
|
|
insn = jit->prg_buf + probe_prg;
|
|
if (WARN_ON_ONCE(get_probe_mem_regno(insn) < 0))
|
|
/* JIT bug - unexpected probe instruction. */
|
|
return -1;
|
|
if (WARN_ON_ONCE(probe_prg + insn_length(*insn) != nop_prg))
|
|
/* JIT bug - gap between probe and nop instructions. */
|
|
return -1;
|
|
for (i = 0; i < 2; i++) {
|
|
if (WARN_ON_ONCE(jit->excnt >= fp->aux->num_exentries))
|
|
/* Verifier bug - not enough entries. */
|
|
return -1;
|
|
ex = &fp->aux->extable[jit->excnt];
|
|
/* Add extable entries for probe and nop instructions. */
|
|
prg = i == 0 ? probe_prg : nop_prg;
|
|
delta = jit->prg_buf + prg - (u8 *)&ex->insn;
|
|
if (WARN_ON_ONCE(delta < INT_MIN || delta > INT_MAX))
|
|
/* JIT bug - code and extable must be close. */
|
|
return -1;
|
|
ex->insn = delta;
|
|
/*
|
|
* Always land on the nop. Note that extable infrastructure
|
|
* ignores fixup field, it is handled by ex_handler_bpf().
|
|
*/
|
|
delta = jit->prg_buf + nop_prg - (u8 *)&ex->fixup;
|
|
if (WARN_ON_ONCE(delta < INT_MIN || delta > INT_MAX))
|
|
/* JIT bug - landing pad and extable must be close. */
|
|
return -1;
|
|
ex->fixup = delta;
|
|
ex->handler = (u8 *)ex_handler_bpf - (u8 *)&ex->handler;
|
|
jit->excnt++;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Compile one eBPF instruction into s390x code
|
|
*
|
|
* NOTE: Use noinline because for gcov (-fprofile-arcs) gcc allocates a lot of
|
|
* stack space for the large switch statement.
|
|
*/
|
|
static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp,
|
|
int i, bool extra_pass, u32 stack_depth)
|
|
{
|
|
struct bpf_insn *insn = &fp->insnsi[i];
|
|
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;
|
|
int probe_prg = -1;
|
|
unsigned int mask;
|
|
int nop_prg;
|
|
int err;
|
|
|
|
if (BPF_CLASS(insn->code) == BPF_LDX &&
|
|
BPF_MODE(insn->code) == BPF_PROBE_MEM)
|
|
probe_prg = jit->prg;
|
|
|
|
switch (insn->code) {
|
|
/*
|
|
* BPF_MOV
|
|
*/
|
|
case BPF_ALU | BPF_MOV | BPF_X: /* dst = (u32) src */
|
|
/* llgfr %dst,%src */
|
|
EMIT4(0xb9160000, dst_reg, src_reg);
|
|
if (insn_is_zext(&insn[1]))
|
|
insn_count = 2;
|
|
break;
|
|
case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
|
|
/* lgr %dst,%src */
|
|
EMIT4(0xb9040000, dst_reg, src_reg);
|
|
break;
|
|
case BPF_ALU | BPF_MOV | BPF_K: /* dst = (u32) imm */
|
|
/* llilf %dst,imm */
|
|
EMIT6_IMM(0xc00f0000, dst_reg, imm);
|
|
if (insn_is_zext(&insn[1]))
|
|
insn_count = 2;
|
|
break;
|
|
case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = imm */
|
|
/* lgfi %dst,imm */
|
|
EMIT6_IMM(0xc0010000, dst_reg, imm);
|
|
break;
|
|
/*
|
|
* BPF_LD 64
|
|
*/
|
|
case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
|
|
{
|
|
/* 16 byte instruction that uses two 'struct bpf_insn' */
|
|
u64 imm64;
|
|
|
|
imm64 = (u64)(u32) insn[0].imm | ((u64)(u32) insn[1].imm) << 32;
|
|
/* lgrl %dst,imm */
|
|
EMIT6_PCREL_RILB(0xc4080000, dst_reg, _EMIT_CONST_U64(imm64));
|
|
insn_count = 2;
|
|
break;
|
|
}
|
|
/*
|
|
* BPF_ADD
|
|
*/
|
|
case BPF_ALU | BPF_ADD | BPF_X: /* dst = (u32) dst + (u32) src */
|
|
/* ar %dst,%src */
|
|
EMIT2(0x1a00, dst_reg, src_reg);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_ADD | BPF_X: /* dst = dst + src */
|
|
/* agr %dst,%src */
|
|
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);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_ADD | BPF_K: /* dst = dst + imm */
|
|
if (!imm)
|
|
break;
|
|
/* agfi %dst,imm */
|
|
EMIT6_IMM(0xc2080000, dst_reg, imm);
|
|
break;
|
|
/*
|
|
* BPF_SUB
|
|
*/
|
|
case BPF_ALU | BPF_SUB | BPF_X: /* dst = (u32) dst - (u32) src */
|
|
/* sr %dst,%src */
|
|
EMIT2(0x1b00, dst_reg, src_reg);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_SUB | BPF_X: /* dst = dst - src */
|
|
/* sgr %dst,%src */
|
|
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);
|
|
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);
|
|
break;
|
|
/*
|
|
* BPF_MUL
|
|
*/
|
|
case BPF_ALU | BPF_MUL | BPF_X: /* dst = (u32) dst * (u32) src */
|
|
/* msr %dst,%src */
|
|
EMIT4(0xb2520000, dst_reg, src_reg);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_MUL | BPF_X: /* dst = dst * src */
|
|
/* msgr %dst,%src */
|
|
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);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_MUL | BPF_K: /* dst = dst * imm */
|
|
if (imm == 1)
|
|
break;
|
|
/* msgfi %dst,imm */
|
|
EMIT6_IMM(0xc2000000, dst_reg, imm);
|
|
break;
|
|
/*
|
|
* BPF_DIV / BPF_MOD
|
|
*/
|
|
case BPF_ALU | BPF_DIV | BPF_X: /* dst = (u32) dst / (u32) src */
|
|
case BPF_ALU | BPF_MOD | BPF_X: /* dst = (u32) dst % (u32) src */
|
|
{
|
|
int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
|
|
|
|
/* lhi %w0,0 */
|
|
EMIT4_IMM(0xa7080000, REG_W0, 0);
|
|
/* lr %w1,%dst */
|
|
EMIT2(0x1800, REG_W1, dst_reg);
|
|
/* dlr %w0,%src */
|
|
EMIT4(0xb9970000, REG_W0, src_reg);
|
|
/* llgfr %dst,%rc */
|
|
EMIT4(0xb9160000, dst_reg, rc_reg);
|
|
if (insn_is_zext(&insn[1]))
|
|
insn_count = 2;
|
|
break;
|
|
}
|
|
case BPF_ALU64 | BPF_DIV | BPF_X: /* dst = dst / src */
|
|
case BPF_ALU64 | BPF_MOD | BPF_X: /* dst = dst % src */
|
|
{
|
|
int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
|
|
|
|
/* lghi %w0,0 */
|
|
EMIT4_IMM(0xa7090000, REG_W0, 0);
|
|
/* lgr %w1,%dst */
|
|
EMIT4(0xb9040000, REG_W1, dst_reg);
|
|
/* dlgr %w0,%dst */
|
|
EMIT4(0xb9870000, REG_W0, src_reg);
|
|
/* lgr %dst,%rc */
|
|
EMIT4(0xb9040000, dst_reg, rc_reg);
|
|
break;
|
|
}
|
|
case BPF_ALU | BPF_DIV | BPF_K: /* dst = (u32) dst / (u32) imm */
|
|
case BPF_ALU | BPF_MOD | BPF_K: /* dst = (u32) dst % (u32) imm */
|
|
{
|
|
int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
|
|
|
|
if (imm == 1) {
|
|
if (BPF_OP(insn->code) == BPF_MOD)
|
|
/* lhgi %dst,0 */
|
|
EMIT4_IMM(0xa7090000, dst_reg, 0);
|
|
break;
|
|
}
|
|
/* lhi %w0,0 */
|
|
EMIT4_IMM(0xa7080000, REG_W0, 0);
|
|
/* lr %w1,%dst */
|
|
EMIT2(0x1800, REG_W1, dst_reg);
|
|
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]))
|
|
insn_count = 2;
|
|
break;
|
|
}
|
|
case BPF_ALU64 | BPF_DIV | BPF_K: /* dst = dst / imm */
|
|
case BPF_ALU64 | BPF_MOD | BPF_K: /* dst = dst % imm */
|
|
{
|
|
int rc_reg = BPF_OP(insn->code) == BPF_DIV ? REG_W1 : REG_W0;
|
|
|
|
if (imm == 1) {
|
|
if (BPF_OP(insn->code) == BPF_MOD)
|
|
/* lhgi %dst,0 */
|
|
EMIT4_IMM(0xa7090000, dst_reg, 0);
|
|
break;
|
|
}
|
|
/* lghi %w0,0 */
|
|
EMIT4_IMM(0xa7090000, REG_W0, 0);
|
|
/* lgr %w1,%dst */
|
|
EMIT4(0xb9040000, REG_W1, dst_reg);
|
|
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;
|
|
}
|
|
/*
|
|
* BPF_AND
|
|
*/
|
|
case BPF_ALU | BPF_AND | BPF_X: /* dst = (u32) dst & (u32) src */
|
|
/* nr %dst,%src */
|
|
EMIT2(0x1400, dst_reg, src_reg);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
|
|
/* ngr %dst,%src */
|
|
EMIT4(0xb9800000, dst_reg, src_reg);
|
|
break;
|
|
case BPF_ALU | BPF_AND | BPF_K: /* dst = (u32) dst & (u32) imm */
|
|
/* nilf %dst,imm */
|
|
EMIT6_IMM(0xc00b0000, dst_reg, imm);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & 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
|
|
*/
|
|
case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
|
|
/* or %dst,%src */
|
|
EMIT2(0x1600, dst_reg, src_reg);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
|
|
/* ogr %dst,%src */
|
|
EMIT4(0xb9810000, dst_reg, src_reg);
|
|
break;
|
|
case BPF_ALU | BPF_OR | BPF_K: /* dst = (u32) dst | (u32) imm */
|
|
/* oilf %dst,imm */
|
|
EMIT6_IMM(0xc00d0000, dst_reg, imm);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_OR | BPF_K: /* dst = dst | 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
|
|
*/
|
|
case BPF_ALU | BPF_XOR | BPF_X: /* dst = (u32) dst ^ (u32) src */
|
|
/* xr %dst,%src */
|
|
EMIT2(0x1700, dst_reg, src_reg);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_XOR | BPF_X: /* dst = dst ^ src */
|
|
/* xgr %dst,%src */
|
|
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);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_XOR | BPF_K: /* dst = dst ^ 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
|
|
*/
|
|
case BPF_ALU | BPF_LSH | BPF_X: /* dst = (u32) dst << (u32) src */
|
|
/* sll %dst,0(%src) */
|
|
EMIT4_DISP(0x89000000, dst_reg, src_reg, 0);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_LSH | BPF_X: /* dst = dst << src */
|
|
/* sllg %dst,%dst,0(%src) */
|
|
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);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_LSH | BPF_K: /* dst = dst << imm */
|
|
if (imm == 0)
|
|
break;
|
|
/* sllg %dst,%dst,imm(%r0) */
|
|
EMIT6_DISP_LH(0xeb000000, 0x000d, dst_reg, dst_reg, REG_0, imm);
|
|
break;
|
|
/*
|
|
* BPF_RSH
|
|
*/
|
|
case BPF_ALU | BPF_RSH | BPF_X: /* dst = (u32) dst >> (u32) src */
|
|
/* srl %dst,0(%src) */
|
|
EMIT4_DISP(0x88000000, dst_reg, src_reg, 0);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_RSH | BPF_X: /* dst = dst >> src */
|
|
/* srlg %dst,%dst,0(%src) */
|
|
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);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_RSH | BPF_K: /* dst = dst >> imm */
|
|
if (imm == 0)
|
|
break;
|
|
/* srlg %dst,%dst,imm(%r0) */
|
|
EMIT6_DISP_LH(0xeb000000, 0x000c, dst_reg, dst_reg, REG_0, imm);
|
|
break;
|
|
/*
|
|
* BPF_ARSH
|
|
*/
|
|
case BPF_ALU | BPF_ARSH | BPF_X: /* ((s32) dst) >>= src */
|
|
/* sra %dst,%dst,0(%src) */
|
|
EMIT4_DISP(0x8a000000, dst_reg, src_reg, 0);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_ARSH | BPF_X: /* ((s64) dst) >>= src */
|
|
/* srag %dst,%dst,0(%src) */
|
|
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);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_ARSH | BPF_K: /* ((s64) dst) >>= imm */
|
|
if (imm == 0)
|
|
break;
|
|
/* srag %dst,%dst,imm(%r0) */
|
|
EMIT6_DISP_LH(0xeb000000, 0x000a, dst_reg, dst_reg, REG_0, imm);
|
|
break;
|
|
/*
|
|
* BPF_NEG
|
|
*/
|
|
case BPF_ALU | BPF_NEG: /* dst = (u32) -dst */
|
|
/* lcr %dst,%dst */
|
|
EMIT2(0x1300, dst_reg, dst_reg);
|
|
EMIT_ZERO(dst_reg);
|
|
break;
|
|
case BPF_ALU64 | BPF_NEG: /* dst = -dst */
|
|
/* lcgr %dst,%dst */
|
|
EMIT4(0xb9030000, dst_reg, dst_reg);
|
|
break;
|
|
/*
|
|
* BPF_FROM_BE/LE
|
|
*/
|
|
case BPF_ALU | BPF_END | BPF_FROM_BE:
|
|
/* s390 is big endian, therefore only clear high order bytes */
|
|
switch (imm) {
|
|
case 16: /* dst = (u16) cpu_to_be16(dst) */
|
|
/* llghr %dst,%dst */
|
|
EMIT4(0xb9850000, dst_reg, dst_reg);
|
|
if (insn_is_zext(&insn[1]))
|
|
insn_count = 2;
|
|
break;
|
|
case 32: /* dst = (u32) cpu_to_be32(dst) */
|
|
if (!fp->aux->verifier_zext)
|
|
/* llgfr %dst,%dst */
|
|
EMIT4(0xb9160000, dst_reg, dst_reg);
|
|
break;
|
|
case 64: /* dst = (u64) cpu_to_be64(dst) */
|
|
break;
|
|
}
|
|
break;
|
|
case BPF_ALU | BPF_END | BPF_FROM_LE:
|
|
switch (imm) {
|
|
case 16: /* dst = (u16) cpu_to_le16(dst) */
|
|
/* lrvr %dst,%dst */
|
|
EMIT4(0xb91f0000, dst_reg, dst_reg);
|
|
/* srl %dst,16(%r0) */
|
|
EMIT4_DISP(0x88000000, dst_reg, REG_0, 16);
|
|
/* llghr %dst,%dst */
|
|
EMIT4(0xb9850000, dst_reg, dst_reg);
|
|
if (insn_is_zext(&insn[1]))
|
|
insn_count = 2;
|
|
break;
|
|
case 32: /* dst = (u32) cpu_to_le32(dst) */
|
|
/* lrvr %dst,%dst */
|
|
EMIT4(0xb91f0000, dst_reg, dst_reg);
|
|
if (!fp->aux->verifier_zext)
|
|
/* llgfr %dst,%dst */
|
|
EMIT4(0xb9160000, dst_reg, dst_reg);
|
|
break;
|
|
case 64: /* dst = (u64) cpu_to_le64(dst) */
|
|
/* lrvgr %dst,%dst */
|
|
EMIT4(0xb90f0000, dst_reg, dst_reg);
|
|
break;
|
|
}
|
|
break;
|
|
/*
|
|
* BPF_ST(X)
|
|
*/
|
|
case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src_reg */
|
|
/* stcy %src,off(%dst) */
|
|
EMIT6_DISP_LH(0xe3000000, 0x0072, src_reg, dst_reg, REG_0, off);
|
|
jit->seen |= SEEN_MEM;
|
|
break;
|
|
case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
|
|
/* sthy %src,off(%dst) */
|
|
EMIT6_DISP_LH(0xe3000000, 0x0070, src_reg, dst_reg, REG_0, off);
|
|
jit->seen |= SEEN_MEM;
|
|
break;
|
|
case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
|
|
/* sty %src,off(%dst) */
|
|
EMIT6_DISP_LH(0xe3000000, 0x0050, src_reg, dst_reg, REG_0, off);
|
|
jit->seen |= SEEN_MEM;
|
|
break;
|
|
case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
|
|
/* stg %src,off(%dst) */
|
|
EMIT6_DISP_LH(0xe3000000, 0x0024, src_reg, dst_reg, REG_0, off);
|
|
jit->seen |= SEEN_MEM;
|
|
break;
|
|
case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
|
|
/* lhi %w0,imm */
|
|
EMIT4_IMM(0xa7080000, REG_W0, (u8) imm);
|
|
/* stcy %w0,off(dst) */
|
|
EMIT6_DISP_LH(0xe3000000, 0x0072, REG_W0, dst_reg, REG_0, off);
|
|
jit->seen |= SEEN_MEM;
|
|
break;
|
|
case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
|
|
/* lhi %w0,imm */
|
|
EMIT4_IMM(0xa7080000, REG_W0, (u16) imm);
|
|
/* sthy %w0,off(dst) */
|
|
EMIT6_DISP_LH(0xe3000000, 0x0070, REG_W0, dst_reg, REG_0, off);
|
|
jit->seen |= SEEN_MEM;
|
|
break;
|
|
case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
|
|
/* llilf %w0,imm */
|
|
EMIT6_IMM(0xc00f0000, REG_W0, (u32) imm);
|
|
/* sty %w0,off(%dst) */
|
|
EMIT6_DISP_LH(0xe3000000, 0x0050, REG_W0, dst_reg, REG_0, off);
|
|
jit->seen |= SEEN_MEM;
|
|
break;
|
|
case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
|
|
/* lgfi %w0,imm */
|
|
EMIT6_IMM(0xc0010000, REG_W0, imm);
|
|
/* stg %w0,off(%dst) */
|
|
EMIT6_DISP_LH(0xe3000000, 0x0024, REG_W0, dst_reg, REG_0, off);
|
|
jit->seen |= SEEN_MEM;
|
|
break;
|
|
/*
|
|
* BPF_STX XADD (atomic_add)
|
|
*/
|
|
case BPF_STX | BPF_XADD | BPF_W: /* *(u32 *)(dst + off) += src */
|
|
/* laal %w0,%src,off(%dst) */
|
|
EMIT6_DISP_LH(0xeb000000, 0x00fa, REG_W0, src_reg,
|
|
dst_reg, off);
|
|
jit->seen |= SEEN_MEM;
|
|
break;
|
|
case BPF_STX | BPF_XADD | BPF_DW: /* *(u64 *)(dst + off) += src */
|
|
/* laalg %w0,%src,off(%dst) */
|
|
EMIT6_DISP_LH(0xeb000000, 0x00ea, REG_W0, src_reg,
|
|
dst_reg, off);
|
|
jit->seen |= SEEN_MEM;
|
|
break;
|
|
/*
|
|
* BPF_LDX
|
|
*/
|
|
case BPF_LDX | BPF_MEM | BPF_B: /* dst = *(u8 *)(ul) (src + off) */
|
|
case BPF_LDX | BPF_PROBE_MEM | BPF_B:
|
|
/* llgc %dst,0(off,%src) */
|
|
EMIT6_DISP_LH(0xe3000000, 0x0090, dst_reg, src_reg, REG_0, off);
|
|
jit->seen |= SEEN_MEM;
|
|
if (insn_is_zext(&insn[1]))
|
|
insn_count = 2;
|
|
break;
|
|
case BPF_LDX | BPF_MEM | BPF_H: /* dst = *(u16 *)(ul) (src + off) */
|
|
case BPF_LDX | BPF_PROBE_MEM | BPF_H:
|
|
/* llgh %dst,0(off,%src) */
|
|
EMIT6_DISP_LH(0xe3000000, 0x0091, dst_reg, src_reg, REG_0, off);
|
|
jit->seen |= SEEN_MEM;
|
|
if (insn_is_zext(&insn[1]))
|
|
insn_count = 2;
|
|
break;
|
|
case BPF_LDX | BPF_MEM | BPF_W: /* dst = *(u32 *)(ul) (src + off) */
|
|
case BPF_LDX | BPF_PROBE_MEM | BPF_W:
|
|
/* llgf %dst,off(%src) */
|
|
jit->seen |= SEEN_MEM;
|
|
EMIT6_DISP_LH(0xe3000000, 0x0016, dst_reg, src_reg, REG_0, off);
|
|
if (insn_is_zext(&insn[1]))
|
|
insn_count = 2;
|
|
break;
|
|
case BPF_LDX | BPF_MEM | BPF_DW: /* dst = *(u64 *)(ul) (src + off) */
|
|
case BPF_LDX | BPF_PROBE_MEM | BPF_DW:
|
|
/* lg %dst,0(off,%src) */
|
|
jit->seen |= SEEN_MEM;
|
|
EMIT6_DISP_LH(0xe3000000, 0x0004, dst_reg, src_reg, REG_0, off);
|
|
break;
|
|
/*
|
|
* BPF_JMP / CALL
|
|
*/
|
|
case BPF_JMP | BPF_CALL:
|
|
{
|
|
u64 func;
|
|
bool func_addr_fixed;
|
|
int ret;
|
|
|
|
ret = bpf_jit_get_func_addr(fp, insn, extra_pass,
|
|
&func, &func_addr_fixed);
|
|
if (ret < 0)
|
|
return -1;
|
|
|
|
REG_SET_SEEN(BPF_REG_5);
|
|
jit->seen |= SEEN_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);
|
|
} else {
|
|
/* basr %r14,%w1 */
|
|
EMIT2(0x0d00, REG_14, REG_W1);
|
|
}
|
|
/* lgr %b0,%r2: load return value into %b0 */
|
|
EMIT4(0xb9040000, BPF_REG_0, REG_2);
|
|
break;
|
|
}
|
|
case BPF_JMP | BPF_TAIL_CALL: {
|
|
int patch_1_clrj, patch_2_clij, patch_3_brc;
|
|
|
|
/*
|
|
* Implicit input:
|
|
* B1: pointer to ctx
|
|
* B2: pointer to bpf_array
|
|
* B3: index in bpf_array
|
|
*/
|
|
jit->seen |= SEEN_TAIL_CALL;
|
|
|
|
/*
|
|
* if (index >= array->map.max_entries)
|
|
* goto out;
|
|
*/
|
|
|
|
/* 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));
|
|
/* if ((u32)%b3 >= (u32)%w1) goto out; */
|
|
/* clrj %b3,%w1,0xa,out */
|
|
patch_1_clrj = jit->prg;
|
|
EMIT6_PCREL_RIEB(0xec000000, 0x0077, BPF_REG_3, REG_W1, 0xa,
|
|
jit->prg);
|
|
|
|
/*
|
|
* if (tail_call_cnt++ > MAX_TAIL_CALL_CNT)
|
|
* goto out;
|
|
*/
|
|
|
|
if (jit->seen & SEEN_STACK)
|
|
off = STK_OFF_TCCNT + STK_OFF + stack_depth;
|
|
else
|
|
off = STK_OFF_TCCNT;
|
|
/* lhi %w0,1 */
|
|
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,out */
|
|
patch_2_clij = jit->prg;
|
|
EMIT6_PCREL_RIEC(0xec000000, 0x007f, REG_W1, MAX_TAIL_CALL_CNT,
|
|
2, jit->prg);
|
|
|
|
/*
|
|
* prog = array->ptrs[index];
|
|
* if (prog == NULL)
|
|
* goto out;
|
|
*/
|
|
|
|
/* llgfr %r1,%b3: %r1 = (u32) index */
|
|
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);
|
|
/* ltg %r1,prog(%b2,%r1) */
|
|
EMIT6_DISP_LH(0xe3000000, 0x0002, REG_1, BPF_REG_2,
|
|
REG_1, offsetof(struct bpf_array, ptrs));
|
|
/* brc 0x8,out */
|
|
patch_3_brc = jit->prg;
|
|
EMIT4_PCREL_RIC(0xa7040000, 8, jit->prg);
|
|
|
|
/*
|
|
* Restore registers before calling function
|
|
*/
|
|
save_restore_regs(jit, REGS_RESTORE, stack_depth);
|
|
|
|
/*
|
|
* goto *(prog->bpf_func + tail_call_start);
|
|
*/
|
|
|
|
/* lg %r1,bpf_func(%r1) */
|
|
EMIT6_DISP_LH(0xe3000000, 0x0004, REG_1, REG_1, REG_0,
|
|
offsetof(struct bpf_prog, bpf_func));
|
|
/* bc 0xf,tail_call_start(%r1) */
|
|
_EMIT4(0x47f01000 + jit->tail_call_start);
|
|
/* out: */
|
|
if (jit->prg_buf) {
|
|
*(u16 *)(jit->prg_buf + patch_1_clrj + 2) =
|
|
(jit->prg - patch_1_clrj) >> 1;
|
|
*(u16 *)(jit->prg_buf + patch_2_clij + 2) =
|
|
(jit->prg - patch_2_clij) >> 1;
|
|
*(u16 *)(jit->prg_buf + patch_3_brc + 2) =
|
|
(jit->prg - patch_3_brc) >> 1;
|
|
}
|
|
break;
|
|
}
|
|
case BPF_JMP | BPF_EXIT: /* return b0 */
|
|
last = (i == fp->len - 1) ? 1 : 0;
|
|
if (last)
|
|
break;
|
|
if (!is_first_pass(jit) && can_use_rel(jit, jit->exit_ip))
|
|
/* brc 0xf, <exit> */
|
|
EMIT4_PCREL_RIC(0xa7040000, 0xf, jit->exit_ip);
|
|
else
|
|
/* brcl 0xf, <exit> */
|
|
EMIT6_PCREL_RILC(0xc0040000, 0xf, jit->exit_ip);
|
|
break;
|
|
/*
|
|
* Branch relative (number of skipped instructions) to offset on
|
|
* condition.
|
|
*
|
|
* Condition code to mask mapping:
|
|
*
|
|
* CC | Description | Mask
|
|
* ------------------------------
|
|
* 0 | Operands equal | 8
|
|
* 1 | First operand low | 4
|
|
* 2 | First operand high | 2
|
|
* 3 | Unused | 1
|
|
*
|
|
* For s390x relative branches: ip = ip + off_bytes
|
|
* For BPF relative branches: insn = insn + off_insns + 1
|
|
*
|
|
* For example for s390x with offset 0 we jump to the branch
|
|
* instruction itself (loop) and for BPF with offset 0 we
|
|
* branch to the instruction behind the branch.
|
|
*/
|
|
case BPF_JMP | BPF_JA: /* if (true) */
|
|
mask = 0xf000; /* j */
|
|
goto branch_oc;
|
|
case BPF_JMP | BPF_JSGT | BPF_K: /* ((s64) dst > (s64) imm) */
|
|
case BPF_JMP32 | BPF_JSGT | BPF_K: /* ((s32) dst > (s32) imm) */
|
|
mask = 0x2000; /* jh */
|
|
goto branch_ks;
|
|
case BPF_JMP | BPF_JSLT | BPF_K: /* ((s64) dst < (s64) imm) */
|
|
case BPF_JMP32 | BPF_JSLT | BPF_K: /* ((s32) dst < (s32) imm) */
|
|
mask = 0x4000; /* jl */
|
|
goto branch_ks;
|
|
case BPF_JMP | BPF_JSGE | BPF_K: /* ((s64) dst >= (s64) imm) */
|
|
case BPF_JMP32 | BPF_JSGE | BPF_K: /* ((s32) dst >= (s32) imm) */
|
|
mask = 0xa000; /* jhe */
|
|
goto branch_ks;
|
|
case BPF_JMP | BPF_JSLE | BPF_K: /* ((s64) dst <= (s64) imm) */
|
|
case BPF_JMP32 | BPF_JSLE | BPF_K: /* ((s32) dst <= (s32) imm) */
|
|
mask = 0xc000; /* jle */
|
|
goto branch_ks;
|
|
case BPF_JMP | BPF_JGT | BPF_K: /* (dst_reg > imm) */
|
|
case BPF_JMP32 | BPF_JGT | BPF_K: /* ((u32) dst_reg > (u32) imm) */
|
|
mask = 0x2000; /* jh */
|
|
goto branch_ku;
|
|
case BPF_JMP | BPF_JLT | BPF_K: /* (dst_reg < imm) */
|
|
case BPF_JMP32 | BPF_JLT | BPF_K: /* ((u32) dst_reg < (u32) imm) */
|
|
mask = 0x4000; /* jl */
|
|
goto branch_ku;
|
|
case BPF_JMP | BPF_JGE | BPF_K: /* (dst_reg >= imm) */
|
|
case BPF_JMP32 | BPF_JGE | BPF_K: /* ((u32) dst_reg >= (u32) imm) */
|
|
mask = 0xa000; /* jhe */
|
|
goto branch_ku;
|
|
case BPF_JMP | BPF_JLE | BPF_K: /* (dst_reg <= imm) */
|
|
case BPF_JMP32 | BPF_JLE | BPF_K: /* ((u32) dst_reg <= (u32) imm) */
|
|
mask = 0xc000; /* jle */
|
|
goto branch_ku;
|
|
case BPF_JMP | BPF_JNE | BPF_K: /* (dst_reg != imm) */
|
|
case BPF_JMP32 | BPF_JNE | BPF_K: /* ((u32) dst_reg != (u32) imm) */
|
|
mask = 0x7000; /* jne */
|
|
goto branch_ku;
|
|
case BPF_JMP | BPF_JEQ | BPF_K: /* (dst_reg == imm) */
|
|
case BPF_JMP32 | BPF_JEQ | BPF_K: /* ((u32) dst_reg == (u32) imm) */
|
|
mask = 0x8000; /* je */
|
|
goto branch_ku;
|
|
case BPF_JMP | BPF_JSET | BPF_K: /* (dst_reg & imm) */
|
|
case BPF_JMP32 | BPF_JSET | BPF_K: /* ((u32) dst_reg & (u32) imm) */
|
|
mask = 0x7000; /* jnz */
|
|
if (BPF_CLASS(insn->code) == BPF_JMP32) {
|
|
/* llilf %w1,imm (load zero extend imm) */
|
|
EMIT6_IMM(0xc00f0000, REG_W1, imm);
|
|
/* nr %w1,%dst */
|
|
EMIT2(0x1400, REG_W1, dst_reg);
|
|
} else {
|
|
/* lgfi %w1,imm (load sign extend imm) */
|
|
EMIT6_IMM(0xc0010000, REG_W1, imm);
|
|
/* ngr %w1,%dst */
|
|
EMIT4(0xb9800000, REG_W1, dst_reg);
|
|
}
|
|
goto branch_oc;
|
|
|
|
case BPF_JMP | BPF_JSGT | BPF_X: /* ((s64) dst > (s64) src) */
|
|
case BPF_JMP32 | BPF_JSGT | BPF_X: /* ((s32) dst > (s32) src) */
|
|
mask = 0x2000; /* jh */
|
|
goto branch_xs;
|
|
case BPF_JMP | BPF_JSLT | BPF_X: /* ((s64) dst < (s64) src) */
|
|
case BPF_JMP32 | BPF_JSLT | BPF_X: /* ((s32) dst < (s32) src) */
|
|
mask = 0x4000; /* jl */
|
|
goto branch_xs;
|
|
case BPF_JMP | BPF_JSGE | BPF_X: /* ((s64) dst >= (s64) src) */
|
|
case BPF_JMP32 | BPF_JSGE | BPF_X: /* ((s32) dst >= (s32) src) */
|
|
mask = 0xa000; /* jhe */
|
|
goto branch_xs;
|
|
case BPF_JMP | BPF_JSLE | BPF_X: /* ((s64) dst <= (s64) src) */
|
|
case BPF_JMP32 | BPF_JSLE | BPF_X: /* ((s32) dst <= (s32) src) */
|
|
mask = 0xc000; /* jle */
|
|
goto branch_xs;
|
|
case BPF_JMP | BPF_JGT | BPF_X: /* (dst > src) */
|
|
case BPF_JMP32 | BPF_JGT | BPF_X: /* ((u32) dst > (u32) src) */
|
|
mask = 0x2000; /* jh */
|
|
goto branch_xu;
|
|
case BPF_JMP | BPF_JLT | BPF_X: /* (dst < src) */
|
|
case BPF_JMP32 | BPF_JLT | BPF_X: /* ((u32) dst < (u32) src) */
|
|
mask = 0x4000; /* jl */
|
|
goto branch_xu;
|
|
case BPF_JMP | BPF_JGE | BPF_X: /* (dst >= src) */
|
|
case BPF_JMP32 | BPF_JGE | BPF_X: /* ((u32) dst >= (u32) src) */
|
|
mask = 0xa000; /* jhe */
|
|
goto branch_xu;
|
|
case BPF_JMP | BPF_JLE | BPF_X: /* (dst <= src) */
|
|
case BPF_JMP32 | BPF_JLE | BPF_X: /* ((u32) dst <= (u32) src) */
|
|
mask = 0xc000; /* jle */
|
|
goto branch_xu;
|
|
case BPF_JMP | BPF_JNE | BPF_X: /* (dst != src) */
|
|
case BPF_JMP32 | BPF_JNE | BPF_X: /* ((u32) dst != (u32) src) */
|
|
mask = 0x7000; /* jne */
|
|
goto branch_xu;
|
|
case BPF_JMP | BPF_JEQ | BPF_X: /* (dst == src) */
|
|
case BPF_JMP32 | BPF_JEQ | BPF_X: /* ((u32) dst == (u32) src) */
|
|
mask = 0x8000; /* je */
|
|
goto branch_xu;
|
|
case BPF_JMP | BPF_JSET | BPF_X: /* (dst & src) */
|
|
case BPF_JMP32 | BPF_JSET | BPF_X: /* ((u32) dst & (u32) src) */
|
|
{
|
|
bool is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
|
|
|
|
mask = 0x7000; /* jnz */
|
|
/* nrk or ngrk %w1,%dst,%src */
|
|
EMIT4_RRF((is_jmp32 ? 0xb9f40000 : 0xb9e40000),
|
|
REG_W1, dst_reg, src_reg);
|
|
goto branch_oc;
|
|
branch_ks:
|
|
is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
|
|
/* 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:
|
|
/* lgfi %w1,imm (load sign extend imm) */
|
|
src_reg = REG_1;
|
|
EMIT6_IMM(0xc0010000, src_reg, imm);
|
|
goto branch_xu;
|
|
branch_xs:
|
|
is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32;
|
|
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;
|
|
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:
|
|
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 */
|
|
pr_err("Unknown opcode %02x\n", insn->code);
|
|
return -1;
|
|
}
|
|
|
|
if (probe_prg != -1) {
|
|
/*
|
|
* Handlers of certain exceptions leave psw.addr pointing to
|
|
* the instruction directly after the failing one. Therefore,
|
|
* create two exception table entries and also add a nop in
|
|
* case two probing instructions come directly after each
|
|
* other.
|
|
*/
|
|
nop_prg = jit->prg;
|
|
/* bcr 0,%0 */
|
|
_EMIT2(0x0700);
|
|
err = bpf_jit_probe_mem(jit, fp, probe_prg, nop_prg);
|
|
if (err < 0)
|
|
return err;
|
|
}
|
|
|
|
return insn_count;
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
int delta;
|
|
|
|
if (is_codegen_pass(jit)) {
|
|
delta = jit->prg - jit->addrs[i];
|
|
if (delta < 0)
|
|
bpf_skip(jit, -delta);
|
|
}
|
|
if (WARN_ON_ONCE(!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, u32 stack_depth)
|
|
{
|
|
int i, insn_count, lit32_size, lit64_size;
|
|
|
|
jit->lit32 = jit->lit32_start;
|
|
jit->lit64 = jit->lit64_start;
|
|
jit->prg = 0;
|
|
jit->excnt = 0;
|
|
|
|
bpf_jit_prologue(jit, 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, stack_depth);
|
|
if (insn_count < 0)
|
|
return -1;
|
|
/* Next instruction address */
|
|
if (bpf_set_addr(jit, i + insn_count) < 0)
|
|
return -1;
|
|
}
|
|
bpf_jit_epilogue(jit, stack_depth);
|
|
|
|
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;
|
|
|
|
if (WARN_ON_ONCE(fp->aux->extable &&
|
|
jit->excnt != fp->aux->num_exentries))
|
|
/* Verifier bug - too many entries. */
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
bool bpf_jit_needs_zext(void)
|
|
{
|
|
return true;
|
|
}
|
|
|
|
struct s390_jit_data {
|
|
struct bpf_binary_header *header;
|
|
struct bpf_jit ctx;
|
|
int pass;
|
|
};
|
|
|
|
static struct bpf_binary_header *bpf_jit_alloc(struct bpf_jit *jit,
|
|
struct bpf_prog *fp)
|
|
{
|
|
struct bpf_binary_header *header;
|
|
u32 extable_size;
|
|
u32 code_size;
|
|
|
|
/* We need two entries per insn. */
|
|
fp->aux->num_exentries *= 2;
|
|
|
|
code_size = roundup(jit->size,
|
|
__alignof__(struct exception_table_entry));
|
|
extable_size = fp->aux->num_exentries *
|
|
sizeof(struct exception_table_entry);
|
|
header = bpf_jit_binary_alloc(code_size + extable_size, &jit->prg_buf,
|
|
8, jit_fill_hole);
|
|
if (!header)
|
|
return NULL;
|
|
fp->aux->extable = (struct exception_table_entry *)
|
|
(jit->prg_buf + code_size);
|
|
return header;
|
|
}
|
|
|
|
/*
|
|
* Compile eBPF program "fp"
|
|
*/
|
|
struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
|
|
{
|
|
u32 stack_depth = round_up(fp->aux->stack_depth, 8);
|
|
struct bpf_prog *tmp, *orig_fp = fp;
|
|
struct bpf_binary_header *header;
|
|
struct s390_jit_data *jit_data;
|
|
bool tmp_blinded = false;
|
|
bool extra_pass = false;
|
|
struct bpf_jit jit;
|
|
int pass;
|
|
|
|
if (!fp->jit_requested)
|
|
return orig_fp;
|
|
|
|
tmp = bpf_jit_blind_constants(fp);
|
|
/*
|
|
* If blinding was requested and we failed during blinding,
|
|
* we must fall back to the interpreter.
|
|
*/
|
|
if (IS_ERR(tmp))
|
|
return orig_fp;
|
|
if (tmp != fp) {
|
|
tmp_blinded = true;
|
|
fp = tmp;
|
|
}
|
|
|
|
jit_data = fp->aux->jit_data;
|
|
if (!jit_data) {
|
|
jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL);
|
|
if (!jit_data) {
|
|
fp = orig_fp;
|
|
goto out;
|
|
}
|
|
fp->aux->jit_data = jit_data;
|
|
}
|
|
if (jit_data->ctx.addrs) {
|
|
jit = jit_data->ctx;
|
|
header = jit_data->header;
|
|
extra_pass = true;
|
|
pass = jit_data->pass + 1;
|
|
goto skip_init_ctx;
|
|
}
|
|
|
|
memset(&jit, 0, sizeof(jit));
|
|
jit.addrs = kvcalloc(fp->len + 1, sizeof(*jit.addrs), GFP_KERNEL);
|
|
if (jit.addrs == NULL) {
|
|
fp = orig_fp;
|
|
goto out;
|
|
}
|
|
/*
|
|
* Three initial passes:
|
|
* - 1/2: Determine clobbered registers
|
|
* - 3: Calculate program size and addrs arrray
|
|
*/
|
|
for (pass = 1; pass <= 3; pass++) {
|
|
if (bpf_jit_prog(&jit, fp, extra_pass, stack_depth)) {
|
|
fp = orig_fp;
|
|
goto free_addrs;
|
|
}
|
|
}
|
|
/*
|
|
* Final pass: Allocate and generate program
|
|
*/
|
|
header = bpf_jit_alloc(&jit, fp);
|
|
if (!header) {
|
|
fp = orig_fp;
|
|
goto free_addrs;
|
|
}
|
|
skip_init_ctx:
|
|
if (bpf_jit_prog(&jit, fp, extra_pass, stack_depth)) {
|
|
bpf_jit_binary_free(header);
|
|
fp = orig_fp;
|
|
goto free_addrs;
|
|
}
|
|
if (bpf_jit_enable > 1) {
|
|
bpf_jit_dump(fp->len, jit.size, pass, jit.prg_buf);
|
|
print_fn_code(jit.prg_buf, jit.size_prg);
|
|
}
|
|
if (!fp->is_func || extra_pass) {
|
|
bpf_jit_binary_lock_ro(header);
|
|
} else {
|
|
jit_data->header = header;
|
|
jit_data->ctx = jit;
|
|
jit_data->pass = pass;
|
|
}
|
|
fp->bpf_func = (void *) jit.prg_buf;
|
|
fp->jited = 1;
|
|
fp->jited_len = jit.size;
|
|
|
|
if (!fp->is_func || extra_pass) {
|
|
bpf_prog_fill_jited_linfo(fp, jit.addrs + 1);
|
|
free_addrs:
|
|
kvfree(jit.addrs);
|
|
kfree(jit_data);
|
|
fp->aux->jit_data = NULL;
|
|
}
|
|
out:
|
|
if (tmp_blinded)
|
|
bpf_jit_prog_release_other(fp, fp == orig_fp ?
|
|
tmp : orig_fp);
|
|
return fp;
|
|
}
|