Kernel/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-01-07 13:53:24 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity
6da1cab4f5
linux/arch/powerpc/net/bpf_jit_comp64.c
Naveen N Rao d243b62b7b powerpc64/bpf: Add support for bpf trampolines 
Add support for bpf_arch_text_poke() and arch_prepare_bpf_trampoline()
for 64-bit powerpc. While the code is generic, BPF trampolines are only
enabled on 64-bit powerpc. 32-bit powerpc will need testing and some
updates.

BPF Trampolines adhere to the existing ftrace ABI utilizing a
two-instruction profiling sequence, as well as the newer ABI utilizing a
three-instruction profiling sequence enabling return with a 'blr'. The
trampoline code itself closely follows x86 implementation.

BPF prog JIT is extended to mimic 64-bit powerpc approach for ftrace
having a single nop at function entry, followed by the function
profiling sequence out-of-line and a separate long branch stub for calls
to trampolines that are out of range. A dummy_tramp is provided to
simplify synchronization similar to arm64.

When attaching a bpf trampoline to a bpf prog, we can patch up to three
things:
- the nop at bpf prog entry to go to the out-of-line stub
- the instruction in the out-of-line stub to either call the bpf trampoline
directly, or to branch to the long_branch stub.
- the trampoline address before the long_branch stub.

We do not need any synchronization here since we always have a valid
branch target regardless of the order in which the above stores are
seen. dummy_tramp ensures that the long_branch stub goes to a valid
destination on other cpus, even when the branch to the long_branch stub
is seen before the updated trampoline address.

However, when detaching a bpf trampoline from a bpf prog, or if changing
the bpf trampoline address, we need synchronization to ensure that other
cpus can no longer branch into the older trampoline so that it can be
safely freed. bpf_tramp_image_put() uses rcu_tasks to ensure all cpus
make forward progress, but we still need to ensure that other cpus
execute isync (or some CSI) so that they don't go back into the
trampoline again. While here, update the stale comment that describes
the redzone usage in ppc64 BPF JIT.

Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241030070850.1361304-18-hbathini@linux.ibm.com
2024-10-31 11:00:55 +11:00

1320 lines
39 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0-only
/*
* bpf_jit_comp64.c: eBPF JIT compiler
*
* Copyright 2016 Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
* IBM Corporation
*
* Based on the powerpc classic BPF JIT compiler by Matt Evans
*/
#include <linux/moduleloader.h>
#include <asm/cacheflush.h>
#include <asm/asm-compat.h>
#include <linux/netdevice.h>
#include <linux/filter.h>
#include <linux/if_vlan.h>
#include <asm/kprobes.h>
#include <linux/bpf.h>
#include <asm/security_features.h>
#include "bpf_jit.h"
/*
* Stack layout:
* Ensure the top half (upto local_tmp_var) stays consistent
* with our redzone usage.
*
* [ prev sp ] <-------------
* [ nv gpr save area ] 5*8 |
* [ tail_call_cnt ] 8 |
* [ local_tmp_var ] 16 |
* fp (r31) --> [ ebpf stack space ] upto 512 |
* [ frame header ] 32/112 |
* sp (r1) ---> [ stack pointer ] --------------
*/
/* for gpr non volatile registers BPG_REG_6 to 10 */
#define BPF_PPC_STACK_SAVE (5*8)
/* for bpf JIT code internal usage */
#define BPF_PPC_STACK_LOCALS 24
/* stack frame excluding BPF stack, ensure this is quadword aligned */
#define BPF_PPC_STACKFRAME (STACK_FRAME_MIN_SIZE + \
BPF_PPC_STACK_LOCALS + BPF_PPC_STACK_SAVE)
/* BPF register usage */
#define TMP_REG_1 (MAX_BPF_JIT_REG + 0)
#define TMP_REG_2 (MAX_BPF_JIT_REG + 1)
/* BPF to ppc register mappings */
void bpf_jit_init_reg_mapping(struct codegen_context *ctx)
{
/* function return value */
ctx->b2p[BPF_REG_0] = _R8;
/* function arguments */
ctx->b2p[BPF_REG_1] = _R3;
ctx->b2p[BPF_REG_2] = _R4;
ctx->b2p[BPF_REG_3] = _R5;
ctx->b2p[BPF_REG_4] = _R6;
ctx->b2p[BPF_REG_5] = _R7;
/* non volatile registers */
ctx->b2p[BPF_REG_6] = _R27;
ctx->b2p[BPF_REG_7] = _R28;
ctx->b2p[BPF_REG_8] = _R29;
ctx->b2p[BPF_REG_9] = _R30;
/* frame pointer aka BPF_REG_10 */
ctx->b2p[BPF_REG_FP] = _R31;
/* eBPF jit internal registers */
ctx->b2p[BPF_REG_AX] = _R12;
ctx->b2p[TMP_REG_1] = _R9;
ctx->b2p[TMP_REG_2] = _R10;
}
/* PPC NVR range -- update this if we ever use NVRs below r27 */
#define BPF_PPC_NVR_MIN _R27
static inline bool bpf_has_stack_frame(struct codegen_context *ctx)
{
/*
* We only need a stack frame if:
* - we call other functions (kernel helpers), or
* - the bpf program uses its stack area
* The latter condition is deduced from the usage of BPF_REG_FP
*/
return ctx->seen & SEEN_FUNC || bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP));
}
/*
* When not setting up our own stackframe, the redzone (288 bytes) usage is:
*
* [ prev sp ] <-------------
* [ ... ] |
* sp (r1) ---> [ stack pointer ] --------------
* [ nv gpr save area ] 5*8
* [ tail_call_cnt ] 8
* [ local_tmp_var ] 16
* [ unused red zone ] 224
*/
static int bpf_jit_stack_local(struct codegen_context *ctx)
{
if (bpf_has_stack_frame(ctx))
return STACK_FRAME_MIN_SIZE + ctx->stack_size;
else
return -(BPF_PPC_STACK_SAVE + 24);
}
static int bpf_jit_stack_tailcallcnt(struct codegen_context *ctx)
{
return bpf_jit_stack_local(ctx) + 16;
}
static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg)
{
if (reg >= BPF_PPC_NVR_MIN && reg < 32)
return (bpf_has_stack_frame(ctx) ?
(BPF_PPC_STACKFRAME + ctx->stack_size) : 0)
- (8 * (32 - reg));
pr_err("BPF JIT is asking about unknown registers");
BUG();
}
void bpf_jit_realloc_regs(struct codegen_context *ctx)
{
}
void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
{
int i;
/* Instruction for trampoline attach */
EMIT(PPC_RAW_NOP());
#ifndef CONFIG_PPC_KERNEL_PCREL
if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
EMIT(PPC_RAW_LD(_R2, _R13, offsetof(struct paca_struct, kernel_toc)));
#endif
/*
* Initialize tail_call_cnt if we do tail calls.
* Otherwise, put in NOPs so that it can be skipped when we are
* invoked through a tail call.
*/
if (ctx->seen & SEEN_TAILCALL) {
EMIT(PPC_RAW_LI(bpf_to_ppc(TMP_REG_1), 0));
/* this goes in the redzone */
EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, -(BPF_PPC_STACK_SAVE + 8)));
} else {
EMIT(PPC_RAW_NOP());
EMIT(PPC_RAW_NOP());
}
if (bpf_has_stack_frame(ctx)) {
/*
* We need a stack frame, but we don't necessarily need to
* save/restore LR unless we call other functions
*/
if (ctx->seen & SEEN_FUNC) {
EMIT(PPC_RAW_MFLR(_R0));
EMIT(PPC_RAW_STD(_R0, _R1, PPC_LR_STKOFF));
}
EMIT(PPC_RAW_STDU(_R1, _R1, -(BPF_PPC_STACKFRAME + ctx->stack_size)));
}
/*
* Back up non-volatile regs -- BPF registers 6-10
* If we haven't created our own stack frame, we save these
* in the protected zone below the previous stack frame
*/
for (i = BPF_REG_6; i <= BPF_REG_10; i++)
if (bpf_is_seen_register(ctx, bpf_to_ppc(i)))
EMIT(PPC_RAW_STD(bpf_to_ppc(i), _R1, bpf_jit_stack_offsetof(ctx, bpf_to_ppc(i))));
/* Setup frame pointer to point to the bpf stack area */
if (bpf_is_seen_register(ctx, bpf_to_ppc(BPF_REG_FP)))
EMIT(PPC_RAW_ADDI(bpf_to_ppc(BPF_REG_FP), _R1,
STACK_FRAME_MIN_SIZE + ctx->stack_size));
}
static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx)
{
int i;
/* Restore NVRs */
for (i = BPF_REG_6; i <= BPF_REG_10; i++)
if (bpf_is_seen_register(ctx, bpf_to_ppc(i)))
EMIT(PPC_RAW_LD(bpf_to_ppc(i), _R1, bpf_jit_stack_offsetof(ctx, bpf_to_ppc(i))));
/* Tear down our stack frame */
if (bpf_has_stack_frame(ctx)) {
EMIT(PPC_RAW_ADDI(_R1, _R1, BPF_PPC_STACKFRAME + ctx->stack_size));
if (ctx->seen & SEEN_FUNC) {
EMIT(PPC_RAW_LD(_R0, _R1, PPC_LR_STKOFF));
EMIT(PPC_RAW_MTLR(_R0));
}
}
}
void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx)
{
bpf_jit_emit_common_epilogue(image, ctx);
/* Move result to r3 */
EMIT(PPC_RAW_MR(_R3, bpf_to_ppc(BPF_REG_0)));
EMIT(PPC_RAW_BLR());
bpf_jit_build_fentry_stubs(image, ctx);
}
int bpf_jit_emit_func_call_rel(u32 *image, u32 *fimage, struct codegen_context *ctx, u64 func)
{
unsigned long func_addr = func ? ppc_function_entry((void *)func) : 0;
long reladdr;
/* bpf to bpf call, func is not known in the initial pass. Emit 5 nops as a placeholder */
if (!func) {
for (int i = 0; i < 5; i++)
EMIT(PPC_RAW_NOP());
/* elfv1 needs an additional instruction to load addr from descriptor */
if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1))
EMIT(PPC_RAW_NOP());
EMIT(PPC_RAW_MTCTR(_R12));
EMIT(PPC_RAW_BCTRL());
return 0;
}
#ifdef CONFIG_PPC_KERNEL_PCREL
reladdr = func_addr - local_paca->kernelbase;
if (reladdr < (long)SZ_8G && reladdr >= -(long)SZ_8G) {
EMIT(PPC_RAW_LD(_R12, _R13, offsetof(struct paca_struct, kernelbase)));
/* Align for subsequent prefix instruction */
if (!IS_ALIGNED((unsigned long)fimage + CTX_NIA(ctx), 8))
EMIT(PPC_RAW_NOP());
/* paddi r12,r12,addr */
EMIT(PPC_PREFIX_MLS | __PPC_PRFX_R(0) | IMM_H18(reladdr));
EMIT(PPC_INST_PADDI | ___PPC_RT(_R12) | ___PPC_RA(_R12) | IMM_L(reladdr));
} else {
unsigned long pc = (unsigned long)fimage + CTX_NIA(ctx);
bool alignment_needed = !IS_ALIGNED(pc, 8);
reladdr = func_addr - (alignment_needed ? pc + 4 : pc);
if (reladdr < (long)SZ_8G && reladdr >= -(long)SZ_8G) {
if (alignment_needed)
EMIT(PPC_RAW_NOP());
/* pla r12,addr */
EMIT(PPC_PREFIX_MLS | __PPC_PRFX_R(1) | IMM_H18(reladdr));
EMIT(PPC_INST_PADDI | ___PPC_RT(_R12) | IMM_L(reladdr));
} else {
/* We can clobber r12 */
PPC_LI64(_R12, func);
}
}
EMIT(PPC_RAW_MTCTR(_R12));
EMIT(PPC_RAW_BCTRL());
#else
if (core_kernel_text(func_addr)) {
reladdr = func_addr - kernel_toc_addr();
if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) {
pr_err("eBPF: address of %ps out of range of kernel_toc.\n", (void *)func);
return -ERANGE;
}
EMIT(PPC_RAW_ADDIS(_R12, _R2, PPC_HA(reladdr)));
EMIT(PPC_RAW_ADDI(_R12, _R12, PPC_LO(reladdr)));
EMIT(PPC_RAW_MTCTR(_R12));
EMIT(PPC_RAW_BCTRL());
} else {
if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1)) {
/* func points to the function descriptor */
PPC_LI64(bpf_to_ppc(TMP_REG_2), func);
/* Load actual entry point from function descriptor */
EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_2), 0));
/* ... and move it to CTR */
EMIT(PPC_RAW_MTCTR(bpf_to_ppc(TMP_REG_1)));
/*
* Load TOC from function descriptor at offset 8.
* We can clobber r2 since we get called through a
* function pointer (so caller will save/restore r2).
*/
if (is_module_text_address(func_addr))
EMIT(PPC_RAW_LD(_R2, bpf_to_ppc(TMP_REG_2), 8));
} else {
PPC_LI64(_R12, func);
EMIT(PPC_RAW_MTCTR(_R12));
}
EMIT(PPC_RAW_BCTRL());
/*
* Load r2 with kernel TOC as kernel TOC is used if function address falls
* within core kernel text.
*/
if (is_module_text_address(func_addr))
EMIT(PPC_RAW_LD(_R2, _R13, offsetof(struct paca_struct, kernel_toc)));
}
#endif
return 0;
}
static int bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32 out)
{
/*
* By now, the eBPF program has already setup parameters in r3, r4 and r5
* r3/BPF_REG_1 - pointer to ctx -- passed as is to the next bpf program
* r4/BPF_REG_2 - pointer to bpf_array
* r5/BPF_REG_3 - index in bpf_array
*/
int b2p_bpf_array = bpf_to_ppc(BPF_REG_2);
int b2p_index = bpf_to_ppc(BPF_REG_3);
int bpf_tailcall_prologue_size = 12;
if (!IS_ENABLED(CONFIG_PPC_KERNEL_PCREL) && IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2))
bpf_tailcall_prologue_size += 4; /* skip past the toc load */
/*
* if (index >= array->map.max_entries)
* goto out;
*/
EMIT(PPC_RAW_LWZ(bpf_to_ppc(TMP_REG_1), b2p_bpf_array, offsetof(struct bpf_array, map.max_entries)));
EMIT(PPC_RAW_RLWINM(b2p_index, b2p_index, 0, 0, 31));
EMIT(PPC_RAW_CMPLW(b2p_index, bpf_to_ppc(TMP_REG_1)));
PPC_BCC_SHORT(COND_GE, out);
/*
* if (tail_call_cnt >= MAX_TAIL_CALL_CNT)
* goto out;
*/
EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), _R1, bpf_jit_stack_tailcallcnt(ctx)));
EMIT(PPC_RAW_CMPLWI(bpf_to_ppc(TMP_REG_1), MAX_TAIL_CALL_CNT));
PPC_BCC_SHORT(COND_GE, out);
/*
* tail_call_cnt++;
*/
EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), 1));
EMIT(PPC_RAW_STD(bpf_to_ppc(TMP_REG_1), _R1, bpf_jit_stack_tailcallcnt(ctx)));
/* prog = array->ptrs[index]; */
EMIT(PPC_RAW_MULI(bpf_to_ppc(TMP_REG_1), b2p_index, 8));
EMIT(PPC_RAW_ADD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), b2p_bpf_array));
EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), offsetof(struct bpf_array, ptrs)));
/*
* if (prog == NULL)
* goto out;
*/
EMIT(PPC_RAW_CMPLDI(bpf_to_ppc(TMP_REG_1), 0));
PPC_BCC_SHORT(COND_EQ, out);
/* goto *(prog->bpf_func + prologue_size); */
EMIT(PPC_RAW_LD(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1), offsetof(struct bpf_prog, bpf_func)));
EMIT(PPC_RAW_ADDI(bpf_to_ppc(TMP_REG_1), bpf_to_ppc(TMP_REG_1),
FUNCTION_DESCR_SIZE + bpf_tailcall_prologue_size));
EMIT(PPC_RAW_MTCTR(bpf_to_ppc(TMP_REG_1)));
/* tear down stack, restore NVRs, ... */
bpf_jit_emit_common_epilogue(image, ctx);
EMIT(PPC_RAW_BCTR());
/* out: */
return 0;
}
/*
* We spill into the redzone always, even if the bpf program has its own stackframe.
* Offsets hardcoded based on BPF_PPC_STACK_SAVE -- see bpf_jit_stack_local()
*/
void bpf_stf_barrier(void);
asm (
" .global bpf_stf_barrier ;"
" bpf_stf_barrier: ;"
" std 21,-64(1) ;"
" std 22,-56(1) ;"
" sync ;"
" ld 21,-64(1) ;"
" ld 22,-56(1) ;"
" ori 31,31,0 ;"
" .rept 14 ;"
" b 1f ;"
" 1: ;"
" .endr ;"
" blr ;"
);
/* Assemble the body code between the prologue & epilogue */
int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, u32 *fimage, struct codegen_context *ctx,
u32 *addrs, int pass, bool extra_pass)
{
enum stf_barrier_type stf_barrier = stf_barrier_type_get();
const struct bpf_insn *insn = fp->insnsi;
int flen = fp->len;
int i, ret;
/* Start of epilogue code - will only be valid 2nd pass onwards */
u32 exit_addr = addrs[flen];
for (i = 0; i < flen; i++) {
u32 code = insn[i].code;
u32 dst_reg = bpf_to_ppc(insn[i].dst_reg);
u32 src_reg = bpf_to_ppc(insn[i].src_reg);
u32 size = BPF_SIZE(code);
u32 tmp1_reg = bpf_to_ppc(TMP_REG_1);
u32 tmp2_reg = bpf_to_ppc(TMP_REG_2);
u32 save_reg, ret_reg;
s16 off = insn[i].off;
s32 imm = insn[i].imm;
bool func_addr_fixed;
u64 func_addr;
u64 imm64;
u32 true_cond;
u32 tmp_idx;
int j;
/*
* addrs[] maps a BPF bytecode address into a real offset from
* the start of the body code.
*/
addrs[i] = ctx->idx * 4;
/*
* As an optimization, we note down which non-volatile registers
* are used so that we can only save/restore those in our
* prologue and epilogue. We do this here regardless of whether
* the actual BPF instruction uses src/dst registers or not
* (for instance, BPF_CALL does not use them). The expectation
* is that those instructions will have src_reg/dst_reg set to
* 0. Even otherwise, we just lose some prologue/epilogue
* optimization but everything else should work without
* any issues.
*/
if (dst_reg >= BPF_PPC_NVR_MIN && dst_reg < 32)
bpf_set_seen_register(ctx, dst_reg);
if (src_reg >= BPF_PPC_NVR_MIN && src_reg < 32)
bpf_set_seen_register(ctx, src_reg);
switch (code) {
/*
* Arithmetic operations: ADD/SUB/MUL/DIV/MOD/NEG
*/
case BPF_ALU | BPF_ADD | BPF_X: /* (u32) dst += (u32) src */
case BPF_ALU64 | BPF_ADD | BPF_X: /* dst += src */
EMIT(PPC_RAW_ADD(dst_reg, dst_reg, src_reg));
goto bpf_alu32_trunc;
case BPF_ALU | BPF_SUB | BPF_X: /* (u32) dst -= (u32) src */
case BPF_ALU64 | BPF_SUB | BPF_X: /* dst -= src */
EMIT(PPC_RAW_SUB(dst_reg, dst_reg, src_reg));
goto bpf_alu32_trunc;
case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */
case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */
if (!imm) {
goto bpf_alu32_trunc;
} else if (imm >= -32768 && imm < 32768) {
EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(imm)));
} else {
PPC_LI32(tmp1_reg, imm);
EMIT(PPC_RAW_ADD(dst_reg, dst_reg, tmp1_reg));
}
goto bpf_alu32_trunc;
case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */
case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */
if (!imm) {
goto bpf_alu32_trunc;
} else if (imm > -32768 && imm <= 32768) {
EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(-imm)));
} else {
PPC_LI32(tmp1_reg, imm);
EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
}
goto bpf_alu32_trunc;
case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */
case BPF_ALU64 | BPF_MUL | BPF_X: /* dst *= src */
if (BPF_CLASS(code) == BPF_ALU)
EMIT(PPC_RAW_MULW(dst_reg, dst_reg, src_reg));
else
EMIT(PPC_RAW_MULD(dst_reg, dst_reg, src_reg));
goto bpf_alu32_trunc;
case BPF_ALU | BPF_MUL | BPF_K: /* (u32) dst *= (u32) imm */
case BPF_ALU64 | BPF_MUL | BPF_K: /* dst *= imm */
if (imm >= -32768 && imm < 32768)
EMIT(PPC_RAW_MULI(dst_reg, dst_reg, IMM_L(imm)));
else {
PPC_LI32(tmp1_reg, imm);
if (BPF_CLASS(code) == BPF_ALU)
EMIT(PPC_RAW_MULW(dst_reg, dst_reg, tmp1_reg));
else
EMIT(PPC_RAW_MULD(dst_reg, dst_reg, tmp1_reg));
}
goto bpf_alu32_trunc;
case BPF_ALU | BPF_DIV | BPF_X: /* (u32) dst /= (u32) src */
case BPF_ALU | BPF_MOD | BPF_X: /* (u32) dst %= (u32) src */
if (BPF_OP(code) == BPF_MOD) {
if (off)
EMIT(PPC_RAW_DIVW(tmp1_reg, dst_reg, src_reg));
else
EMIT(PPC_RAW_DIVWU(tmp1_reg, dst_reg, src_reg));
EMIT(PPC_RAW_MULW(tmp1_reg, src_reg, tmp1_reg));
EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
} else
if (off)
EMIT(PPC_RAW_DIVW(dst_reg, dst_reg, src_reg));
else
EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, src_reg));
goto bpf_alu32_trunc;
case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */
case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */
if (BPF_OP(code) == BPF_MOD) {
if (off)
EMIT(PPC_RAW_DIVD(tmp1_reg, dst_reg, src_reg));
else
EMIT(PPC_RAW_DIVDU(tmp1_reg, dst_reg, src_reg));
EMIT(PPC_RAW_MULD(tmp1_reg, src_reg, tmp1_reg));
EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
} else
if (off)
EMIT(PPC_RAW_DIVD(dst_reg, dst_reg, src_reg));
else
EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, src_reg));
break;
case BPF_ALU | BPF_MOD | BPF_K: /* (u32) dst %= (u32) imm */
case BPF_ALU | BPF_DIV | BPF_K: /* (u32) dst /= (u32) imm */
case BPF_ALU64 | BPF_MOD | BPF_K: /* dst %= imm */
case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */
if (imm == 0)
return -EINVAL;
if (imm == 1) {
if (BPF_OP(code) == BPF_DIV) {
goto bpf_alu32_trunc;
} else {
EMIT(PPC_RAW_LI(dst_reg, 0));
break;
}
}
PPC_LI32(tmp1_reg, imm);
switch (BPF_CLASS(code)) {
case BPF_ALU:
if (BPF_OP(code) == BPF_MOD) {
if (off)
EMIT(PPC_RAW_DIVW(tmp2_reg, dst_reg, tmp1_reg));
else
EMIT(PPC_RAW_DIVWU(tmp2_reg, dst_reg, tmp1_reg));
EMIT(PPC_RAW_MULW(tmp1_reg, tmp1_reg, tmp2_reg));
EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
} else
if (off)
EMIT(PPC_RAW_DIVW(dst_reg, dst_reg, tmp1_reg));
else
EMIT(PPC_RAW_DIVWU(dst_reg, dst_reg, tmp1_reg));
break;
case BPF_ALU64:
if (BPF_OP(code) == BPF_MOD) {
if (off)
EMIT(PPC_RAW_DIVD(tmp2_reg, dst_reg, tmp1_reg));
else
EMIT(PPC_RAW_DIVDU(tmp2_reg, dst_reg, tmp1_reg));
EMIT(PPC_RAW_MULD(tmp1_reg, tmp1_reg, tmp2_reg));
EMIT(PPC_RAW_SUB(dst_reg, dst_reg, tmp1_reg));
} else
if (off)
EMIT(PPC_RAW_DIVD(dst_reg, dst_reg, tmp1_reg));
else
EMIT(PPC_RAW_DIVDU(dst_reg, dst_reg, tmp1_reg));
break;
}
goto bpf_alu32_trunc;
case BPF_ALU | BPF_NEG: /* (u32) dst = -dst */
case BPF_ALU64 | BPF_NEG: /* dst = -dst */
EMIT(PPC_RAW_NEG(dst_reg, dst_reg));
goto bpf_alu32_trunc;
/*
* Logical operations: AND/OR/XOR/[A]LSH/[A]RSH
*/
case BPF_ALU | BPF_AND | BPF_X: /* (u32) dst = dst & src */
case BPF_ALU64 | BPF_AND | BPF_X: /* dst = dst & src */
EMIT(PPC_RAW_AND(dst_reg, dst_reg, src_reg));
goto bpf_alu32_trunc;
case BPF_ALU | BPF_AND | BPF_K: /* (u32) dst = dst & imm */
case BPF_ALU64 | BPF_AND | BPF_K: /* dst = dst & imm */
if (!IMM_H(imm))
EMIT(PPC_RAW_ANDI(dst_reg, dst_reg, IMM_L(imm)));
else {
/* Sign-extended */
PPC_LI32(tmp1_reg, imm);
EMIT(PPC_RAW_AND(dst_reg, dst_reg, tmp1_reg));
}
goto bpf_alu32_trunc;
case BPF_ALU | BPF_OR | BPF_X: /* dst = (u32) dst | (u32) src */
case BPF_ALU64 | BPF_OR | BPF_X: /* dst = dst | src */
EMIT(PPC_RAW_OR(dst_reg, dst_reg, src_reg));
goto bpf_alu32_trunc;
case BPF_ALU | BPF_OR | BPF_K:/* dst = (u32) dst | (u32) imm */
case BPF_ALU64 | BPF_OR | BPF_K:/* dst = dst | imm */
if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) {
/* Sign-extended */
PPC_LI32(tmp1_reg, imm);
EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp1_reg));
} else {
if (IMM_L(imm))
EMIT(PPC_RAW_ORI(dst_reg, dst_reg, IMM_L(imm)));
if (IMM_H(imm))
EMIT(PPC_RAW_ORIS(dst_reg, dst_reg, IMM_H(imm)));
}
goto bpf_alu32_trunc;
case BPF_ALU | BPF_XOR | BPF_X: /* (u32) dst ^= src */
case BPF_ALU64 | BPF_XOR | BPF_X: /* dst ^= src */
EMIT(PPC_RAW_XOR(dst_reg, dst_reg, src_reg));
goto bpf_alu32_trunc;
case BPF_ALU | BPF_XOR | BPF_K: /* (u32) dst ^= (u32) imm */
case BPF_ALU64 | BPF_XOR | BPF_K: /* dst ^= imm */
if (imm < 0 && BPF_CLASS(code) == BPF_ALU64) {
/* Sign-extended */
PPC_LI32(tmp1_reg, imm);
EMIT(PPC_RAW_XOR(dst_reg, dst_reg, tmp1_reg));
} else {
if (IMM_L(imm))
EMIT(PPC_RAW_XORI(dst_reg, dst_reg, IMM_L(imm)));
if (IMM_H(imm))
EMIT(PPC_RAW_XORIS(dst_reg, dst_reg, IMM_H(imm)));
}
goto bpf_alu32_trunc;
case BPF_ALU | BPF_LSH | BPF_X: /* (u32) dst <<= (u32) src */
/* slw clears top 32 bits */
EMIT(PPC_RAW_SLW(dst_reg, dst_reg, src_reg));
/* skip zero extension move, but set address map. */
if (insn_is_zext(&insn[i + 1]))
addrs[++i] = ctx->idx * 4;
break;
case BPF_ALU64 | BPF_LSH | BPF_X: /* dst <<= src; */
EMIT(PPC_RAW_SLD(dst_reg, dst_reg, src_reg));
break;
case BPF_ALU | BPF_LSH | BPF_K: /* (u32) dst <<== (u32) imm */
/* with imm 0, we still need to clear top 32 bits */
EMIT(PPC_RAW_SLWI(dst_reg, dst_reg, imm));
if (insn_is_zext(&insn[i + 1]))
addrs[++i] = ctx->idx * 4;
break;
case BPF_ALU64 | BPF_LSH | BPF_K: /* dst <<== imm */
if (imm != 0)
EMIT(PPC_RAW_SLDI(dst_reg, dst_reg, imm));
break;
case BPF_ALU | BPF_RSH | BPF_X: /* (u32) dst >>= (u32) src */
EMIT(PPC_RAW_SRW(dst_reg, dst_reg, src_reg));
if (insn_is_zext(&insn[i + 1]))
addrs[++i] = ctx->idx * 4;
break;
case BPF_ALU64 | BPF_RSH | BPF_X: /* dst >>= src */
EMIT(PPC_RAW_SRD(dst_reg, dst_reg, src_reg));
break;
case BPF_ALU | BPF_RSH | BPF_K: /* (u32) dst >>= (u32) imm */
EMIT(PPC_RAW_SRWI(dst_reg, dst_reg, imm));
if (insn_is_zext(&insn[i + 1]))
addrs[++i] = ctx->idx * 4;
break;
case BPF_ALU64 | BPF_RSH | BPF_K: /* dst >>= imm */
if (imm != 0)
EMIT(PPC_RAW_SRDI(dst_reg, dst_reg, imm));
break;
case BPF_ALU | BPF_ARSH | BPF_X: /* (s32) dst >>= src */
EMIT(PPC_RAW_SRAW(dst_reg, dst_reg, src_reg));
goto bpf_alu32_trunc;
case BPF_ALU64 | BPF_ARSH | BPF_X: /* (s64) dst >>= src */
EMIT(PPC_RAW_SRAD(dst_reg, dst_reg, src_reg));
break;
case BPF_ALU | BPF_ARSH | BPF_K: /* (s32) dst >>= imm */
EMIT(PPC_RAW_SRAWI(dst_reg, dst_reg, imm));
goto bpf_alu32_trunc;
case BPF_ALU64 | BPF_ARSH | BPF_K: /* (s64) dst >>= imm */
if (imm != 0)
EMIT(PPC_RAW_SRADI(dst_reg, dst_reg, imm));
break;
/*
* MOV
*/
case BPF_ALU | BPF_MOV | BPF_X: /* (u32) dst = src */
case BPF_ALU64 | BPF_MOV | BPF_X: /* dst = src */
if (imm == 1) {
/* special mov32 for zext */
EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 0, 31));
break;
} else if (off == 8) {
EMIT(PPC_RAW_EXTSB(dst_reg, src_reg));
} else if (off == 16) {
EMIT(PPC_RAW_EXTSH(dst_reg, src_reg));
} else if (off == 32) {
EMIT(PPC_RAW_EXTSW(dst_reg, src_reg));
} else if (dst_reg != src_reg)
EMIT(PPC_RAW_MR(dst_reg, src_reg));
goto bpf_alu32_trunc;
case BPF_ALU | BPF_MOV | BPF_K: /* (u32) dst = imm */
case BPF_ALU64 | BPF_MOV | BPF_K: /* dst = (s64) imm */
PPC_LI32(dst_reg, imm);
if (imm < 0)
goto bpf_alu32_trunc;
else if (insn_is_zext(&insn[i + 1]))
addrs[++i] = ctx->idx * 4;
break;
bpf_alu32_trunc:
/* Truncate to 32-bits */
if (BPF_CLASS(code) == BPF_ALU && !fp->aux->verifier_zext)
EMIT(PPC_RAW_RLWINM(dst_reg, dst_reg, 0, 0, 31));
break;
/*
* BPF_FROM_BE/LE
*/
case BPF_ALU | BPF_END | BPF_FROM_LE:
case BPF_ALU | BPF_END | BPF_FROM_BE:
case BPF_ALU64 | BPF_END | BPF_FROM_LE:
#ifdef __BIG_ENDIAN__
if (BPF_SRC(code) == BPF_FROM_BE)
goto emit_clear;
#else /* !__BIG_ENDIAN__ */
if (BPF_CLASS(code) == BPF_ALU && BPF_SRC(code) == BPF_FROM_LE)
goto emit_clear;
#endif
switch (imm) {
case 16:
/* Rotate 8 bits left & mask with 0x0000ff00 */
EMIT(PPC_RAW_RLWINM(tmp1_reg, dst_reg, 8, 16, 23));
/* Rotate 8 bits right & insert LSB to reg */
EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 24, 31));
/* Move result back to dst_reg */
EMIT(PPC_RAW_MR(dst_reg, tmp1_reg));
break;
case 32:
/*
* Rotate word left by 8 bits:
* 2 bytes are already in their final position
* -- byte 2 and 4 (of bytes 1, 2, 3 and 4)
*/
EMIT(PPC_RAW_RLWINM(tmp1_reg, dst_reg, 8, 0, 31));
/* Rotate 24 bits and insert byte 1 */
EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 0, 7));
/* Rotate 24 bits and insert byte 3 */
EMIT(PPC_RAW_RLWIMI(tmp1_reg, dst_reg, 24, 16, 23));
EMIT(PPC_RAW_MR(dst_reg, tmp1_reg));
break;
case 64:
/* Store the value to stack and then use byte-reverse loads */
EMIT(PPC_RAW_STD(dst_reg, _R1, bpf_jit_stack_local(ctx)));
EMIT(PPC_RAW_ADDI(tmp1_reg, _R1, bpf_jit_stack_local(ctx)));
if (cpu_has_feature(CPU_FTR_ARCH_206)) {
EMIT(PPC_RAW_LDBRX(dst_reg, 0, tmp1_reg));
} else {
EMIT(PPC_RAW_LWBRX(dst_reg, 0, tmp1_reg));
if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN))
EMIT(PPC_RAW_SLDI(dst_reg, dst_reg, 32));
EMIT(PPC_RAW_LI(tmp2_reg, 4));
EMIT(PPC_RAW_LWBRX(tmp2_reg, tmp2_reg, tmp1_reg));
if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
EMIT(PPC_RAW_SLDI(tmp2_reg, tmp2_reg, 32));
EMIT(PPC_RAW_OR(dst_reg, dst_reg, tmp2_reg));
}
break;
}
break;
emit_clear:
switch (imm) {
case 16:
/* zero-extend 16 bits into 64 bits */
EMIT(PPC_RAW_RLDICL(dst_reg, dst_reg, 0, 48));
if (insn_is_zext(&insn[i + 1]))
addrs[++i] = ctx->idx * 4;
break;
case 32:
if (!fp->aux->verifier_zext)
/* zero-extend 32 bits into 64 bits */
EMIT(PPC_RAW_RLDICL(dst_reg, dst_reg, 0, 32));
break;
case 64:
/* nop */
break;
}
break;
/*
* BPF_ST NOSPEC (speculation barrier)
*/
case BPF_ST | BPF_NOSPEC:
if (!security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) ||
!security_ftr_enabled(SEC_FTR_STF_BARRIER))
break;
switch (stf_barrier) {
case STF_BARRIER_EIEIO:
EMIT(PPC_RAW_EIEIO() | 0x02000000);
break;
case STF_BARRIER_SYNC_ORI:
EMIT(PPC_RAW_SYNC());
EMIT(PPC_RAW_LD(tmp1_reg, _R13, 0));
EMIT(PPC_RAW_ORI(_R31, _R31, 0));
break;
case STF_BARRIER_FALLBACK:
ctx->seen |= SEEN_FUNC;
PPC_LI64(_R12, dereference_kernel_function_descriptor(bpf_stf_barrier));
EMIT(PPC_RAW_MTCTR(_R12));
EMIT(PPC_RAW_BCTRL());
break;
case STF_BARRIER_NONE:
break;
}
break;
/*
* BPF_ST(X)
*/
case BPF_STX | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = src */
case BPF_ST | BPF_MEM | BPF_B: /* *(u8 *)(dst + off) = imm */
if (BPF_CLASS(code) == BPF_ST) {
EMIT(PPC_RAW_LI(tmp1_reg, imm));
src_reg = tmp1_reg;
}
EMIT(PPC_RAW_STB(src_reg, dst_reg, off));
break;
case BPF_STX | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = src */
case BPF_ST | BPF_MEM | BPF_H: /* (u16 *)(dst + off) = imm */
if (BPF_CLASS(code) == BPF_ST) {
EMIT(PPC_RAW_LI(tmp1_reg, imm));
src_reg = tmp1_reg;
}
EMIT(PPC_RAW_STH(src_reg, dst_reg, off));
break;
case BPF_STX | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = src */
case BPF_ST | BPF_MEM | BPF_W: /* *(u32 *)(dst + off) = imm */
if (BPF_CLASS(code) == BPF_ST) {
PPC_LI32(tmp1_reg, imm);
src_reg = tmp1_reg;
}
EMIT(PPC_RAW_STW(src_reg, dst_reg, off));
break;
case BPF_STX | BPF_MEM | BPF_DW: /* (u64 *)(dst + off) = src */
case BPF_ST | BPF_MEM | BPF_DW: /* *(u64 *)(dst + off) = imm */
if (BPF_CLASS(code) == BPF_ST) {
PPC_LI32(tmp1_reg, imm);
src_reg = tmp1_reg;
}
if (off % 4) {
EMIT(PPC_RAW_LI(tmp2_reg, off));
EMIT(PPC_RAW_STDX(src_reg, dst_reg, tmp2_reg));
} else {
EMIT(PPC_RAW_STD(src_reg, dst_reg, off));
}
break;
/*
* BPF_STX ATOMIC (atomic ops)
*/
case BPF_STX | BPF_ATOMIC | BPF_W:
case BPF_STX | BPF_ATOMIC | BPF_DW:
save_reg = tmp2_reg;
ret_reg = src_reg;
/* Get offset into TMP_REG_1 */
EMIT(PPC_RAW_LI(tmp1_reg, off));
/*
* Enforce full ordering for operations with BPF_FETCH by emitting a 'sync'
* before and after the operation.
*
* This is a requirement in the Linux Kernel Memory Model.
* See __cmpxchg_u64() in asm/cmpxchg.h as an example.
*/
if ((imm & BPF_FETCH) && IS_ENABLED(CONFIG_SMP))
EMIT(PPC_RAW_SYNC());
tmp_idx = ctx->idx * 4;
/* load value from memory into TMP_REG_2 */
if (size == BPF_DW)
EMIT(PPC_RAW_LDARX(tmp2_reg, tmp1_reg, dst_reg, 0));
else
EMIT(PPC_RAW_LWARX(tmp2_reg, tmp1_reg, dst_reg, 0));
/* Save old value in _R0 */
if (imm & BPF_FETCH)
EMIT(PPC_RAW_MR(_R0, tmp2_reg));
switch (imm) {
case BPF_ADD:
case BPF_ADD | BPF_FETCH:
EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg));
break;
case BPF_AND:
case BPF_AND | BPF_FETCH:
EMIT(PPC_RAW_AND(tmp2_reg, tmp2_reg, src_reg));
break;
case BPF_OR:
case BPF_OR | BPF_FETCH:
EMIT(PPC_RAW_OR(tmp2_reg, tmp2_reg, src_reg));
break;
case BPF_XOR:
case BPF_XOR | BPF_FETCH:
EMIT(PPC_RAW_XOR(tmp2_reg, tmp2_reg, src_reg));
break;
case BPF_CMPXCHG:
/*
* Return old value in BPF_REG_0 for BPF_CMPXCHG &
* in src_reg for other cases.
*/
ret_reg = bpf_to_ppc(BPF_REG_0);
/* Compare with old value in BPF_R0 */
if (size == BPF_DW)
EMIT(PPC_RAW_CMPD(bpf_to_ppc(BPF_REG_0), tmp2_reg));
else
EMIT(PPC_RAW_CMPW(bpf_to_ppc(BPF_REG_0), tmp2_reg));
/* Don't set if different from old value */
PPC_BCC_SHORT(COND_NE, (ctx->idx + 3) * 4);
fallthrough;
case BPF_XCHG:
save_reg = src_reg;
break;
default:
pr_err_ratelimited(
"eBPF filter atomic op code %02x (@%d) unsupported\n",
code, i);
return -EOPNOTSUPP;
}
/* store new value */
if (size == BPF_DW)
EMIT(PPC_RAW_STDCX(save_reg, tmp1_reg, dst_reg));
else
EMIT(PPC_RAW_STWCX(save_reg, tmp1_reg, dst_reg));
/* we're done if this succeeded */
PPC_BCC_SHORT(COND_NE, tmp_idx);
if (imm & BPF_FETCH) {
/* Emit 'sync' to enforce full ordering */
if (IS_ENABLED(CONFIG_SMP))
EMIT(PPC_RAW_SYNC());
EMIT(PPC_RAW_MR(ret_reg, _R0));
/*
* Skip unnecessary zero-extension for 32-bit cmpxchg.
* For context, see commit 39491867ace5.
*/
if (size != BPF_DW && imm == BPF_CMPXCHG &&
insn_is_zext(&insn[i + 1]))
addrs[++i] = ctx->idx * 4;
}
break;
/*
* BPF_LDX
*/
/* dst = *(u8 *)(ul) (src + off) */
case BPF_LDX | BPF_MEM | BPF_B:
case BPF_LDX | BPF_MEMSX | BPF_B:
case BPF_LDX | BPF_PROBE_MEM | BPF_B:
case BPF_LDX | BPF_PROBE_MEMSX | BPF_B:
/* dst = *(u16 *)(ul) (src + off) */
case BPF_LDX | BPF_MEM | BPF_H:
case BPF_LDX | BPF_MEMSX | BPF_H:
case BPF_LDX | BPF_PROBE_MEM | BPF_H:
case BPF_LDX | BPF_PROBE_MEMSX | BPF_H:
/* dst = *(u32 *)(ul) (src + off) */
case BPF_LDX | BPF_MEM | BPF_W:
case BPF_LDX | BPF_MEMSX | BPF_W:
case BPF_LDX | BPF_PROBE_MEM | BPF_W:
case BPF_LDX | BPF_PROBE_MEMSX | BPF_W:
/* dst = *(u64 *)(ul) (src + off) */
case BPF_LDX | BPF_MEM | BPF_DW:
case BPF_LDX | BPF_PROBE_MEM | BPF_DW:
/*
* As PTR_TO_BTF_ID that uses BPF_PROBE_MEM mode could either be a valid
* kernel pointer or NULL but not a userspace address, execute BPF_PROBE_MEM
* load only if addr is kernel address (see is_kernel_addr()), otherwise
* set dst_reg=0 and move on.
*/
if (BPF_MODE(code) == BPF_PROBE_MEM || BPF_MODE(code) == BPF_PROBE_MEMSX) {
EMIT(PPC_RAW_ADDI(tmp1_reg, src_reg, off));
if (IS_ENABLED(CONFIG_PPC_BOOK3E_64))
PPC_LI64(tmp2_reg, 0x8000000000000000ul);
else /* BOOK3S_64 */
PPC_LI64(tmp2_reg, PAGE_OFFSET);
EMIT(PPC_RAW_CMPLD(tmp1_reg, tmp2_reg));
PPC_BCC_SHORT(COND_GT, (ctx->idx + 3) * 4);
EMIT(PPC_RAW_LI(dst_reg, 0));
/*
* Check if 'off' is word aligned for BPF_DW, because
* we might generate two instructions.
*/
if ((BPF_SIZE(code) == BPF_DW ||
(BPF_SIZE(code) == BPF_B && BPF_MODE(code) == BPF_PROBE_MEMSX)) &&
(off & 3))
PPC_JMP((ctx->idx + 3) * 4);
else
PPC_JMP((ctx->idx + 2) * 4);
}
if (BPF_MODE(code) == BPF_MEMSX || BPF_MODE(code) == BPF_PROBE_MEMSX) {
switch (size) {
case BPF_B:
EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off));
EMIT(PPC_RAW_EXTSB(dst_reg, dst_reg));
break;
case BPF_H:
EMIT(PPC_RAW_LHA(dst_reg, src_reg, off));
break;
case BPF_W:
EMIT(PPC_RAW_LWA(dst_reg, src_reg, off));
break;
}
} else {
switch (size) {
case BPF_B:
EMIT(PPC_RAW_LBZ(dst_reg, src_reg, off));
break;
case BPF_H:
EMIT(PPC_RAW_LHZ(dst_reg, src_reg, off));
break;
case BPF_W:
EMIT(PPC_RAW_LWZ(dst_reg, src_reg, off));
break;
case BPF_DW:
if (off % 4) {
EMIT(PPC_RAW_LI(tmp1_reg, off));
EMIT(PPC_RAW_LDX(dst_reg, src_reg, tmp1_reg));
} else {
EMIT(PPC_RAW_LD(dst_reg, src_reg, off));
}
break;
}
}
if (size != BPF_DW && insn_is_zext(&insn[i + 1]))
addrs[++i] = ctx->idx * 4;
if (BPF_MODE(code) == BPF_PROBE_MEM) {
ret = bpf_add_extable_entry(fp, image, fimage, pass, ctx,
ctx->idx - 1, 4, dst_reg);
if (ret)
return ret;
}
break;
/*
* Doubleword load
* 16 byte instruction that uses two 'struct bpf_insn'
*/
case BPF_LD | BPF_IMM | BPF_DW: /* dst = (u64) imm */
imm64 = ((u64)(u32) insn[i].imm) |
(((u64)(u32) insn[i+1].imm) << 32);
tmp_idx = ctx->idx;
PPC_LI64(dst_reg, imm64);
/* padding to allow full 5 instructions for later patching */
if (!image)
for (j = ctx->idx - tmp_idx; j < 5; j++)
EMIT(PPC_RAW_NOP());
/* Adjust for two bpf instructions */
addrs[++i] = ctx->idx * 4;
break;
/*
* Return/Exit
*/
case BPF_JMP | BPF_EXIT:
/*
* If this isn't the very last instruction, branch to
* the epilogue. If we _are_ the last instruction,
* we'll just fall through to the epilogue.
*/
if (i != flen - 1) {
ret = bpf_jit_emit_exit_insn(image, ctx, tmp1_reg, exit_addr);
if (ret)
return ret;
}
/* else fall through to the epilogue */
break;
/*
* Call kernel helper or bpf function
*/
case BPF_JMP | BPF_CALL:
ctx->seen |= SEEN_FUNC;
ret = bpf_jit_get_func_addr(fp, &insn[i], extra_pass,
&func_addr, &func_addr_fixed);
if (ret < 0)
return ret;
ret = bpf_jit_emit_func_call_rel(image, fimage, ctx, func_addr);
if (ret)
return ret;
/* move return value from r3 to BPF_REG_0 */
EMIT(PPC_RAW_MR(bpf_to_ppc(BPF_REG_0), _R3));
break;
/*
* Jumps and branches
*/
case BPF_JMP | BPF_JA:
PPC_JMP(addrs[i + 1 + off]);
break;
case BPF_JMP32 | BPF_JA:
PPC_JMP(addrs[i + 1 + imm]);
break;
case BPF_JMP | BPF_JGT | BPF_K:
case BPF_JMP | BPF_JGT | BPF_X:
case BPF_JMP | BPF_JSGT | BPF_K:
case BPF_JMP | BPF_JSGT | BPF_X:
case BPF_JMP32 | BPF_JGT | BPF_K:
case BPF_JMP32 | BPF_JGT | BPF_X:
case BPF_JMP32 | BPF_JSGT | BPF_K:
case BPF_JMP32 | BPF_JSGT | BPF_X:
true_cond = COND_GT;
goto cond_branch;
case BPF_JMP | BPF_JLT | BPF_K:
case BPF_JMP | BPF_JLT | BPF_X:
case BPF_JMP | BPF_JSLT | BPF_K:
case BPF_JMP | BPF_JSLT | BPF_X:
case BPF_JMP32 | BPF_JLT | BPF_K:
case BPF_JMP32 | BPF_JLT | BPF_X:
case BPF_JMP32 | BPF_JSLT | BPF_K:
case BPF_JMP32 | BPF_JSLT | BPF_X:
true_cond = COND_LT;
goto cond_branch;
case BPF_JMP | BPF_JGE | BPF_K:
case BPF_JMP | BPF_JGE | BPF_X:
case BPF_JMP | BPF_JSGE | BPF_K:
case BPF_JMP | BPF_JSGE | BPF_X:
case BPF_JMP32 | BPF_JGE | BPF_K:
case BPF_JMP32 | BPF_JGE | BPF_X:
case BPF_JMP32 | BPF_JSGE | BPF_K:
case BPF_JMP32 | BPF_JSGE | BPF_X:
true_cond = COND_GE;
goto cond_branch;
case BPF_JMP | BPF_JLE | BPF_K:
case BPF_JMP | BPF_JLE | BPF_X:
case BPF_JMP | BPF_JSLE | BPF_K:
case BPF_JMP | BPF_JSLE | BPF_X:
case BPF_JMP32 | BPF_JLE | BPF_K:
case BPF_JMP32 | BPF_JLE | BPF_X:
case BPF_JMP32 | BPF_JSLE | BPF_K:
case BPF_JMP32 | BPF_JSLE | BPF_X:
true_cond = COND_LE;
goto cond_branch;
case BPF_JMP | BPF_JEQ | BPF_K:
case BPF_JMP | BPF_JEQ | BPF_X:
case BPF_JMP32 | BPF_JEQ | BPF_K:
case BPF_JMP32 | BPF_JEQ | BPF_X:
true_cond = COND_EQ;
goto cond_branch;
case BPF_JMP | BPF_JNE | BPF_K:
case BPF_JMP | BPF_JNE | BPF_X:
case BPF_JMP32 | BPF_JNE | BPF_K:
case BPF_JMP32 | BPF_JNE | BPF_X:
true_cond = COND_NE;
goto cond_branch;
case BPF_JMP | BPF_JSET | BPF_K:
case BPF_JMP | BPF_JSET | BPF_X:
case BPF_JMP32 | BPF_JSET | BPF_K:
case BPF_JMP32 | BPF_JSET | BPF_X:
true_cond = COND_NE;
/* Fall through */
cond_branch:
switch (code) {
case BPF_JMP | BPF_JGT | BPF_X:
case BPF_JMP | BPF_JLT | BPF_X:
case BPF_JMP | BPF_JGE | BPF_X:
case BPF_JMP | BPF_JLE | BPF_X:
case BPF_JMP | BPF_JEQ | BPF_X:
case BPF_JMP | BPF_JNE | BPF_X:
case BPF_JMP32 | BPF_JGT | BPF_X:
case BPF_JMP32 | BPF_JLT | BPF_X:
case BPF_JMP32 | BPF_JGE | BPF_X:
case BPF_JMP32 | BPF_JLE | BPF_X:
case BPF_JMP32 | BPF_JEQ | BPF_X:
case BPF_JMP32 | BPF_JNE | BPF_X:
/* unsigned comparison */
if (BPF_CLASS(code) == BPF_JMP32)
EMIT(PPC_RAW_CMPLW(dst_reg, src_reg));
else
EMIT(PPC_RAW_CMPLD(dst_reg, src_reg));
break;
case BPF_JMP | BPF_JSGT | BPF_X:
case BPF_JMP | BPF_JSLT | BPF_X:
case BPF_JMP | BPF_JSGE | BPF_X:
case BPF_JMP | BPF_JSLE | BPF_X:
case BPF_JMP32 | BPF_JSGT | BPF_X:
case BPF_JMP32 | BPF_JSLT | BPF_X:
case BPF_JMP32 | BPF_JSGE | BPF_X:
case BPF_JMP32 | BPF_JSLE | BPF_X:
/* signed comparison */
if (BPF_CLASS(code) == BPF_JMP32)
EMIT(PPC_RAW_CMPW(dst_reg, src_reg));
else
EMIT(PPC_RAW_CMPD(dst_reg, src_reg));
break;
case BPF_JMP | BPF_JSET | BPF_X:
case BPF_JMP32 | BPF_JSET | BPF_X:
if (BPF_CLASS(code) == BPF_JMP) {
EMIT(PPC_RAW_AND_DOT(tmp1_reg, dst_reg, src_reg));
} else {
EMIT(PPC_RAW_AND(tmp1_reg, dst_reg, src_reg));
EMIT(PPC_RAW_RLWINM_DOT(tmp1_reg, tmp1_reg, 0, 0, 31));
}
break;
case BPF_JMP | BPF_JNE | BPF_K:
case BPF_JMP | BPF_JEQ | BPF_K:
case BPF_JMP | BPF_JGT | BPF_K:
case BPF_JMP | BPF_JLT | BPF_K:
case BPF_JMP | BPF_JGE | BPF_K:
case BPF_JMP | BPF_JLE | BPF_K:
case BPF_JMP32 | BPF_JNE | BPF_K:
case BPF_JMP32 | BPF_JEQ | BPF_K:
case BPF_JMP32 | BPF_JGT | BPF_K:
case BPF_JMP32 | BPF_JLT | BPF_K:
case BPF_JMP32 | BPF_JGE | BPF_K:
case BPF_JMP32 | BPF_JLE | BPF_K:
{
bool is_jmp32 = BPF_CLASS(code) == BPF_JMP32;
/*
* Need sign-extended load, so only positive
* values can be used as imm in cmpldi
*/
if (imm >= 0 && imm < 32768) {
if (is_jmp32)
EMIT(PPC_RAW_CMPLWI(dst_reg, imm));
else
EMIT(PPC_RAW_CMPLDI(dst_reg, imm));
} else {
/* sign-extending load */
PPC_LI32(tmp1_reg, imm);
/* ... but unsigned comparison */
if (is_jmp32)
EMIT(PPC_RAW_CMPLW(dst_reg, tmp1_reg));
else
EMIT(PPC_RAW_CMPLD(dst_reg, tmp1_reg));
}
break;
}
case BPF_JMP | BPF_JSGT | BPF_K:
case BPF_JMP | BPF_JSLT | BPF_K:
case BPF_JMP | BPF_JSGE | BPF_K:
case BPF_JMP | BPF_JSLE | BPF_K:
case BPF_JMP32 | BPF_JSGT | BPF_K:
case BPF_JMP32 | BPF_JSLT | BPF_K:
case BPF_JMP32 | BPF_JSGE | BPF_K:
case BPF_JMP32 | BPF_JSLE | BPF_K:
{
bool is_jmp32 = BPF_CLASS(code) == BPF_JMP32;
/*
* signed comparison, so any 16-bit value
* can be used in cmpdi
*/
if (imm >= -32768 && imm < 32768) {
if (is_jmp32)
EMIT(PPC_RAW_CMPWI(dst_reg, imm));
else
EMIT(PPC_RAW_CMPDI(dst_reg, imm));
} else {
PPC_LI32(tmp1_reg, imm);
if (is_jmp32)
EMIT(PPC_RAW_CMPW(dst_reg, tmp1_reg));
else
EMIT(PPC_RAW_CMPD(dst_reg, tmp1_reg));
}
break;
}
case BPF_JMP | BPF_JSET | BPF_K:
case BPF_JMP32 | BPF_JSET | BPF_K:
/* andi does not sign-extend the immediate */
if (imm >= 0 && imm < 32768)
/* PPC_ANDI is _only/always_ dot-form */
EMIT(PPC_RAW_ANDI(tmp1_reg, dst_reg, imm));
else {
PPC_LI32(tmp1_reg, imm);
if (BPF_CLASS(code) == BPF_JMP) {
EMIT(PPC_RAW_AND_DOT(tmp1_reg, dst_reg,
tmp1_reg));
} else {
EMIT(PPC_RAW_AND(tmp1_reg, dst_reg, tmp1_reg));
EMIT(PPC_RAW_RLWINM_DOT(tmp1_reg, tmp1_reg,
0, 0, 31));
}
}
break;
}
PPC_BCC(true_cond, addrs[i + 1 + off]);
break;
/*
* Tail call
*/
case BPF_JMP | BPF_TAIL_CALL:
ctx->seen |= SEEN_TAILCALL;
ret = bpf_jit_emit_tail_call(image, ctx, addrs[i + 1]);
if (ret < 0)
return ret;
break;
default:
/*
* The filter contains something cruel & unusual.
* We don't handle it, but also there shouldn't be
* anything missing from our list.
*/
pr_err_ratelimited("eBPF filter opcode %04x (@%d) unsupported\n",
code, i);
return -ENOTSUPP;
}
}
/* Set end-of-body-code address for exit. */
addrs[i] = ctx->idx * 4;
return 0;
}
Reference in New Issue View Git Blame Copy Permalink