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powerpc/bpf: Move common functions into bpf_jit_comp.c

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Move into bpf_jit_comp.c the functions that will remain common to
PPC64 and PPC32 when we add support of EBPF for PPC32.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2c339d77fb168ef12b213ccddfee3cb6c8ce8ae1.1616430991.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2021-03-22 16:37:49 +00:00 committed by Michael Ellerman
parent f1b1583d5f
commit 4ea76e90a9
4 changed files with 281 additions and 259 deletions
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2
arch/powerpc/net/Makefile
View File

@ -2,4 +2,4 @@
#
# Arch-specific network modules
#
obj-$(CONFIG_BPF_JIT) += bpf_jit_comp64.o
obj-$(CONFIG_BPF_JIT) += bpf_jit_comp.o bpf_jit_comp64.o

6
arch/powerpc/net/bpf_jit.h
View File

@ -143,6 +143,12 @@ static inline void bpf_set_seen_register(struct codegen_context *ctx, int i)
ctx->seen |= 1 << (31 - i);
}
void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func);
int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx,
u32 *addrs, bool extra_pass);
void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx);
void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx);
#endif
#endif

269
arch/powerpc/net/bpf_jit_comp.c Normal file
View File

@ -0,0 +1,269 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* 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 "bpf_jit.h"
static void bpf_jit_fill_ill_insns(void *area, unsigned int size)
{
memset32(area, BREAKPOINT_INSTRUCTION, size / 4);
}
/* Fix the branch target addresses for subprog calls */
static int bpf_jit_fixup_subprog_calls(struct bpf_prog *fp, u32 *image,
struct codegen_context *ctx, u32 *addrs)
{
const struct bpf_insn *insn = fp->insnsi;
bool func_addr_fixed;
u64 func_addr;
u32 tmp_idx;
int i, ret;
for (i = 0; i < fp->len; i++) {
/*
* During the extra pass, only the branch target addresses for
* the subprog calls need to be fixed. All other instructions
* can left untouched.
*
* The JITed image length does not change because we already
* ensure that the JITed instruction sequence for these calls
* are of fixed length by padding them with NOPs.
*/
if (insn[i].code == (BPF_JMP | BPF_CALL) &&
insn[i].src_reg == BPF_PSEUDO_CALL) {
ret = bpf_jit_get_func_addr(fp, &insn[i], true,
&func_addr,
&func_addr_fixed);
if (ret < 0)
return ret;
/*
* Save ctx->idx as this would currently point to the
* end of the JITed image and set it to the offset of
* the instruction sequence corresponding to the
* subprog call temporarily.
*/
tmp_idx = ctx->idx;
ctx->idx = addrs[i] / 4;
bpf_jit_emit_func_call_rel(image, ctx, func_addr);
/*
* Restore ctx->idx here. This is safe as the length
* of the JITed sequence remains unchanged.
*/
ctx->idx = tmp_idx;
}
}
return 0;
}
struct powerpc64_jit_data {
struct bpf_binary_header *header;
u32 *addrs;
u8 *image;
u32 proglen;
struct codegen_context ctx;
};
bool bpf_jit_needs_zext(void)
{
return true;
}
struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
{
u32 proglen;
u32 alloclen;
u8 *image = NULL;
u32 *code_base;
u32 *addrs;
struct powerpc64_jit_data *jit_data;
struct codegen_context cgctx;
int pass;
int flen;
struct bpf_binary_header *bpf_hdr;
struct bpf_prog *org_fp = fp;
struct bpf_prog *tmp_fp;
bool bpf_blinded = false;
bool extra_pass = false;
if (!fp->jit_requested)
return org_fp;
tmp_fp = bpf_jit_blind_constants(org_fp);
if (IS_ERR(tmp_fp))
return org_fp;
if (tmp_fp != org_fp) {
bpf_blinded = true;
fp = tmp_fp;
}
jit_data = fp->aux->jit_data;
if (!jit_data) {
jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL);
if (!jit_data) {
fp = org_fp;
goto out;
}
fp->aux->jit_data = jit_data;
}
flen = fp->len;
addrs = jit_data->addrs;
if (addrs) {
cgctx = jit_data->ctx;
image = jit_data->image;
bpf_hdr = jit_data->header;
proglen = jit_data->proglen;
alloclen = proglen + FUNCTION_DESCR_SIZE;
extra_pass = true;
goto skip_init_ctx;
}
addrs = kcalloc(flen + 1, sizeof(*addrs), GFP_KERNEL);
if (addrs == NULL) {
fp = org_fp;
goto out_addrs;
}
memset(&cgctx, 0, sizeof(struct codegen_context));
/* Make sure that the stack is quadword aligned. */
cgctx.stack_size = round_up(fp->aux->stack_depth, 16);
/* Scouting faux-generate pass 0 */
if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) {
/* We hit something illegal or unsupported. */
fp = org_fp;
goto out_addrs;
}
/*
* If we have seen a tail call, we need a second pass.
* This is because bpf_jit_emit_common_epilogue() is called
* from bpf_jit_emit_tail_call() with a not yet stable ctx->seen.
*/
if (cgctx.seen & SEEN_TAILCALL) {
cgctx.idx = 0;
if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) {
fp = org_fp;
goto out_addrs;
}
}
/*
* Pretend to build prologue, given the features we've seen. This will
* update ctgtx.idx as it pretends to output instructions, then we can
* calculate total size from idx.
*/
bpf_jit_build_prologue(0, &cgctx);
bpf_jit_build_epilogue(0, &cgctx);
proglen = cgctx.idx * 4;
alloclen = proglen + FUNCTION_DESCR_SIZE;
bpf_hdr = bpf_jit_binary_alloc(alloclen, &image, 4, bpf_jit_fill_ill_insns);
if (!bpf_hdr) {
fp = org_fp;
goto out_addrs;
}
skip_init_ctx:
code_base = (u32 *)(image + FUNCTION_DESCR_SIZE);
if (extra_pass) {
/*
* Do not touch the prologue and epilogue as they will remain
* unchanged. Only fix the branch target address for subprog
* calls in the body.
*
* This does not change the offsets and lengths of the subprog
* call instruction sequences and hence, the size of the JITed
* image as well.
*/
bpf_jit_fixup_subprog_calls(fp, code_base, &cgctx, addrs);
/* There is no need to perform the usual passes. */
goto skip_codegen_passes;
}
/* Code generation passes 1-2 */
for (pass = 1; pass < 3; pass++) {
/* Now build the prologue, body code & epilogue for real. */
cgctx.idx = 0;
bpf_jit_build_prologue(code_base, &cgctx);
bpf_jit_build_body(fp, code_base, &cgctx, addrs, extra_pass);
bpf_jit_build_epilogue(code_base, &cgctx);
if (bpf_jit_enable > 1)
pr_info("Pass %d: shrink = %d, seen = 0x%x\n", pass,
proglen - (cgctx.idx * 4), cgctx.seen);
}
skip_codegen_passes:
if (bpf_jit_enable > 1)
/*
* Note that we output the base address of the code_base
* rather than image, since opcodes are in code_base.
*/
bpf_jit_dump(flen, proglen, pass, code_base);
#ifdef PPC64_ELF_ABI_v1
/* Function descriptor nastiness: Address + TOC */
((u64 *)image)[0] = (u64)code_base;
((u64 *)image)[1] = local_paca->kernel_toc;
#endif
fp->bpf_func = (void *)image;
fp->jited = 1;
fp->jited_len = alloclen;
bpf_flush_icache(bpf_hdr, (u8 *)bpf_hdr + (bpf_hdr->pages * PAGE_SIZE));
if (!fp->is_func || extra_pass) {
bpf_prog_fill_jited_linfo(fp, addrs);
out_addrs:
kfree(addrs);
kfree(jit_data);
fp->aux->jit_data = NULL;
} else {
jit_data->addrs = addrs;
jit_data->ctx = cgctx;
jit_data->proglen = proglen;
jit_data->image = image;
jit_data->header = bpf_hdr;
}
out:
if (bpf_blinded)
bpf_jit_prog_release_other(fp, fp == org_fp ? tmp_fp : org_fp);
return fp;
}
/* Overriding bpf_jit_free() as we don't set images read-only. */
void bpf_jit_free(struct bpf_prog *fp)
{
unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK;
struct bpf_binary_header *bpf_hdr = (void *)addr;
if (fp->jited)
bpf_jit_binary_free(bpf_hdr);
bpf_prog_unlock_free(fp);
}

263
arch/powerpc/net/bpf_jit_comp64.c
View File

@ -18,11 +18,6 @@
#include "bpf_jit64.h"
static void bpf_jit_fill_ill_insns(void *area, unsigned int size)
{
memset32(area, BREAKPOINT_INSTRUCTION, size/4);
}
static inline bool bpf_has_stack_frame(struct codegen_context *ctx)
{
/*
@ -69,7 +64,7 @@ static int bpf_jit_stack_offsetof(struct codegen_context *ctx, int reg)
BUG();
}
static void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
void bpf_jit_build_prologue(u32 *image, struct codegen_context *ctx)
{
int i;
@ -136,7 +131,7 @@ static void bpf_jit_emit_common_epilogue(u32 *image, struct codegen_context *ctx
}
}
static void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx)
void bpf_jit_build_epilogue(u32 *image, struct codegen_context *ctx)
{
bpf_jit_emit_common_epilogue(image, ctx);
@ -171,8 +166,7 @@ static void bpf_jit_emit_func_call_hlp(u32 *image, struct codegen_context *ctx,
EMIT(PPC_RAW_BLRL());
}
static void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx,
u64 func)
void bpf_jit_emit_func_call_rel(u32 *image, struct codegen_context *ctx, u64 func)
{
unsigned int i, ctx_idx = ctx->idx;
@ -273,9 +267,8 @@ static void bpf_jit_emit_tail_call(u32 *image, struct codegen_context *ctx, u32
}
/* Assemble the body code between the prologue & epilogue */
static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
struct codegen_context *ctx,
u32 *addrs, bool extra_pass)
int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context *ctx,
u32 *addrs, bool extra_pass)
{
const struct bpf_insn *insn = fp->insnsi;
int flen = fp->len;
@ -1010,249 +1003,3 @@ cond_branch:
return 0;
}
/* Fix the branch target addresses for subprog calls */
static int bpf_jit_fixup_subprog_calls(struct bpf_prog *fp, u32 *image,
struct codegen_context *ctx, u32 *addrs)
{
const struct bpf_insn *insn = fp->insnsi;
bool func_addr_fixed;
u64 func_addr;
u32 tmp_idx;
int i, ret;
for (i = 0; i < fp->len; i++) {
/*
* During the extra pass, only the branch target addresses for
* the subprog calls need to be fixed. All other instructions
* can left untouched.
*
* The JITed image length does not change because we already
* ensure that the JITed instruction sequence for these calls
* are of fixed length by padding them with NOPs.
*/
if (insn[i].code == (BPF_JMP | BPF_CALL) &&
insn[i].src_reg == BPF_PSEUDO_CALL) {
ret = bpf_jit_get_func_addr(fp, &insn[i], true,
&func_addr,
&func_addr_fixed);
if (ret < 0)
return ret;
/*
* Save ctx->idx as this would currently point to the
* end of the JITed image and set it to the offset of
* the instruction sequence corresponding to the
* subprog call temporarily.
*/
tmp_idx = ctx->idx;
ctx->idx = addrs[i] / 4;
bpf_jit_emit_func_call_rel(image, ctx, func_addr);
/*
* Restore ctx->idx here. This is safe as the length
* of the JITed sequence remains unchanged.
*/
ctx->idx = tmp_idx;
}
}
return 0;
}
struct powerpc64_jit_data {
struct bpf_binary_header *header;
u32 *addrs;
u8 *image;
u32 proglen;
struct codegen_context ctx;
};
bool bpf_jit_needs_zext(void)
{
return true;
}
struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
{
u32 proglen;
u32 alloclen;
u8 *image = NULL;
u32 *code_base;
u32 *addrs;
struct powerpc64_jit_data *jit_data;
struct codegen_context cgctx;
int pass;
int flen;
struct bpf_binary_header *bpf_hdr;
struct bpf_prog *org_fp = fp;
struct bpf_prog *tmp_fp;
bool bpf_blinded = false;
bool extra_pass = false;
if (!fp->jit_requested)
return org_fp;
tmp_fp = bpf_jit_blind_constants(org_fp);
if (IS_ERR(tmp_fp))
return org_fp;
if (tmp_fp != org_fp) {
bpf_blinded = true;
fp = tmp_fp;
}
jit_data = fp->aux->jit_data;
if (!jit_data) {
jit_data = kzalloc(sizeof(*jit_data), GFP_KERNEL);
if (!jit_data) {
fp = org_fp;
goto out;
}
fp->aux->jit_data = jit_data;
}
flen = fp->len;
addrs = jit_data->addrs;
if (addrs) {
cgctx = jit_data->ctx;
image = jit_data->image;
bpf_hdr = jit_data->header;
proglen = jit_data->proglen;
alloclen = proglen + FUNCTION_DESCR_SIZE;
extra_pass = true;
goto skip_init_ctx;
}
addrs = kcalloc(flen + 1, sizeof(*addrs), GFP_KERNEL);
if (addrs == NULL) {
fp = org_fp;
goto out_addrs;
}
memset(&cgctx, 0, sizeof(struct codegen_context));
/* Make sure that the stack is quadword aligned. */
cgctx.stack_size = round_up(fp->aux->stack_depth, 16);
/* Scouting faux-generate pass 0 */
if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) {
/* We hit something illegal or unsupported. */
fp = org_fp;
goto out_addrs;
}
/*
* If we have seen a tail call, we need a second pass.
* This is because bpf_jit_emit_common_epilogue() is called
* from bpf_jit_emit_tail_call() with a not yet stable ctx->seen.
*/
if (cgctx.seen & SEEN_TAILCALL) {
cgctx.idx = 0;
if (bpf_jit_build_body(fp, 0, &cgctx, addrs, false)) {
fp = org_fp;
goto out_addrs;
}
}
/*
* Pretend to build prologue, given the features we've seen. This will
* update ctgtx.idx as it pretends to output instructions, then we can
* calculate total size from idx.
*/
bpf_jit_build_prologue(0, &cgctx);
bpf_jit_build_epilogue(0, &cgctx);
proglen = cgctx.idx * 4;
alloclen = proglen + FUNCTION_DESCR_SIZE;
bpf_hdr = bpf_jit_binary_alloc(alloclen, &image, 4,
bpf_jit_fill_ill_insns);
if (!bpf_hdr) {
fp = org_fp;
goto out_addrs;
}
skip_init_ctx:
code_base = (u32 *)(image + FUNCTION_DESCR_SIZE);
if (extra_pass) {
/*
* Do not touch the prologue and epilogue as they will remain
* unchanged. Only fix the branch target address for subprog
* calls in the body.
*
* This does not change the offsets and lengths of the subprog
* call instruction sequences and hence, the size of the JITed
* image as well.
*/
bpf_jit_fixup_subprog_calls(fp, code_base, &cgctx, addrs);
/* There is no need to perform the usual passes. */
goto skip_codegen_passes;
}
/* Code generation passes 1-2 */
for (pass = 1; pass < 3; pass++) {
/* Now build the prologue, body code & epilogue for real. */
cgctx.idx = 0;
bpf_jit_build_prologue(code_base, &cgctx);
bpf_jit_build_body(fp, code_base, &cgctx, addrs, extra_pass);
bpf_jit_build_epilogue(code_base, &cgctx);
if (bpf_jit_enable > 1)
pr_info("Pass %d: shrink = %d, seen = 0x%x\n", pass,
proglen - (cgctx.idx * 4), cgctx.seen);
}
skip_codegen_passes:
if (bpf_jit_enable > 1)
/*
* Note that we output the base address of the code_base
* rather than image, since opcodes are in code_base.
*/
bpf_jit_dump(flen, proglen, pass, code_base);
#ifdef PPC64_ELF_ABI_v1
/* Function descriptor nastiness: Address + TOC */
((u64 *)image)[0] = (u64)code_base;
((u64 *)image)[1] = local_paca->kernel_toc;
#endif
fp->bpf_func = (void *)image;
fp->jited = 1;
fp->jited_len = alloclen;
bpf_flush_icache(bpf_hdr, (u8 *)bpf_hdr + (bpf_hdr->pages * PAGE_SIZE));
if (!fp->is_func || extra_pass) {
bpf_prog_fill_jited_linfo(fp, addrs);
out_addrs:
kfree(addrs);
kfree(jit_data);
fp->aux->jit_data = NULL;
} else {
jit_data->addrs = addrs;
jit_data->ctx = cgctx;
jit_data->proglen = proglen;
jit_data->image = image;
jit_data->header = bpf_hdr;
}
out:
if (bpf_blinded)
bpf_jit_prog_release_other(fp, fp == org_fp ? tmp_fp : org_fp);
return fp;
}
/* Overriding bpf_jit_free() as we don't set images read-only. */
void bpf_jit_free(struct bpf_prog *fp)
{
unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK;
struct bpf_binary_header *bpf_hdr = (void *)addr;
if (fp->jited)
bpf_jit_binary_free(bpf_hdr);
bpf_prog_unlock_free(fp);
}