[PATCH v2 4/8] powerpc/bpf: Move common functions into bpf_jit_comp.c
Christophe Leroy
christophe.leroy at csgroup.eu
Tue Mar 23 03:37:49 AEDT 2021
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 at csgroup.eu>
---
arch/powerpc/net/Makefile | 2 +-
arch/powerpc/net/bpf_jit.h | 6 +
arch/powerpc/net/bpf_jit_comp.c | 269 ++++++++++++++++++++++++++++++
arch/powerpc/net/bpf_jit_comp64.c | 263 +----------------------------
4 files changed, 281 insertions(+), 259 deletions(-)
create mode 100644 arch/powerpc/net/bpf_jit_comp.c
diff --git a/arch/powerpc/net/Makefile b/arch/powerpc/net/Makefile
index 52c939cef5b2..969cde177880 100644
--- a/arch/powerpc/net/Makefile
+++ b/arch/powerpc/net/Makefile
@@ -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
diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h
index b8fa6908fc5e..b34abfce15a6 100644
--- a/arch/powerpc/net/bpf_jit.h
+++ b/arch/powerpc/net/bpf_jit.h
@@ -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
diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
new file mode 100644
index 000000000000..efac89964873
--- /dev/null
+++ b/arch/powerpc/net/bpf_jit_comp.c
@@ -0,0 +1,269 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * eBPF JIT compiler
+ *
+ * Copyright 2016 Naveen N. Rao <naveen.n.rao at 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);
+}
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index 111451bc5cc0..8a1f9fb00e78 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -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 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image,
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);
-}
--
2.25.0
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