Merging upstream version 6.7.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 117 insertions, 32 deletions

diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
index 37043dfc1a..0f9a217833 100644
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c
@@ -13,9 +13,13 @@
 #include <linux/netdevice.h>
 #include <linux/filter.h>
 #include <linux/if_vlan.h>
-#include <asm/kprobes.h>
+#include <linux/kernel.h>
+#include <linux/memory.h>
 #include <linux/bpf.h>
 
+#include <asm/kprobes.h>
+#include <asm/code-patching.h>
+
 #include "bpf_jit.h"
 
 static void bpf_jit_fill_ill_insns(void *area, unsigned int size)
@@ -39,10 +43,13 @@ int bpf_jit_emit_exit_insn(u32 *image, struct codegen_context *ctx, int tmp_reg,
 	return 0;
 }
 
-struct powerpc64_jit_data {
-	struct bpf_binary_header *header;
+struct powerpc_jit_data {
+	/* address of rw header */
+	struct bpf_binary_header *hdr;
+	/* address of ro final header */
+	struct bpf_binary_header *fhdr;
 	u32 *addrs;
-	u8 *image;
+	u8 *fimage;
 	u32 proglen;
 	struct codegen_context ctx;
 };
@@ -59,15 +66,18 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
 	u8 *image = NULL;
 	u32 *code_base;
 	u32 *addrs;
-	struct powerpc64_jit_data *jit_data;
+	struct powerpc_jit_data *jit_data;
 	struct codegen_context cgctx;
 	int pass;
 	int flen;
-	struct bpf_binary_header *bpf_hdr;
+	struct bpf_binary_header *fhdr = NULL;
+	struct bpf_binary_header *hdr = NULL;
 	struct bpf_prog *org_fp = fp;
 	struct bpf_prog *tmp_fp;
 	bool bpf_blinded = false;
 	bool extra_pass = false;
+	u8 *fimage = NULL;
+	u32 *fcode_base;
 	u32 extable_len;
 	u32 fixup_len;
 
@@ -97,9 +107,16 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
 	addrs = jit_data->addrs;
 	if (addrs) {
 		cgctx = jit_data->ctx;
-		image = jit_data->image;
-		bpf_hdr = jit_data->header;
+		/*
+		 * JIT compiled to a writable location (image/code_base) first.
+		 * It is then moved to the readonly final location (fimage/fcode_base)
+		 * using instruction patching.
+		 */
+		fimage = jit_data->fimage;
+		fhdr = jit_data->fhdr;
 		proglen = jit_data->proglen;
+		hdr = jit_data->hdr;
+		image = (void *)hdr + ((void *)fimage - (void *)fhdr);
 		extra_pass = true;
 		/* During extra pass, ensure index is reset before repopulating extable entries */
 		cgctx.exentry_idx = 0;
@@ -119,7 +136,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
 	cgctx.stack_size = round_up(fp->aux->stack_depth, 16);
 
 	/* Scouting faux-generate pass 0 */
-	if (bpf_jit_build_body(fp, 0, &cgctx, addrs, 0, false)) {
+	if (bpf_jit_build_body(fp, NULL, NULL, &cgctx, addrs, 0, false)) {
 		/* We hit something illegal or unsupported. */
 		fp = org_fp;
 		goto out_addrs;
@@ -134,7 +151,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
 	 */
 	if (cgctx.seen & SEEN_TAILCALL || !is_offset_in_branch_range((long)cgctx.idx * 4)) {
 		cgctx.idx = 0;
-		if (bpf_jit_build_body(fp, 0, &cgctx, addrs, 0, false)) {
+		if (bpf_jit_build_body(fp, NULL, NULL, &cgctx, addrs, 0, false)) {
 			fp = org_fp;
 			goto out_addrs;
 		}
@@ -146,9 +163,9 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
 	 * 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_prologue(NULL, &cgctx);
 	addrs[fp->len] = cgctx.idx * 4;
-	bpf_jit_build_epilogue(0, &cgctx);
+	bpf_jit_build_epilogue(NULL, &cgctx);
 
 	fixup_len = fp->aux->num_exentries * BPF_FIXUP_LEN * 4;
 	extable_len = fp->aux->num_exentries * sizeof(struct exception_table_entry);
@@ -156,17 +173,19 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
 	proglen = cgctx.idx * 4;
 	alloclen = proglen + FUNCTION_DESCR_SIZE + fixup_len + extable_len;
 
-	bpf_hdr = bpf_jit_binary_alloc(alloclen, &image, 4, bpf_jit_fill_ill_insns);
-	if (!bpf_hdr) {
+	fhdr = bpf_jit_binary_pack_alloc(alloclen, &fimage, 4, &hdr, &image,
+					      bpf_jit_fill_ill_insns);
+	if (!fhdr) {
 		fp = org_fp;
 		goto out_addrs;
 	}
 
 	if (extable_len)
-		fp->aux->extable = (void *)image + FUNCTION_DESCR_SIZE + proglen + fixup_len;
+		fp->aux->extable = (void *)fimage + FUNCTION_DESCR_SIZE + proglen + fixup_len;
 
 skip_init_ctx:
 	code_base = (u32 *)(image + FUNCTION_DESCR_SIZE);
+	fcode_base = (u32 *)(fimage + FUNCTION_DESCR_SIZE);
 
 	/* Code generation passes 1-2 */
 	for (pass = 1; pass < 3; pass++) {
@@ -174,8 +193,10 @@ skip_init_ctx:
 		cgctx.idx = 0;
 		cgctx.alt_exit_addr = 0;
 		bpf_jit_build_prologue(code_base, &cgctx);
-		if (bpf_jit_build_body(fp, code_base, &cgctx, addrs, pass, extra_pass)) {
-			bpf_jit_binary_free(bpf_hdr);
+		if (bpf_jit_build_body(fp, code_base, fcode_base, &cgctx, addrs, pass,
+				       extra_pass)) {
+			bpf_arch_text_copy(&fhdr->size, &hdr->size, sizeof(hdr->size));
+			bpf_jit_binary_pack_free(fhdr, hdr);
 			fp = org_fp;
 			goto out_addrs;
 		}
@@ -195,17 +216,19 @@ skip_init_ctx:
 
 #ifdef CONFIG_PPC64_ELF_ABI_V1
 	/* Function descriptor nastiness: Address + TOC */
-	((u64 *)image)[0] = (u64)code_base;
+	((u64 *)image)[0] = (u64)fcode_base;
 	((u64 *)image)[1] = local_paca->kernel_toc;
 #endif
 
-	fp->bpf_func = (void *)image;
+	fp->bpf_func = (void *)fimage;
 	fp->jited = 1;
 	fp->jited_len = proglen + FUNCTION_DESCR_SIZE;
 
-	bpf_flush_icache(bpf_hdr, (u8 *)bpf_hdr + bpf_hdr->size);
 	if (!fp->is_func || extra_pass) {
-		bpf_jit_binary_lock_ro(bpf_hdr);
+		if (bpf_jit_binary_pack_finalize(fp, fhdr, hdr)) {
+			fp = org_fp;
+			goto out_addrs;
+		}
 		bpf_prog_fill_jited_linfo(fp, addrs);
 out_addrs:
 		kfree(addrs);
@@ -215,8 +238,9 @@ out_addrs:
 		jit_data->addrs = addrs;
 		jit_data->ctx = cgctx;
 		jit_data->proglen = proglen;
-		jit_data->image = image;
-		jit_data->header = bpf_hdr;
+		jit_data->fimage = fimage;
+		jit_data->fhdr = fhdr;
+		jit_data->hdr = hdr;
 	}
 
 out:
@@ -230,12 +254,13 @@ out:
  * The caller should check for (BPF_MODE(code) == BPF_PROBE_MEM) before calling
  * this function, as this only applies to BPF_PROBE_MEM, for now.
  */
-int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, int pass, struct codegen_context *ctx,
-			  int insn_idx, int jmp_off, int dst_reg)
+int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, u32 *fimage, int pass,
+			  struct codegen_context *ctx, int insn_idx, int jmp_off,
+			  int dst_reg)
 {
 	off_t offset;
 	unsigned long pc;
-	struct exception_table_entry *ex;
+	struct exception_table_entry *ex, *ex_entry;
 	u32 *fixup;
 
 	/* Populate extable entries only in the last pass */
@@ -246,9 +271,16 @@ int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, int pass, struct code
 	    WARN_ON_ONCE(ctx->exentry_idx >= fp->aux->num_exentries))
 		return -EINVAL;
 
+	/*
+	 * Program is first written to image before copying to the
+	 * final location (fimage). Accordingly, update in the image first.
+	 * As all offsets used are relative, copying as is to the
+	 * final location should be alright.
+	 */
 	pc = (unsigned long)&image[insn_idx];
+	ex = (void *)fp->aux->extable - (void *)fimage + (void *)image;
 
-	fixup = (void *)fp->aux->extable -
+	fixup = (void *)ex -
 		(fp->aux->num_exentries * BPF_FIXUP_LEN * 4) +
 		(ctx->exentry_idx * BPF_FIXUP_LEN * 4);
 
@@ -259,18 +291,71 @@ int bpf_add_extable_entry(struct bpf_prog *fp, u32 *image, int pass, struct code
 	fixup[BPF_FIXUP_LEN - 1] =
 		PPC_RAW_BRANCH((long)(pc + jmp_off) - (long)&fixup[BPF_FIXUP_LEN - 1]);
 
-	ex = &fp->aux->extable[ctx->exentry_idx];
+	ex_entry = &ex[ctx->exentry_idx];
 
-	offset = pc - (long)&ex->insn;
+	offset = pc - (long)&ex_entry->insn;
 	if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN))
 		return -ERANGE;
-	ex->insn = offset;
+	ex_entry->insn = offset;
 
-	offset = (long)fixup - (long)&ex->fixup;
+	offset = (long)fixup - (long)&ex_entry->fixup;
 	if (WARN_ON_ONCE(offset >= 0 || offset < INT_MIN))
 		return -ERANGE;
-	ex->fixup = offset;
+	ex_entry->fixup = offset;
 
 	ctx->exentry_idx++;
 	return 0;
 }
+
+void *bpf_arch_text_copy(void *dst, void *src, size_t len)
+{
+	int err;
+
+	if (WARN_ON_ONCE(core_kernel_text((unsigned long)dst)))
+		return ERR_PTR(-EINVAL);
+
+	mutex_lock(&text_mutex);
+	err = patch_instructions(dst, src, len, false);
+	mutex_unlock(&text_mutex);
+
+	return err ? ERR_PTR(err) : dst;
+}
+
+int bpf_arch_text_invalidate(void *dst, size_t len)
+{
+	u32 insn = BREAKPOINT_INSTRUCTION;
+	int ret;
+
+	if (WARN_ON_ONCE(core_kernel_text((unsigned long)dst)))
+		return -EINVAL;
+
+	mutex_lock(&text_mutex);
+	ret = patch_instructions(dst, &insn, len, true);
+	mutex_unlock(&text_mutex);
+
+	return ret;
+}
+
+void bpf_jit_free(struct bpf_prog *fp)
+{
+	if (fp->jited) {
+		struct powerpc_jit_data *jit_data = fp->aux->jit_data;
+		struct bpf_binary_header *hdr;
+
+		/*
+		 * If we fail the final pass of JIT (from jit_subprogs),
+		 * the program may not be finalized yet. Call finalize here
+		 * before freeing it.
+		 */
+		if (jit_data) {
+			bpf_jit_binary_pack_finalize(fp, jit_data->fhdr, jit_data->hdr);
+			kvfree(jit_data->addrs);
+			kfree(jit_data);
+		}
+		hdr = bpf_jit_binary_pack_hdr(fp);
+		bpf_jit_binary_pack_free(hdr, NULL);
+		WARN_ON_ONCE(!bpf_prog_kallsyms_verify_off(fp));
+	}
+
+	bpf_prog_unlock_free(fp);
+}