Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

8f150cce · Linus Torvalds <[email protected]> · 2026-10-02 12:59:32 -07:00

Pull bpf fixes from Alexei Starovoitov:

 - Fix overflow of backward jump offset in constant blinding
   (Alexei Starovoitov)

 - Fix packet range of packet pointers sharing an id when var_off
   tightens umax of one pointer and not the other (Alexei Starovoitov)

 - Fix objects stuck in free_by_rcu_ttrace list of bpf memalloc
   (Alexei Starovoitov)

 - Fix use-after-free of progs detached from busy trampolines: wait for
   an RCU tasks grace period before freeing trampoline progs, and patch
   detached progs out of trampoline images that are still in use
   (Florent Revest)

 - Hold map BTF for the memory allocator destructor record to fix UAF in
   deferred bpf_mem_alloc destruction (Kumar Kartikeya Dwivedi)

 - Fix missing migration protection in resizable hashtab
   lookup_and_delete batch operation (Ömer Mete Kaya)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Fix missing migration protection in __rhtab_map_lookup_and_delete_batch()
  selftests/bpf: Add a test for objects stuck in free_by_rcu_ttrace
  bpf: Fix objects stuck in free_by_rcu_ttrace
  bpf: Factor out __do_call_rcu_ttrace()
  selftests/bpf: Test packet range of pointers sharing an id
  bpf: Fix packet range of pointers sharing an id
  selftests/bpf: Detach a trampoline prog while a task sleeps before it
  bpf: Skip detached progs in trampoline images that are still in use
  bpf: Wait for an RCU tasks grace period before freeing trampoline progs
  bpf: Hold map BTF for the memory allocator destructor record
  bpf: Fix overflow of jump offset in constant blinding

Commit: 8f150ccedfbd610aa25509ff42365d70fb20478f
Parents: d2dbe503 · de020dc8

Merge commit. Changes below are compared with the first parent: d2dbe503.

Changes

23 files changed · +975 −172

File	Status	Add	Del	Content
arch/arm64/net/bpf_jit_comp.c	modified	+22	−15	View file
arch/loongarch/net/bpf_jit.c	modified	+40	−20	View file
arch/powerpc/net/bpf_jit_comp.c	modified	+23	−22	View file
arch/riscv/net/bpf_jit_comp64.c	modified	+39	−17	View file
arch/s390/net/bpf_jit_comp.c	modified	+30	−16	View file
arch/x86/net/bpf_jit_comp.c	modified	+16	−10	View file
include/linux/bpf.h	modified	+41	−4	View file
kernel/bpf/core.c	modified	+8	−2	View file
kernel/bpf/hashtab.c	modified	+18	−1	View file
kernel/bpf/memalloc.c	modified	+47	−10	View file
kernel/bpf/syscall.c	modified	+18	−1	View file
kernel/bpf/trampoline.c	modified	+68	−17	View file
kernel/bpf/verifier.c	modified	+9	−1	View file
tools/testing/selftests/bpf/prog_tests/bpf_ma_ttrace.c	added	+60	−0	View file
tools/testing/selftests/bpf/prog_tests/bpf_mod_race.c	modified	+1	−33	View file
tools/testing/selftests/bpf/prog_tests/tramp_prog_detach.c	added	+188	−0	View file
tools/testing/selftests/bpf/progs/bpf_ma_ttrace.c	added	+50	−0	View file
tools/testing/selftests/bpf/progs/tramp_prog_detach.c	added	+56	−0	View file
tools/testing/selftests/bpf/progs/verifier_align.c	modified	+3	−3	View file
tools/testing/selftests/bpf/progs/verifier_direct_packet_access.c	modified	+178	−0	View file
tools/testing/selftests/bpf/progs/verifier_meta_access.c	modified	+30	−0	View file
tools/testing/selftests/bpf/testing_helpers.c	modified	+28	−0	View file
tools/testing/selftests/bpf/testing_helpers.h	modified	+2	−0	View file

Only the first 600 diff lines are shown. Download the complete patch.

arch/arm64/net/bpf_jit_comp.c

View file

diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index c5f55d6..c1279fa 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -2418,10 +2418,11 @@ bool bpf_jit_supports_subprog_tailcalls(void)
 	return true;
 }
 
-static void invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_node *node,
-			    int bargs_off, int retval_off, int run_ctx_off,
-			    bool save_ret)
+static void invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_image *im,
+			    struct bpf_tramp_node *node, int bargs_off,
+			    int retval_off, int run_ctx_off, bool save_ret)
 {
+	void *skip;
 	__le32 *branch;
 	u64 enter_prog;
 	u64 exit_prog;
@@ -2431,6 +2432,10 @@ static void invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_node *node,
 	enter_prog = (u64)bpf_trampoline_enter(p);
 	exit_prog = (u64)bpf_trampoline_exit(p);
 
+	/* nop, patched to skip this prog when it is detached */
+	skip = ctx->ro_image + ctx->idx;
+	emit(A64_NOP, ctx);
+
 	if (node->cookie == 0) {
 		/* if cookie is zero, one instruction is enough to store it */
 		emit(A64_STR64I(A64_ZR, A64_SP, run_ctx_off + cookie_off), ctx);
@@ -2483,11 +2488,13 @@ static void invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_node *node,
 	emit(A64_ADD_I(1, A64_R(2), A64_SP, run_ctx_off), ctx);
 
 	emit_call(exit_prog, ctx);
+
+	bpf_tramp_image_add_skip(im, p, skip, ctx->ro_image + ctx->idx);
 }
 
-static void invoke_bpf_mod_ret(struct jit_ctx *ctx, struct bpf_tramp_nodes *tn,
-			       int bargs_off, int retval_off, int run_ctx_off,
-			       __le32 **branches)
+static void invoke_bpf_mod_ret(struct jit_ctx *ctx, struct bpf_tramp_image *im,
+			       struct bpf_tramp_nodes *tn, int bargs_off,
+			       int retval_off, int run_ctx_off, __le32 **branches)
 {
 	int i;
 
@@ -2496,7 +2503,7 @@ static void invoke_bpf_mod_ret(struct jit_ctx *ctx, struct bpf_tramp_nodes *tn,
 	 */
 	emit(A64_STR64I(A64_ZR, A64_SP, retval_off), ctx);
 	for (i = 0; i < tn->nr_nodes; i++) {
-		invoke_bpf_prog(ctx, tn->nodes[i], bargs_off, retval_off,
+		invoke_bpf_prog(ctx, im, tn->nodes[i], bargs_off, retval_off,
 				run_ctx_off, true);
 		/* if (*(u64 *)(sp + retval_off) !=  0)
 		 *	goto do_fexit;
@@ -2882,7 +2889,7 @@ static int prepare_trampoline(struct jit_ctx *ctx, struct bpf_tramp_image *im,
 			store_func_meta(ctx, meta, func_meta_off);
 			cookie_bargs_off--;
 		}
-		invoke_bpf_prog(ctx, fentry->nodes[i], bargs_off,
+		invoke_bpf_prog(ctx, im, fentry->nodes[i], bargs_off,
 				retval_off, run_ctx_off,
 				flags & BPF_TRAMP_F_RET_FENTRY_RET);
 	}
@@ -2893,7 +2900,7 @@ static int prepare_trampoline(struct jit_ctx *ctx, struct bpf_tramp_image *im,
 		if (!branches)
 			return -ENOMEM;
 
-		invoke_bpf_mod_ret(ctx, fmod_ret, bargs_off, retval_off,
+		invoke_bpf_mod_ret(ctx, im, fmod_ret, bargs_off, retval_off,
 				   run_ctx_off, branches);
 	}
 
@@ -2906,9 +2913,6 @@ static int prepare_trampoline(struct jit_ctx *ctx, struct bpf_tramp_image *im,
 		emit(A64_RET(A64_R(10)), ctx);
 		/* store return value */
 		emit(A64_STR64I(A64_R(0), A64_SP, retval_off), ctx);
-		/* reserve a nop for bpf_tramp_image_put */
-		im->ip_after_call = ctx->ro_image + ctx->idx;
-		emit(A64_NOP, ctx);
 	}
 
 	/* update the branches saved in invoke_bpf_mod_ret with cbnz */
@@ -2930,12 +2934,11 @@ static int prepare_trampoline(struct jit_ctx *ctx, struct bpf_tramp_image *im,
 			store_func_meta(ctx, meta, func_meta_off);
 			cookie_bargs_off--;
 		}
-		invoke_bpf_prog(ctx, fexit->nodes[i], bargs_off, retval_off,
+		invoke_bpf_prog(ctx, im, fexit->nodes[i], bargs_off, retval_off,
 				run_ctx_off, false);
 	}
 
 	if (flags & BPF_TRAMP_F_CALL_ORIG) {
-		im->ip_epilogue = ctx->ro_image + ctx->idx;
 		/* for the first pass, assume the worst case */
 		if (!ctx->image)
 			ctx->idx += 4;
@@ -2994,7 +2997,7 @@ int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,
 		.image = NULL,
 		.idx = 0,
 	};
-	struct bpf_tramp_image im;
+	struct bpf_tramp_image im = {};
 	struct arg_aux aaux;
 	int ret;
 
@@ -3281,6 +3284,10 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t,
 	 *    longer reachable, since bpf_tramp_image_put() function already
 	 *    uses percpu_ref and task-based rcu to do the sync, no need to call
 	 *    the sync version here, see bpf_tramp_image_put() for details.
+	 *
+	 * 3. when a detached prog is patched out of a trampoline, a CPU that
+	 *    still executes the old nop calls the prog before it went through
+	 *    a quiescent state, and the prog is freed after grace periods.
 	 */
 	ret = aarch64_insn_patch_text_nosync(ip, new_insn);
 out:

arch/loongarch/net/bpf_jit.c

View file

diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c
index 4da2789..e78eb58 100644
--- a/arch/loongarch/net/bpf_jit.c
+++ b/arch/loongarch/net/bpf_jit.c
@@ -1578,6 +1578,24 @@ void *bpf_arch_text_copy(void *dst, void *src, size_t len)
 	return ret ? ERR_PTR(-EINVAL) : dst;
 }
 
+int arch_bpf_trampoline_skip(void *nop, void *target)
+{
+	u32 old_insn = INSN_NOP;
+	u32 new_insn = larch_insn_gen_b((unsigned long)nop, (unsigned long)target);
+	int ret;
+
+	if (memcmp(nop, &old_insn, LOONGARCH_INSN_SIZE))
+		return -EFAULT;
+
+	cpus_read_lock();
+	mutex_lock(&text_mutex);
+	ret = larch_insn_text_copy(nop, &new_insn, LOONGARCH_INSN_SIZE);
+	mutex_unlock(&text_mutex);
+	cpus_read_unlock();
+
+	return ret;
+}
+
 int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t,
 		       enum bpf_text_poke_type new_t, void *old_addr,
 		       void *new_addr)
@@ -1696,13 +1714,18 @@ static void restore_stk_args(struct jit_ctx *ctx, int nr_stk_args, int args_off,
 	}
 }
 
-static int invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_node *n,
-			   int args_off, int retval_off, int run_ctx_off, bool save_ret)
+static int invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_image *im,
+			   struct bpf_tramp_node *n, int args_off, int retval_off,
+			   int run_ctx_off, bool save_ret)
 {
 	int ret;
 	u32 *branch;
 	struct bpf_prog *p = n->link->prog;
 	int cookie_off = offsetof(struct bpf_tramp_run_ctx, bpf_cookie);
+	void *skip = ctx->ro_image + ctx->idx;
+
+	/* nop, patched to a b over this prog when it is detached */
+	emit_insn(ctx, nop);
 
 	if (n->cookie)
 		emit_store_stack_imm64(ctx, LOONGARCH_GPR_T1,
@@ -1755,13 +1778,17 @@ static int invoke_bpf_prog(struct jit_ctx *ctx, struct bpf_tramp_node *n,
 	/* arg3: &run_ctx */
 	emit_insn(ctx, addid, LOONGARCH_GPR_A2, LOONGARCH_GPR_FP, -run_ctx_off);
 	ret = emit_call(ctx, (const u64)bpf_trampoline_exit(p));
+	if (ret)
+		return ret;
 
-	return ret;
+	bpf_tramp_image_add_skip(im, p, skip, ctx->ro_image + ctx->idx);
+	return 0;
 }
 
-static int invoke_bpf(struct jit_ctx *ctx, struct bpf_tramp_nodes *tn,
-		      int args_off, int retval_off, int run_ctx_off,
-		      int func_meta_off, bool save_ret, u64 func_meta, int cookie_off)
+static int invoke_bpf(struct jit_ctx *ctx, struct bpf_tramp_image *im,
+		      struct bpf_tramp_nodes *tn, int args_off, int retval_off,
+		      int run_ctx_off, int func_meta_off, bool save_ret,
+		      u64 func_meta, int cookie_off)
 {
 	int i, cur_cookie = (cookie_off - args_off) / 8;
 
@@ -1774,7 +1801,8 @@ static int invoke_bpf(struct jit_ctx *ctx, struct bpf_tramp_nodes *tn,
 			emit_store_stack_imm64(ctx, LOONGARCH_GPR_T1, -func_meta_off, meta);
 			cur_cookie--;
 		}
-		err = invoke_bpf_prog(ctx, tn->nodes[i], args_off, retval_off, run_ctx_off, save_ret);
+		err = invoke_bpf_prog(ctx, im, tn->nodes[i], args_off, retval_off,
+				      run_ctx_off, save_ret);
 		if (err)
 			return err;
 	}
@@ -2017,7 +2045,7 @@ static int __arch_prepare_bpf_trampoline(struct jit_ctx *ctx, struct bpf_tramp_i
 	}
 
 	if (fentry->nr_nodes) {
-		ret = invoke_bpf(ctx, fentry, args_off, retval_off, run_ctx_off, func_meta_off,
+		ret = invoke_bpf(ctx, im, fentry, args_off, retval_off, run_ctx_off, func_meta_off,
 				 flags & BPF_TRAMP_F_RET_FENTRY_RET, func_meta, cookie_off);
 		if (ret)
 			return ret;
@@ -2029,7 +2057,7 @@ static int __arch_prepare_bpf_trampoline(struct jit_ctx *ctx, struct bpf_tramp_i
 
 		emit_insn(ctx, std, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_FP, -retval_off);
 		for (i = 0; i < fmod_ret->nr_nodes; i++) {
-			ret = invoke_bpf_prog(ctx, fmod_ret->nodes[i],
+			ret = invoke_bpf_prog(ctx, im, fmod_ret->nodes[i],
 					      args_off, retval_off, run_ctx_off, true);
 			if (ret)
 				goto out;
@@ -2051,10 +2079,6 @@ static int __arch_prepare_bpf_trampoline(struct jit_ctx *ctx, struct bpf_tramp_i
 			goto out;
 		emit_insn(ctx, std, LOONGARCH_GPR_A0, LOONGARCH_GPR_FP, -retval_off);
 		emit_insn(ctx, std, regmap[BPF_REG_0], LOONGARCH_GPR_FP, -(retval_off - 8));
-		im->ip_after_call = ctx->ro_image + ctx->idx;
-		/* Reserve space for the move_imm + jirl instruction */
-		for (i = 0; i < LOONGARCH_LONG_JUMP_NINSNS; i++)
-			emit_insn(ctx, nop);
 	}
 
 	for (i = 0; ctx->image && i < fmod_ret->nr_nodes; i++) {
@@ -2068,14 +2092,13 @@ static int __arch_prepare_bpf_trampoline(struct jit_ctx *ctx, struct bpf_tramp_i
 		emit_store_stack_imm64(ctx, LOONGARCH_GPR_T1, -func_meta_off, func_meta);
 
 	if (fexit->nr_nodes) {
-		ret = invoke_bpf(ctx, fexit, args_off, retval_off, run_ctx_off,
+		ret = invoke_bpf(ctx, im, fexit, args_off, retval_off, run_ctx_off,
 				 func_meta_off, false, func_meta, cookie_off);
 		if (ret)
 			goto out;
 	}
 
 	if (flags & BPF_TRAMP_F_CALL_ORIG) {
-		im->ip_epilogue = ctx->ro_image + ctx->idx;
 		move_addr(ctx, LOONGARCH_GPR_A0, (const u64)im);
 		ret = emit_call(ctx, (const u64)__bpf_tramp_exit);
 		if (ret)
@@ -2177,11 +2200,8 @@ int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,
 			     struct bpf_tramp_nodes *tnodes, void *func_addr)
 {
 	int ret;
-	struct jit_ctx ctx;
-	struct bpf_tramp_image im;
-
-	ctx.image = NULL;
-	ctx.idx = 0;
+	struct jit_ctx ctx = {};
+	struct bpf_tramp_image im = {};
 
 	ret = __arch_prepare_bpf_trampoline(&ctx, &im, m, tnodes, func_addr, flags);
 

arch/powerpc/net/bpf_jit_comp.c

View file

diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
index 7b07b43..7a61268 100644
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c
@@ -602,14 +602,18 @@ int arch_protect_bpf_trampoline(void *image, unsigned int size)
 }
 
 static int invoke_bpf_prog(u32 *image, u32 *ro_image, struct codegen_context *ctx,
-			   struct bpf_tramp_node *n, int regs_off, int retval_off,
-			   int run_ctx_off, bool save_ret)
+			   struct bpf_tramp_image *im, struct bpf_tramp_node *n,
+			   int regs_off, int retval_off, int run_ctx_off, bool save_ret)
 {
 	struct bpf_prog *p = n->link->prog;
 	ppc_inst_t branch_insn;
-	u32 jmp_idx;
+	u32 jmp_idx, skip_idx;
 	int ret = 0;
 
+	/* nop, patched to skip this prog when it is detached */
+	skip_idx = ctx->idx;
+	EMIT(PPC_RAW_NOP());
+
 	/* Save cookie */
 	if (IS_ENABLED(CONFIG_PPC64)) {
 		PPC_LI64(_R3, n->cookie);
@@ -679,13 +683,17 @@ static int invoke_bpf_prog(u32 *image, u32 *ro_image, struct codegen_context *ct
 	EMIT(PPC_RAW_ADDI(_R5, _R1, run_ctx_off));
 	ret = bpf_jit_emit_func_call_rel(image, ro_image, ctx,
 					 (unsigned long)bpf_trampoline_exit(p));
+	if (ret)
+		return ret;
 
-	return ret;
+	if (ro_image) /* image is NULL for dummy pass */
+		bpf_tramp_image_add_skip(im, p, &ro_image[skip_idx], &ro_image[ctx->idx]);
+	return 0;
 }
 
 static int invoke_bpf_mod_ret(u32 *image, u32 *ro_image, struct codegen_context *ctx,
-			      struct bpf_tramp_nodes *tn, int regs_off, int retval_off,
-			      int run_ctx_off, u32 *branches)
+			      struct bpf_tramp_image *im, struct bpf_tramp_nodes *tn,
+			      int regs_off, int retval_off, int run_ctx_off, u32 *branches)
 {
 	int i;
 
@@ -696,8 +704,8 @@ static int invoke_bpf_mod_ret(u32 *image, u32 *ro_image, struct codegen_context 
 	EMIT(PPC_RAW_LI(_R3, 0));
 	EMIT(PPC_RAW_STL(_R3, _R1, retval_off));
 	for (i = 0; i < tn->nr_nodes; i++) {
-		if (invoke_bpf_prog(image, ro_image, ctx, tn->nodes[i], regs_off, retval_off,
-				    run_ctx_off, true))
+		if (invoke_bpf_prog(image, ro_image, ctx, im, tn->nodes[i], regs_off,
+				    retval_off, run_ctx_off, true))
 			return -EINVAL;
 
 		/*
@@ -1043,8 +1051,8 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *rw_im
 			cookie_ctx_off--;
 		}
 
-		if (invoke_bpf_prog(image, ro_image, ctx, fentry->nodes[i], regs_off, retval_off,
-				    run_ctx_off, flags & BPF_TRAMP_F_RET_FENTRY_RET))
+		if (invoke_bpf_prog(image, ro_image, ctx, im, fentry->nodes[i], regs_off,
+				    retval_off, run_ctx_off, flags & BPF_TRAMP_F_RET_FENTRY_RET))
 			return -EINVAL;
 	}
 
@@ -1053,7 +1061,7 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *rw_im
 		if (!branches)
 			return -ENOMEM;
 
-		if (invoke_bpf_mod_ret(image, ro_image, ctx, fmod_ret, regs_off, retval_off,
+		if (invoke_bpf_mod_ret(image, ro_image, ctx, im, fmod_ret, regs_off, retval_off,
 				       run_ctx_off, branches)) {
 			ret = -EINVAL;
 			goto cleanup;
@@ -1090,11 +1098,6 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *rw_im
 		/* Restore updated tail_call_cnt */
 		if (flags & BPF_TRAMP_F_TAIL_CALL_CTX)
 			bpf_trampoline_restore_tail_call_cnt(image, ctx, bpf_frame_size, r4_off);
-
-		/* Reserve space to patch branch instruction to skip fexit progs */
-		if (ro_image) /* image is NULL for dummy pass */
-			im->ip_after_call = &((u32 *)ro_image)[ctx->idx];
-		EMIT(PPC_RAW_NOP());
 	}
 
 	/* Update branches saved in invoke_bpf_mod_ret with address of do_fexit */
@@ -1123,16 +1126,14 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *rw_im
 			cookie_ctx_off--;
 		}
 
-		if (invoke_bpf_prog(image, ro_image, ctx, fexit->nodes[i], regs_off, retval_off,
-				    run_ctx_off, false)) {
+		if (invoke_bpf_prog(image, ro_image, ctx, im, fexit->nodes[i], regs_off,
+				    retval_off, run_ctx_off, false)) {
 			ret = -EINVAL;
 			goto cleanup;
 		}
 	}
 
 	if (flags & BPF_TRAMP_F_CALL_ORIG) {
-		if (ro_image) /* image is NULL for dummy pass */
-			im->ip_epilogue = &((u32 *)ro_image)[ctx->idx];
 		PPC_LI_ADDR(_R3, im);
 		ret = bpf_jit_emit_func_call_rel(image, ro_image, ctx,
 						 (unsigned long)__bpf_tramp_exit);
@@ -1192,7 +1193,7 @@ cleanup:
 int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,
 			     struct bpf_tramp_nodes *tnodes, void *func_addr)
 {
-	struct bpf_tramp_image im;
+	struct bpf_tramp_image im = {};
 	int ret;
 
 	ret = __arch_prepare_bpf_trampoline(&im, NULL, NULL, NULL, m, flags, tnodes, func_addr);
@@ -1320,7 +1321,7 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t,
 
 	/*
 	 * If we are not poking at bpf prog entry, then we are simply patching in/out
-	 * an unconditional branch instruction at im->ip_after_call
+	 * an unconditional branch instruction in a trampoline image
 	 */
 	if (offset) {
 		if (old_t == BPF_MOD_CALL || new_t == BPF_MOD_CALL) {

arch/riscv/net/bpf_jit_comp64.c

View file

diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c
index 151031e..01fe667 100644
--- a/arch/riscv/net/bpf_jit_comp64.c
+++ b/arch/riscv/net/bpf_jit_comp64.c
@@ -822,6 +822,24 @@ static int gen_jump_or_nops(void *target, void *ip, u32 *insns, bool is_call)
 	return emit_jump_and_link(is_call ? RV_REG_T0 : RV_REG_ZERO, rvoff, false, &ctx);
 }
 
+int arch_bpf_trampoline_skip(void *nop, void *target)
+{
+	u32 old_insn = rv_nop();
+	u32 new_insn = rv_jal(RV_REG_ZERO, (target - nop) >> 1);
+	int ret;
+
+	if (memcmp(nop, &old_insn, sizeof(old_insn)))
+		return -EFAULT;
+
+	cpus_read_lock();
+	mutex_lock(&text_mutex);
+	ret = patch_text(nop, &new_insn, sizeof(new_insn));
+	mutex_unlock(&text_mutex);
+	cpus_read_unlock();
+
+	return ret;
+}
+
 int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t,
 		       enum bpf_text_poke_type new_t, void *old_addr,
 		       void *new_addr)
@@ -904,12 +922,17 @@ static void emit_store_stack_imm64(u8 reg, int stack_off, u64 imm64,
 	emit_sd(RV_REG_FP, stack_off, reg, ctx);
 }
 
-static int invoke_bpf_prog(struct bpf_tramp_node *node, int args_off, int retval_off,
-			   int run_ctx_off, bool save_ret, struct rv_jit_context *ctx)
+static int invoke_bpf_prog(struct bpf_tramp_image *im, struct bpf_tramp_node *node,
+			   int args_off, int retval_off, int run_ctx_off, bool save_ret,
+			   struct rv_jit_context *ctx)
 {
 	int ret, branch_off;
 	struct bpf_prog *p = node->link->prog;
 	int cookie_off = offsetof(struct bpf_tramp_run_ctx, bpf_cookie);
+	void *skip = ctx->ro_insns + ctx->ninsns;
+
+	/* nop, patched to a jal over this prog when it is detached */
+	emit(rv_nop(), ctx);
 
 	if (node->cookie)
 		emit_store_stack_imm64(RV_REG_T1, -run_ctx_off + cookie_off, node->cookie, ctx);
@@ -962,13 +985,17 @@ static int invoke_bpf_prog(struct bpf_tramp_node *node, int args_off, int retval
 	/* arg3: &run_ctx */
 	emit_addi(RV_REG_A2, RV_REG_FP, -run_ctx_off, ctx);
 	ret = emit_call((const u64)bpf_trampoline_exit(p), true, ctx);
+	if (ret)
+		return ret;
 
-	return ret;
+	bpf_tramp_image_add_skip(im, p, skip, ctx->ro_insns + ctx->ninsns);
+	return 0;
 }
 
-static int invoke_bpf(struct bpf_tramp_nodes *tn, int args_off, int retval_off,
-		      int run_ctx_off, int func_meta_off, bool save_ret, u64 func_meta,
-		      int cookie_off, struct rv_jit_context *ctx)
+static int invoke_bpf(struct bpf_tramp_image *im, struct bpf_tramp_nodes *tn,
+		      int args_off, int retval_off, int run_ctx_off, int func_meta_off,
+		      bool save_ret, u64 func_meta, int cookie_off,
+		      struct rv_jit_context *ctx)
 {
 	int i, cur_cookie = (cookie_off - args_off) / 8;
 
@@ -981,8 +1008,8 @@ static int invoke_bpf(struct bpf_tramp_nodes *tn, int args_off, int retval_off,
 			emit_store_stack_imm64(RV_REG_T1, -func_meta_off, meta, ctx);
 			cur_cookie--;
 		}
-		err = invoke_bpf_prog(tn->nodes[i], args_off, retval_off, run_ctx_off,
-				      save_ret, ctx);
+		err = invoke_bpf_prog(im, tn->nodes[i], args_off, retval_off,
+				      run_ctx_off, save_ret, ctx);
 		if (err)
 			return err;
 	}
@@ -1170,7 +1197,7 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im,
 	}
 
 	if (fentry->nr_nodes) {
-		ret = invoke_bpf(fentry, args_off, retval_off, run_ctx_off, func_meta_off,
+		ret = invoke_bpf(im, fentry, args_off, retval_off, run_ctx_off, func_meta_off,
 				 flags & BPF_TRAMP_F_RET_FENTRY_RET, func_meta, cookie_off, ctx);
 		if (ret)
 			return ret;
@@ -1184,7 +1211,7 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im,
 		/* cleanup to avoid garbage return value confusion */
 		emit_sd(RV_REG_FP, -retval_off, RV_REG_ZERO, ctx);
 		for (i = 0; i < fmod_ret->nr_nodes; i++) {
-			ret = invoke_bpf_prog(fmod_ret->nodes[i], args_off, retval_off,
+			ret = invoke_bpf_prog(im, fmod_ret->nodes[i], args_off, retval_off,
 					      run_ctx_off, true, ctx);
 			if (ret)
 				goto out;
@@ -1211,10 +1238,6 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im,
 			emit_sd(RV_REG_FP, -tcc_off, RV_REG_TCC, ctx);
 		emit_sd(RV_REG_FP, -retval_off, RV_REG_A0, ctx);
 		emit_sd(RV_REG_FP, -(retval_off - 8), regmap[BPF_REG_0], ctx);
-		im->ip_after_call = ctx->ro_insns + ctx->ninsns;
-		/* 2 nops reserved for auipc+jalr pair */
-		emit(rv_nop(), ctx);
-		emit(rv_nop(), ctx);
 	}
 
 	/* update branches saved in invoke_bpf_mod_ret with bnez */
@@ -1230,14 +1253,13 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im,
 		emit_store_stack_imm64(RV_REG_T1, -func_meta_off, func_meta, ctx);
 
 	if (fexit->nr_nodes) {
-		ret = invoke_bpf(fexit, args_off, retval_off, run_ctx_off, func_meta_off,
+		ret = invoke_bpf(im, fexit, args_off, retval_off, run_ctx_off, func_meta_off,
 				 false, func_meta, cookie_off, ctx);
 		if (ret)
 			goto out;
 	}
 
 	if (flags & BPF_TRAMP_F_CALL_ORIG) {
-		im->ip_epilogue = ctx->ro_insns + ctx->ninsns;
 		emit_imm(RV_REG_A0, ctx->insns ? (const s64)im : RV_MAX_COUNT_IMM, ctx);
 		ret = emit_call((const u64)__bpf_tramp_exit, true, ctx);
 		if (ret)
@@ -1299,7 +1321,7 @@ out:
 int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,
 			     struct bpf_tramp_nodes *tnodes, void *func_addr)
 {
-	struct bpf_tramp_image im;
+	struct bpf_tramp_image im = {};
 	struct rv_jit_context ctx;
 	int ret;
 

arch/s390/net/bpf_jit_comp.c

View file

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index c4b4707..1b25660 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -2566,6 +2566,8 @@ struct bpf_tramp_jit {
 	int r14_off;		/* Offset of saved %r14, has to be at the
 				 * bottom */
 	int do_fexit;		/* do_fexit: label */
+	int skip[BPF_MAX_TRAMP_LINKS];	/* skip: labels after each prog */
+	int nr_progs;
 };
 
 static void load_imm64(struct bpf_jit *jit, int dst_reg, u64 val)
@@ -2584,6 +2586,7 @@ static void emit_store_stack_imm64(struct bpf_jit *jit, int tmp_reg, int stack_o
 }
 
 static int invoke_bpf_prog(struct bpf_tramp_jit *tjit,
+			   struct bpf_tramp_image *im,
 			   const struct btf_func_model *m,
 			   struct bpf_tramp_node *node, bool save_ret)
 {
@@ -2591,8 +2594,20 @@ static int invoke_bpf_prog(struct bpf_tramp_jit *tjit,
 	int cookie_off = tjit->run_ctx_off +
 			 offsetof(struct bpf_tramp_run_ctx, bpf_cookie);
 	struct bpf_prog *p = node->link->prog;
+	void *skip = jit->prg_buf + jit->prg;
+	int idx = tjit->nr_progs++;
 	int patch;
 
+	if (idx >= ARRAY_SIZE(tjit->skip))
+		return -E2BIG;
+
+	/*
+	 * nop, patched to skip this prog when it is detached
+	 */
+
+	/* brcl 0,skip */
+	EMIT6_PCREL_RILC(0xc0040000, 0, tjit->skip[idx]);
+
 	/*
 	 * run_ctx.cookie = node->cookie;
 	 */
@@ -2652,10 +2667,15 @@ static int invoke_bpf_prog(struct bpf_tramp_jit *tjit,
 	/* brasl %r14,__bpf_prog_exit */
 	EMIT6_PCREL_RILB_PTR(0xc0050000, REG_14, bpf_trampoline_exit(p));
 
+	/* skip: */
+	tjit->skip[idx] = jit->prg;
+	bpf_tramp_image_add_skip(im, p, skip, jit->prg_buf + jit->prg);
+
 	return 0;
 }
 
 static int invoke_bpf(struct bpf_tramp_jit *tjit,
+		      struct bpf_tramp_image *im,
 		      const struct btf_func_model *m,
 		      struct bpf_tramp_nodes *tn, bool save_ret,
 		      u64 func_meta, int cookie_off)
@@ -2670,7 +2690,7 @@ static int invoke_bpf(struct bpf_tramp_jit *tjit,
 			emit_store_stack_imm64(jit, REG_0, tjit->func_meta_off, meta);
 			cur_cookie--;
 		}
-		if (invoke_bpf_prog(tjit, m, tn->nodes[i], save_ret))
+		if (invoke_bpf_prog(tjit, im, m, tn->nodes[i], save_ret))
 			return -EINVAL;
 	}
 
@@ -2712,6 +2732,11 @@ static int __arch_prepare_bpf_trampoline(struct bpf_tramp_image *im,
 	u64 func_meta;
 	int i, j;
 
+	/* The skip labels are taken from the previous pass. */
+	tjit->nr_progs = 0;
+	if (im)
+		im->nr_skips = 0;
+
 	/* Support as many stack arguments as "mvc" instruction can handle. */
 	nr_reg_args = min_t(int, m->nr_args, MAX_NR_REG_ARGS);