kernel-patches · kernel-patches-daemon-bpf · Dec 12, 2025 · Dec 12, 2025 · Dec 12, 2025 · Dec 12, 2025
diff --git a/arch/loongarch/kernel/mcount_dyn.S b/arch/loongarch/kernel/mcount_dyn.S
@@ -94,7 +94,6 @@ SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL)
  * at the callsite, so there is no need to restore the T series regs.
  */
 ftrace_common_return:
-	PTR_L		ra, sp, PT_R1
 	PTR_L		a0, sp, PT_R4
 	PTR_L		a1, sp, PT_R5
 	PTR_L		a2, sp, PT_R6
@@ -104,12 +103,17 @@ ftrace_common_return:
 	PTR_L		a6, sp, PT_R10
 	PTR_L		a7, sp, PT_R11
 	PTR_L		fp, sp, PT_R22
-	PTR_L		t0, sp, PT_ERA
 	PTR_L		t1, sp, PT_R13
-	PTR_ADDI	sp, sp, PT_SIZE
 	bnez		t1, .Ldirect
+
+	PTR_L		ra, sp, PT_R1
+	PTR_L		t0, sp, PT_ERA
+	PTR_ADDI	sp, sp, PT_SIZE
 	jr		t0
 .Ldirect:
+	PTR_L		t0, sp, PT_R1
+	PTR_L		ra, sp, PT_ERA
+	PTR_ADDI	sp, sp, PT_SIZE
 	jr		t1
 SYM_CODE_END(ftrace_common)
 
@@ -161,6 +165,8 @@ SYM_CODE_END(return_to_handler)
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
 SYM_CODE_START(ftrace_stub_direct_tramp)
 	UNWIND_HINT_UNDEFINED
-	jr		t0
+	move		t1, ra
+	move		ra, t0
+	jr		t1
 SYM_CODE_END(ftrace_stub_direct_tramp)
 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
diff --git a/arch/loongarch/kernel/traps.c b/arch/loongarch/kernel/traps.c
@@ -534,7 +534,13 @@ asmlinkage void noinstr do_fpe(struct pt_regs *regs, unsigned long fcsr)
 
 asmlinkage void noinstr do_ade(struct pt_regs *regs)
 {
-	irqentry_state_t state = irqentry_enter(regs);
+	irqentry_state_t state;
+	unsigned int esubcode = FIELD_GET(CSR_ESTAT_ESUBCODE, regs->csr_estat);
+
+	if ((esubcode == EXSUBCODE_ADEM) && fixup_exception(regs))
+		return;
+
+	state = irqentry_enter(regs);
 
 	die_if_kernel("Kernel ade access", regs);
 	force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)regs->csr_badvaddr);

diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c
@@ -139,6 +139,7 @@ static void build_prologue(struct jit_ctx *ctx)
 	stack_adjust = round_up(stack_adjust, 16);
 	stack_adjust += bpf_stack_adjust;
 
+	move_reg(ctx, LOONGARCH_GPR_T0, LOONGARCH_GPR_RA);
 	/* Reserve space for the move_imm + jirl instruction */
 	for (i = 0; i < LOONGARCH_LONG_JUMP_NINSNS; i++)
 		emit_insn(ctx, nop);
@@ -238,7 +239,7 @@ static void __build_epilogue(struct jit_ctx *ctx, bool is_tail_call)
 		 * Call the next bpf prog and skip the first instruction
 		 * of TCC initialization.
 		 */
-		emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T3, 6);
+		emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T3, 7);
 	}
 }
 
@@ -1265,7 +1266,7 @@ static int emit_jump_or_nops(void *target, void *ip, u32 *insns, bool is_call)
 		return 0;
 	}
 
-	return emit_jump_and_link(&ctx, is_call ? LOONGARCH_GPR_T0 : LOONGARCH_GPR_ZERO, (u64)target);
+	return emit_jump_and_link(&ctx, is_call ? LOONGARCH_GPR_RA : LOONGARCH_GPR_ZERO, (u64)target);
 }
 
 static int emit_call(struct jit_ctx *ctx, u64 addr)
@@ -1289,16 +1290,29 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type old_t,
 		       void *new_addr)
 {
 	int ret;
+	unsigned long size = 0;
+	unsigned long offset = 0;
+	char namebuf[KSYM_NAME_LEN];
+	void *image = NULL;
 	bool is_call;
 	u32 old_insns[LOONGARCH_LONG_JUMP_NINSNS] = {[0 ... 4] = INSN_NOP};
 	u32 new_insns[LOONGARCH_LONG_JUMP_NINSNS] = {[0 ... 4] = INSN_NOP};
 
 	/* Only poking bpf text is supported. Since kernel function entry
 	 * is set up by ftrace, we rely on ftrace to poke kernel functions.
 	 */
-	if (!is_bpf_text_address((unsigned long)ip))
+	if (!__bpf_address_lookup((unsigned long)ip, &size, &offset, namebuf))
 		return -ENOTSUPP;
 
+	image = ip - offset;
+	/* zero offset means we're poking bpf prog entry */
+	if (offset == 0)
+		/* skip to the nop instruction in bpf prog entry:
+		 * move t0, ra
+		 * nop
+		 */
+		ip = image + LOONGARCH_INSN_SIZE;
+
 	is_call = old_t == BPF_MOD_CALL;
 	ret = emit_jump_or_nops(old_addr, ip, old_insns, is_call);
 	if (ret)
@@ -1622,14 +1636,12 @@ static int __arch_prepare_bpf_trampoline(struct jit_ctx *ctx, struct bpf_tramp_i
 
 	/* To traced function */
 	/* Ftrace jump skips 2 NOP instructions */
-	if (is_kernel_text((unsigned long)orig_call))
+	if (is_kernel_text((unsigned long)orig_call) ||
+	    is_module_text_address((unsigned long)orig_call))
 		orig_call += LOONGARCH_FENTRY_NBYTES;
 	/* Direct jump skips 5 NOP instructions */
 	else if (is_bpf_text_address((unsigned long)orig_call))
 		orig_call += LOONGARCH_BPF_FENTRY_NBYTES;
-	/* Module tracing not supported - cause kernel lockups */
-	else if (is_module_text_address((unsigned long)orig_call))
-		return -ENOTSUPP;
 
 	if (flags & BPF_TRAMP_F_CALL_ORIG) {
 		move_addr(ctx, LOONGARCH_GPR_A0, (const u64)im);
@@ -1722,12 +1734,16 @@ static int __arch_prepare_bpf_trampoline(struct jit_ctx *ctx, struct bpf_tramp_i
 		emit_insn(ctx, ldd, LOONGARCH_GPR_FP, LOONGARCH_GPR_SP, 0);
 		emit_insn(ctx, addid, LOONGARCH_GPR_SP, LOONGARCH_GPR_SP, 16);
 
-		if (flags & BPF_TRAMP_F_SKIP_FRAME)
+		if (flags & BPF_TRAMP_F_SKIP_FRAME) {
 			/* return to parent function */
-			emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_RA, 0);
-		else
-			/* return to traced function */
+			move_reg(ctx, LOONGARCH_GPR_RA, LOONGARCH_GPR_T0);
 			emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T0, 0);
+		} else {
+			/* return to traced function */
+			move_reg(ctx, LOONGARCH_GPR_T1, LOONGARCH_GPR_RA);
+			move_reg(ctx, LOONGARCH_GPR_RA, LOONGARCH_GPR_T0);
+			emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T1, 0);
+		}
 	}
 
 	ret = ctx->idx;

diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
@@ -176,8 +176,8 @@ asm (
 "	st.d	$t0, $sp, 0\n"
 "	st.d	$ra, $sp, 8\n"
 "	bl	my_direct_func1\n"
-"	ld.d	$t0, $sp, 0\n"
-"	ld.d	$ra, $sp, 8\n"
+"	ld.d	$ra, $sp, 0\n"
+"	ld.d	$t0, $sp, 8\n"
 "	addi.d	$sp, $sp, 16\n"
 "	jr	$t0\n"
 "	.size		my_tramp1, .-my_tramp1\n"
@@ -189,8 +189,8 @@ asm (
 "	st.d	$t0, $sp, 0\n"
 "	st.d	$ra, $sp, 8\n"
 "	bl	my_direct_func2\n"
-"	ld.d	$t0, $sp, 0\n"
-"	ld.d	$ra, $sp, 8\n"
+"	ld.d	$ra, $sp, 0\n"
+"	ld.d	$t0, $sp, 8\n"
 "	addi.d	$sp, $sp, 16\n"
 "	jr	$t0\n"
 "	.size		my_tramp2, .-my_tramp2\n"

diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c
@@ -199,8 +199,8 @@ asm (
 "	move	$a0, $t0\n"
 "	bl	my_direct_func1\n"
 "	ld.d	$a0, $sp, 0\n"
-"	ld.d	$t0, $sp, 8\n"
-"	ld.d	$ra, $sp, 16\n"
+"	ld.d	$ra, $sp, 8\n"
+"	ld.d	$t0, $sp, 16\n"
 "	addi.d	$sp, $sp, 32\n"
 "	jr	$t0\n"
 "	.size		my_tramp1, .-my_tramp1\n"
@@ -215,8 +215,8 @@ asm (
 "	move	$a0, $t0\n"
 "	bl	my_direct_func2\n"
 "	ld.d	$a0, $sp, 0\n"
-"	ld.d	$t0, $sp, 8\n"
-"	ld.d	$ra, $sp, 16\n"
+"	ld.d	$ra, $sp, 8\n"
+"	ld.d	$t0, $sp, 16\n"
 "	addi.d	$sp, $sp, 32\n"
 "	jr	$t0\n"
 "	.size		my_tramp2, .-my_tramp2\n"

diff --git a/samples/ftrace/ftrace-direct-multi.c b/samples/ftrace/ftrace-direct-multi.c
@@ -131,8 +131,8 @@ asm (
 "	move	$a0, $t0\n"
 "	bl	my_direct_func\n"
 "	ld.d	$a0, $sp, 0\n"
-"	ld.d	$t0, $sp, 8\n"
-"	ld.d	$ra, $sp, 16\n"
+"	ld.d	$ra, $sp, 8\n"
+"	ld.d	$t0, $sp, 16\n"
 "	addi.d	$sp, $sp, 32\n"
 "	jr	$t0\n"
 "	.size		my_tramp, .-my_tramp\n"

diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
@@ -143,8 +143,8 @@ asm (
 "	ld.d	$a0, $sp, 0\n"
 "	ld.d	$a1, $sp, 8\n"
 "	ld.d	$a2, $sp, 16\n"
-"	ld.d	$t0, $sp, 24\n"
-"	ld.d	$ra, $sp, 32\n"
+"	ld.d	$ra, $sp, 24\n"
+"	ld.d	$t0, $sp, 32\n"
 "	addi.d	$sp, $sp, 48\n"
 "	jr	$t0\n"
 "	.size		my_tramp, .-my_tramp\n"

diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c
@@ -124,8 +124,8 @@ asm (
 "	st.d	$ra, $sp, 16\n"
 "	bl	my_direct_func\n"
 "	ld.d	$a0, $sp, 0\n"
-"	ld.d	$t0, $sp, 8\n"
-"	ld.d	$ra, $sp, 16\n"
+"	ld.d	$ra, $sp, 8\n"
+"	ld.d	$t0, $sp, 16\n"
 "	addi.d	$sp, $sp, 32\n"
 "	jr	$t0\n"
 "	.size		my_tramp, .-my_tramp\n"