Merge tag 'loongarch-fixes-6.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch fixes from Huacai Chen:
 "Preserve syscall nr across execve(), slightly clean up drdtime(), fix
  the Clang built zboot kernel, fix a stack unwinder bug and several bpf
  jit bugs"

* tag 'loongarch-fixes-6.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: BPF: Fix unconditional bswap instructions
  LoongArch: BPF: Fix sign-extension mov instructions
  LoongArch: BPF: Don't sign extend function return value
  LoongArch: BPF: Don't sign extend memory load operand
  LoongArch: Preserve syscall nr across execve()
  LoongArch: Set unwind stack type to unknown rather than set error flag
  LoongArch: Slightly clean up drdtime()
  LoongArch: Apply dynamic relocations for LLD

Author: torvalds

arch/loongarch/Makefile

@@ -83,7 +83,7 @@ endif
 
 ifeq ($(CONFIG_RELOCATABLE),y)
 KBUILD_CFLAGS_KERNEL		+= -fPIE
-LDFLAGS_vmlinux			+= -static -pie --no-dynamic-linker -z notext
+LDFLAGS_vmlinux			+= -static -pie --no-dynamic-linker -z notext $(call ld-option, --apply-dynamic-relocs)
 endif
 
 cflags-y += $(call cc-option, -mno-check-zero-division)

arch/loongarch/include/asm/elf.h

@@ -293,7 +293,7 @@ extern const char *__elf_platform;
 #define ELF_PLAT_INIT(_r, load_addr)	do { \
 	_r->regs[1] = _r->regs[2] = _r->regs[3] = _r->regs[4] = 0;	\
 	_r->regs[5] = _r->regs[6] = _r->regs[7] = _r->regs[8] = 0;	\
-	_r->regs[9] = _r->regs[10] = _r->regs[11] = _r->regs[12] = 0;	\
+	_r->regs[9] = _r->regs[10] /* syscall n */ = _r->regs[12] = 0;	\
 	_r->regs[13] = _r->regs[14] = _r->regs[15] = _r->regs[16] = 0;	\
 	_r->regs[17] = _r->regs[18] = _r->regs[19] = _r->regs[20] = 0;	\
 	_r->regs[21] = _r->regs[22] = _r->regs[23] = _r->regs[24] = 0;	\

arch/loongarch/include/asm/loongarch.h

@@ -1098,12 +1098,11 @@
 
 static __always_inline u64 drdtime(void)
 {
-	int rID = 0;
 	u64 val = 0;
 
 	__asm__ __volatile__(
-		"rdtime.d %0, %1 \n\t"
-		: "=r"(val), "=r"(rID)
+		"rdtime.d %0, $zero\n\t"
+		: "=r"(val)
 		:
 		);
 	return val;

arch/loongarch/kernel/stacktrace.c

@@ -32,7 +32,7 @@ void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
 	}
 
 	for (unwind_start(&state, task, regs);
-	     !unwind_done(&state) && !unwind_error(&state); unwind_next_frame(&state)) {
+	     !unwind_done(&state); unwind_next_frame(&state)) {
 		addr = unwind_get_return_address(&state);
 		if (!addr || !consume_entry(cookie, addr))
 			break;

arch/loongarch/kernel/unwind.c

@@ -28,6 +28,5 @@ bool default_next_frame(struct unwind_state *state)
 
 	} while (!get_stack_info(state->sp, state->task, info));
 
-	state->error = true;
 	return false;
 }

arch/loongarch/kernel/unwind_prologue.c

@@ -227,7 +227,7 @@ static bool next_frame(struct unwind_state *state)
 	} while (!get_stack_info(state->sp, state->task, info));
 
 out:
-	state->error = true;
+	state->stack_info.type = STACK_TYPE_UNKNOWN;
 	return false;
 }
 

arch/loongarch/net/bpf_jit.c

@@ -480,10 +480,12 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
 		case 8:
 			move_reg(ctx, t1, src);
 			emit_insn(ctx, extwb, dst, t1);
+			emit_zext_32(ctx, dst, is32);
 			break;
 		case 16:
 			move_reg(ctx, t1, src);
 			emit_insn(ctx, extwh, dst, t1);
+			emit_zext_32(ctx, dst, is32);
 			break;
 		case 32:
 			emit_insn(ctx, addw, dst, src, LOONGARCH_GPR_ZERO);
@@ -772,8 +774,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
 			break;
 		case 32:
 			emit_insn(ctx, revb2w, dst, dst);
-			/* zero-extend 32 bits into 64 bits */
-			emit_zext_32(ctx, dst, is32);
+			/* clear the upper 32 bits */
+			emit_zext_32(ctx, dst, true);
 			break;
 		case 64:
 			emit_insn(ctx, revbd, dst, dst);
@@ -911,8 +913,6 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
 
 	/* function return */
 	case BPF_JMP | BPF_EXIT:
-		emit_sext_32(ctx, regmap[BPF_REG_0], true);
-
 		if (i == ctx->prog->len - 1)
 			break;
 
@@ -988,14 +988,8 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx, bool ext
 			}
 			break;
 		case BPF_DW:
-			if (is_signed_imm12(off)) {
-				emit_insn(ctx, ldd, dst, src, off);
-			} else if (is_signed_imm14(off)) {
-				emit_insn(ctx, ldptrd, dst, src, off);
-			} else {
-				move_imm(ctx, t1, off, is32);
-				emit_insn(ctx, ldxd, dst, src, t1);
-			}
+			move_imm(ctx, t1, off, is32);
+			emit_insn(ctx, ldxd, dst, src, t1);
 			break;
 		}