Merge tag 'riscv-for-linus-6.18-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Paul Walmsley:

 - A fix to disable KASAN checks while walking a non-current task's
   stackframe (following x86)

 - A fix for a kvrealloc()-related memory leak in
   module_frob_arch_sections()

 - Two replacements of strcpy() with strscpy()

 - A change to use the RISC-V .insn assembler directive when possible to
   assemble instructions from hex opcodes

 - Some low-impact fixes in the ptdump code and kprobes test code

* tag 'riscv-for-linus-6.18-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  cpuidle: riscv-sbi: Replace deprecated strcpy in sbi_cpuidle_init_cpu
  riscv: KGDB: Replace deprecated strcpy in kgdb_arch_handle_qxfer_pkt
  riscv: asm: use .insn for making custom instructions
  riscv: tests: Make RISCV_KPROBES_KUNIT tristate
  riscv: tests: Rename kprobes_test_riscv to kprobes_riscv
  riscv: Fix memory leak in module_frob_arch_sections()
  riscv: ptdump: use seq_puts() in pt_dump_seq_puts() macro
  riscv: stacktrace: Disable KASAN checks for non-current tasks

Author: torvalds

arch/riscv/include/asm/asm.h

@@ -12,6 +12,12 @@
 #define __ASM_STR(x)	#x
 #endif
 
+#ifdef CONFIG_AS_HAS_INSN
+#define ASM_INSN_I(__x) ".insn " __x
+#else
+#define ASM_INSN_I(__x) ".4byte " __x
+#endif
+
 #if __riscv_xlen == 64
 #define __REG_SEL(a, b)	__ASM_STR(a)
 #elif __riscv_xlen == 32

arch/riscv/include/asm/insn-def.h

@@ -256,10 +256,10 @@
 	INSN_S(OPCODE_OP_IMM, FUNC3(6), __RS2(3),		\
 	       SIMM12((offset) & 0xfe0), RS1(base))
 
-#define RISCV_PAUSE	".4byte 0x100000f"
-#define ZAWRS_WRS_NTO	".4byte 0x00d00073"
-#define ZAWRS_WRS_STO	".4byte 0x01d00073"
-#define RISCV_NOP4	".4byte 0x00000013"
+#define RISCV_PAUSE	ASM_INSN_I("0x100000f")
+#define ZAWRS_WRS_NTO	ASM_INSN_I("0x00d00073")
+#define ZAWRS_WRS_STO	ASM_INSN_I("0x01d00073")
+#define RISCV_NOP4	ASM_INSN_I("0x00000013")
 
 #define RISCV_INSN_NOP4	_AC(0x00000013, U)
 

arch/riscv/include/asm/vendor_extensions/mips.h

@@ -30,8 +30,8 @@ extern struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_mips;
  * allowing any subsequent instructions to fetch.
  */
 
-#define MIPS_PAUSE	".4byte 0x00501013\n\t"
-#define MIPS_EHB	".4byte 0x00301013\n\t"
-#define MIPS_IHB	".4byte 0x00101013\n\t"
+#define MIPS_PAUSE	ASM_INSN_I("0x00501013\n\t")
+#define MIPS_EHB	ASM_INSN_I("0x00301013\n\t")
+#define MIPS_IHB	ASM_INSN_I("0x00101013\n\t")
 
 #endif // _ASM_RISCV_VENDOR_EXTENSIONS_MIPS_H

arch/riscv/kernel/kgdb.c

@@ -265,10 +265,10 @@ void kgdb_arch_handle_qxfer_pkt(char *remcom_in_buffer,
 {
 	if (!strncmp(remcom_in_buffer, gdb_xfer_read_target,
 		     sizeof(gdb_xfer_read_target)))
-		strcpy(remcom_out_buffer, riscv_gdb_stub_target_desc);
+		strscpy(remcom_out_buffer, riscv_gdb_stub_target_desc, BUFMAX);
 	else if (!strncmp(remcom_in_buffer, gdb_xfer_read_cpuxml,
 			  sizeof(gdb_xfer_read_cpuxml)))
-		strcpy(remcom_out_buffer, riscv_gdb_stub_cpuxml);
+		strscpy(remcom_out_buffer, riscv_gdb_stub_cpuxml, BUFMAX);
 }
 
 static inline void kgdb_arch_update_addr(struct pt_regs *regs,

arch/riscv/kernel/module-sections.c

@@ -119,6 +119,7 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
 	unsigned int num_plts = 0;
 	unsigned int num_gots = 0;
 	Elf_Rela *scratch = NULL;
+	Elf_Rela *new_scratch;
 	size_t scratch_size = 0;
 	int i;
 
@@ -168,9 +169,12 @@ int module_frob_arch_sections(Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
 		scratch_size_needed = (num_scratch_relas + num_relas) * sizeof(*scratch);
 		if (scratch_size_needed > scratch_size) {
 			scratch_size = scratch_size_needed;
-			scratch = kvrealloc(scratch, scratch_size, GFP_KERNEL);
-			if (!scratch)
+			new_scratch = kvrealloc(scratch, scratch_size, GFP_KERNEL);
+			if (!new_scratch) {
+				kvfree(scratch);
 				return -ENOMEM;
+			}
+			scratch = new_scratch;
 		}
 
 		for (size_t j = 0; j < num_relas; j++)

arch/riscv/kernel/stacktrace.c

@@ -16,6 +16,22 @@
 
 #ifdef CONFIG_FRAME_POINTER
 
+/*
+ * This disables KASAN checking when reading a value from another task's stack,
+ * since the other task could be running on another CPU and could have poisoned
+ * the stack in the meantime.
+ */
+#define READ_ONCE_TASK_STACK(task, x)			\
+({							\
+	unsigned long val;				\
+	unsigned long addr = x;				\
+	if ((task) == current)				\
+		val = READ_ONCE(addr);			\
+	else						\
+		val = READ_ONCE_NOCHECK(addr);		\
+	val;						\
+})
+
 extern asmlinkage void handle_exception(void);
 extern unsigned long ret_from_exception_end;
 
@@ -69,8 +85,9 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
 			fp = frame->ra;
 			pc = regs->ra;
 		} else {
-			fp = frame->fp;
-			pc = ftrace_graph_ret_addr(current, &graph_idx, frame->ra,
+			fp = READ_ONCE_TASK_STACK(task, frame->fp);
+			pc = READ_ONCE_TASK_STACK(task, frame->ra);
+			pc = ftrace_graph_ret_addr(current, &graph_idx, pc,
 						   &frame->ra);
 			if (pc >= (unsigned long)handle_exception &&
 			    pc < (unsigned long)&ret_from_exception_end) {

arch/riscv/kernel/tests/Kconfig.debug

@@ -31,7 +31,7 @@ config RISCV_MODULE_LINKING_KUNIT
          If unsure, say N.
 
 config RISCV_KPROBES_KUNIT
-       bool "KUnit test for riscv kprobes" if !KUNIT_ALL_TESTS
+       tristate "KUnit test for riscv kprobes" if !KUNIT_ALL_TESTS
        depends on KUNIT
        depends on KPROBES
        default KUNIT_ALL_TESTS

arch/riscv/kernel/tests/kprobes/Makefile

@@ -1 +1,3 @@
-obj-y += test-kprobes.o test-kprobes-asm.o
+obj-$(CONFIG_RISCV_KPROBES_KUNIT) += kprobes_riscv_kunit.o
+
+kprobes_riscv_kunit-objs := test-kprobes.o test-kprobes-asm.o

arch/riscv/kernel/tests/kprobes/test-kprobes.c

@@ -49,8 +49,11 @@ static struct kunit_case kprobes_testcases[] = {
 };
 
 static struct kunit_suite kprobes_test_suite = {
-	.name = "kprobes_test_riscv",
+	.name = "kprobes_riscv",
 	.test_cases = kprobes_testcases,
 };
 
 kunit_test_suites(&kprobes_test_suite);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("KUnit test for riscv kprobes");

arch/riscv/mm/ptdump.c

@@ -21,7 +21,7 @@
 #define pt_dump_seq_puts(m, fmt)	\
 ({					\
 	if (m)				\
-		seq_printf(m, fmt);	\
+		seq_puts(m, fmt);	\
 })
 
 /*