Merge tag 'riscv-for-linux-6.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V fixes from Paul Walmsley:

 - Disable CFI with Rust for any platform other than x86 and ARM64

 - Keep task mm_cpumasks up-to-date to avoid triggering M-mode firmware
   warnings if the kernel tries to send an IPI to an offline CPU

 - Improve kprobe address validation performance and avoid desyncs
   (following x86)

 - Avoid duplicate device probes by avoiding DT hardware probing when
   ACPI is enabled in early boot

 - Use the correct set of dependencies for
   CONFIG_ARCH_HAS_ELF_CORE_EFLAGS, avoiding an allnoconfig warning

 - Fix a few other minor issues

* tag 'riscv-for-linux-6.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: kprobes: convert one final __ASSEMBLY__ to __ASSEMBLER__
  riscv: Respect dependencies of ARCH_HAS_ELF_CORE_EFLAGS
  riscv: acpi: avoid errors caused by probing DT devices when ACPI is used
  riscv: kprobes: Fix probe address validation
  riscv: entry: fix typo in comment 'instruciton' -> 'instruction'
  RISC-V: clear hot-unplugged cores from all task mm_cpumasks to avoid rfence errors
  riscv: kgdb: Ensure that BUFMAX > NUMREGBYTES
  rust: cfi: only 64-bit arm and x86 support CFI_CLANG

Author: torvalds

arch/Kconfig

@@ -965,6 +965,7 @@ config HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
 	def_bool y
 	depends on HAVE_CFI_ICALL_NORMALIZE_INTEGERS
 	depends on RUSTC_VERSION >= 107900
+	depends on ARM64 || X86_64
 	# With GCOV/KASAN we need this fix: https://github.com/rust-lang/rust/pull/129373
 	depends on (RUSTC_LLVM_VERSION >= 190103 && RUSTC_VERSION >= 108200) || \
 		(!GCOV_KERNEL && !KASAN_GENERIC && !KASAN_SW_TAGS)

arch/riscv/Kconfig

@@ -29,7 +29,7 @@ config RISCV
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
 	select ARCH_HAS_DEBUG_VM_PGTABLE
 	select ARCH_HAS_DEBUG_WX
-	select ARCH_HAS_ELF_CORE_EFLAGS
+	select ARCH_HAS_ELF_CORE_EFLAGS if BINFMT_ELF && ELF_CORE
 	select ARCH_HAS_FAST_MULTIPLIER
 	select ARCH_HAS_FORTIFY_SOURCE
 	select ARCH_HAS_GCOV_PROFILE_ALL

arch/riscv/include/asm/kgdb.h

@@ -3,14 +3,18 @@
 #ifndef __ASM_KGDB_H_
 #define __ASM_KGDB_H_
 
+#include <linux/build_bug.h>
+
 #ifdef __KERNEL__
 
 #define GDB_SIZEOF_REG sizeof(unsigned long)
 
-#define DBG_MAX_REG_NUM (36)
-#define NUMREGBYTES ((DBG_MAX_REG_NUM) * GDB_SIZEOF_REG)
+#define DBG_MAX_REG_NUM 36
+#define NUMREGBYTES (DBG_MAX_REG_NUM * GDB_SIZEOF_REG)
 #define CACHE_FLUSH_IS_SAFE     1
 #define BUFMAX                  2048
+static_assert(BUFMAX > NUMREGBYTES,
+	      "As per KGDB documentation, BUFMAX must be larger than NUMREGBYTES");
 #ifdef CONFIG_RISCV_ISA_C
 #define BREAK_INSTR_SIZE	2
 #else
@@ -97,6 +101,7 @@ extern unsigned long kgdb_compiled_break;
 #define DBG_REG_STATUS_OFF 33
 #define DBG_REG_BADADDR_OFF 34
 #define DBG_REG_CAUSE_OFF 35
+/* NOTE: increase DBG_MAX_REG_NUM if you add more values here. */
 
 extern const char riscv_gdb_stub_feature[64];
 

arch/riscv/kernel/cpu-hotplug.c

@@ -54,6 +54,7 @@ void arch_cpuhp_cleanup_dead_cpu(unsigned int cpu)
 
 	pr_notice("CPU%u: off\n", cpu);
 
+	clear_tasks_mm_cpumask(cpu);
 	/* Verify from the firmware if the cpu is really stopped*/
 	if (cpu_ops->cpu_is_stopped)
 		ret = cpu_ops->cpu_is_stopped(cpu);

arch/riscv/kernel/entry.S

@@ -455,7 +455,7 @@ SYM_DATA_START_LOCAL(excp_vect_table)
 	RISCV_PTR do_trap_ecall_s
 	RISCV_PTR do_trap_unknown
 	RISCV_PTR do_trap_ecall_m
-	/* instruciton page fault */
+	/* instruction page fault */
 	ALT_PAGE_FAULT(RISCV_PTR do_page_fault)
 	RISCV_PTR do_page_fault   /* load page fault */
 	RISCV_PTR do_trap_unknown

arch/riscv/kernel/probes/kprobes.c

@@ -49,10 +49,15 @@ static void __kprobes arch_simulate_insn(struct kprobe *p, struct pt_regs *regs)
 	post_kprobe_handler(p, kcb, regs);
 }
 
-static bool __kprobes arch_check_kprobe(struct kprobe *p)
+static bool __kprobes arch_check_kprobe(unsigned long addr)
 {
-	unsigned long tmp  = (unsigned long)p->addr - p->offset;
-	unsigned long addr = (unsigned long)p->addr;
+	unsigned long tmp, offset;
+
+	/* start iterating at the closest preceding symbol */
+	if (!kallsyms_lookup_size_offset(addr, NULL, &offset))
+		return false;
+
+	tmp = addr - offset;
 
 	while (tmp <= addr) {
 		if (tmp == addr)
@@ -71,7 +76,7 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
 	if ((unsigned long)insn & 0x1)
 		return -EILSEQ;
 
-	if (!arch_check_kprobe(p))
+	if (!arch_check_kprobe((unsigned long)p->addr))
 		return -EILSEQ;
 
 	/* copy instruction */

arch/riscv/kernel/setup.c

@@ -331,11 +331,14 @@ void __init setup_arch(char **cmdline_p)
 	/* Parse the ACPI tables for possible boot-time configuration */
 	acpi_boot_table_init();
 
+	if (acpi_disabled) {
 #if IS_ENABLED(CONFIG_BUILTIN_DTB)
-	unflatten_and_copy_device_tree();
+		unflatten_and_copy_device_tree();
 #else
-	unflatten_device_tree();
+		unflatten_device_tree();
 #endif
+	}
+
 	misc_mem_init();
 
 	init_resources();

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

@@ -11,14 +11,14 @@
 #define KPROBE_TEST_MAGIC_LOWER    0x0000babe
 #define KPROBE_TEST_MAGIC_UPPER    0xcafe0000
 
-#ifndef __ASSEMBLY__
+#ifndef __ASSEMBLER__
 
 /* array of addresses to install kprobes */
 extern void *test_kprobes_addresses[];
 
 /* array of functions that return KPROBE_TEST_MAGIC */
 extern long (*test_kprobes_functions[])(void);
 
-#endif /* __ASSEMBLY__ */
+#endif /* __ASSEMBLER__ */
 
 #endif /* TEST_KPROBES_H */