From 812258ff4166bcd41c7d44707e0591f9ae32ac8c Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Mon, 8 Sep 2025 14:12:35 +0100 Subject: [PATCH 1/8] rust: cfi: only 64-bit arm and x86 support CFI_CLANG The kernel uses the standard rustc targets for non-x86 targets, and out of those only 64-bit arm's target has kcfi support enabled. For x86, the custom 64-bit target enables kcfi. The HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC config option that allows CFI_CLANG to be used in combination with RUST does not check whether the rustc target supports kcfi. This breaks the build on riscv (and presumably 32-bit arm) when CFI_CLANG and RUST are enabled at the same time. Ordinarily, a rustc-option check would be used to detect target support but unfortunately rustc-option filters out the target for reasons given in commit 46e24a545cdb4 ("rust: kasan/kbuild: fix missing flags on first build"). As a result, if the host supports kcfi but the target does not, e.g. when building for riscv on x86_64, the build would remain broken. Instead, make HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC depend on the only two architectures where the target used supports it to fix the build. CC: stable@vger.kernel.org Fixes: ca627e636551e ("rust: cfi: add support for CFI_CLANG with Rust") Signed-off-by: Conor Dooley Acked-by: Miguel Ojeda Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20250908-distill-lint-1ae78bcf777c@spud Signed-off-by: Paul Walmsley --- arch/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/Kconfig b/arch/Kconfig index ebe08b9186ad..74ff01133532 100644 --- a/arch/Kconfig +++ b/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) From 781380d2cdef34559a0125ca6464b90bfc01594f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Miquel=20Sabat=C3=A9=20Sol=C3=A0?= Date: Mon, 15 Sep 2025 16:32:52 +0200 Subject: [PATCH 2/8] riscv: kgdb: Ensure that BUFMAX > NUMREGBYTES MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The current value of BUFMAX is similar as in other architectures, but as per documentation on KGDB (see 'Documentation/process/debugging/kgdb.rst'), BUFMAX has to be larger than NUMREGBYTES. Some NUMREGBYTES architectures (e.g. powerpc or hexagon) actually define BUFMAX in relation to NUMREGBYTES, and thus this condition is always guaranteed. Since 2048 is a value that is generally accepted on all architectures, and that is larger than the current value of NUMREGBYTES, we can keep this value in arch/riscv, but we can at least add an 'static_assert' as an extra measure just in case NUMREGBYTES changes in the future for some unforseen reason. Signed-off-by: Miquel Sabaté Solà Link: https://lore.kernel.org/r/20250915143252.154955-1-mikisabate@gmail.com Signed-off-by: Paul Walmsley --- arch/riscv/include/asm/kgdb.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/riscv/include/asm/kgdb.h b/arch/riscv/include/asm/kgdb.h index 7559d728c5ff..78b18e2fd771 100644 --- a/arch/riscv/include/asm/kgdb.h +++ b/arch/riscv/include/asm/kgdb.h @@ -3,14 +3,18 @@ #ifndef __ASM_KGDB_H_ #define __ASM_KGDB_H_ +#include + #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]; From ae9e9f3d67dcef7582a4524047b01e33c5185ddb Mon Sep 17 00:00:00 2001 From: Danil Skrebenkov Date: Fri, 19 Sep 2025 16:28:46 +0300 Subject: [PATCH 3/8] RISC-V: clear hot-unplugged cores from all task mm_cpumasks to avoid rfence errors openSBI v1.7 adds harts checks for ipi operations. Especially it adds comparison between hmask passed as an argument from linux and mask of online harts (from openSBI side). If they don't fit each other the error occurs. When cpu is offline, cpu_online_mask is explicitly cleared in __cpu_disable. However, there is no explicit clearing of mm_cpumask. mm_cpumask is used for rfence operations that call openSBI RFENCE extension which uses ipi to remote harts. If hart is offline there may be error if mask of linux is not as mask of online harts in openSBI. this patch adds explicit clearing of mm_cpumask for offline hart. Signed-off-by: Danil Skrebenkov Reviewed-by: Andrew Jones Link: https://lore.kernel.org/r/20250919132849.31676-1-danil.skrebenkov@cloudbear.ru [pjw@kernel.org: rewrote subject line for clarity] Signed-off-by: Paul Walmsley --- arch/riscv/kernel/cpu-hotplug.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/riscv/kernel/cpu-hotplug.c b/arch/riscv/kernel/cpu-hotplug.c index a1e38ecfc8be..3f50d3dd76c6 100644 --- a/arch/riscv/kernel/cpu-hotplug.c +++ b/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); From c199745d3ac3f836515a5734a6ca5c6f55a8809b Mon Sep 17 00:00:00 2001 From: Florian Schmaus Date: Mon, 6 Oct 2025 11:37:42 +0200 Subject: [PATCH 4/8] riscv: entry: fix typo in comment 'instruciton' -> 'instruction' Fix a typo in a comment in the RISC-V entry.S. Signed-off-by: Florian Schmaus Link: https://lore.kernel.org/r/20251006093742.53925-1-flo@geekplace.eu [pjw@kernel.org: wrote a basic patch description] Signed-off-by: Paul Walmsley --- arch/riscv/kernel/entry.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index d3d92a4becc7..9b9dec6893b8 100644 --- a/arch/riscv/kernel/entry.S +++ b/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 From 9e68bd803fac49274fde914466fd3b07c4d602c8 Mon Sep 17 00:00:00 2001 From: Fabian Vogt Date: Wed, 10 Sep 2025 17:25:13 +0200 Subject: [PATCH 5/8] riscv: kprobes: Fix probe address validation When adding a kprobe such as "p:probe/tcp_sendmsg _text+15392192", arch_check_kprobe would start iterating all instructions starting from _text until the probed address. Not only is this very inefficient, but literal values in there (e.g. left by function patching) are misinterpreted in a way that causes a desync. Fix this by doing it like x86: start the iteration at the closest preceding symbol instead of the given starting point. Fixes: 87f48c7ccc73 ("riscv: kprobe: Fixup kernel panic when probing an illegal position") Signed-off-by: Fabian Vogt Signed-off-by: Marvin Friedrich Acked-by: Guo Ren Link: https://lore.kernel.org/r/6191817.lOV4Wx5bFT@fvogt-thinkpad Signed-off-by: Paul Walmsley --- arch/riscv/kernel/probes/kprobes.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/kprobes.c index c0738d6c6498..8723390c7cad 100644 --- a/arch/riscv/kernel/probes/kprobes.c +++ b/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 */ From 69a8b62a7aa1e54ff7623064f6507fa29c1d0d4e Mon Sep 17 00:00:00 2001 From: Han Gao Date: Wed, 10 Sep 2025 19:24:01 +0800 Subject: [PATCH 6/8] riscv: acpi: avoid errors caused by probing DT devices when ACPI is used Similar to the ARM64 commit 3505f30fb6a9s ("ARM64 / ACPI: If we chose to boot from acpi then disable FDT"), let's not do DT hardware probing if ACPI is enabled in early boot. This avoids errors caused by repeated driver probing. Signed-off-by: Han Gao Link: https://lore.kernel.org/r/20250910112401.552987-1-rabenda.cn@gmail.com [pjw@kernel.org: cleaned up patch description and subject] Signed-off-by: Paul Walmsley --- arch/riscv/kernel/setup.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index 14235e58c539..b5bc5fc65cea 100644 --- a/arch/riscv/kernel/setup.c +++ b/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(); From 7882d2c45ccba538cddb0615a893a008dd2efcde Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= Date: Thu, 9 Oct 2025 11:18:48 +0200 Subject: [PATCH 7/8] riscv: Respect dependencies of ARCH_HAS_ELF_CORE_EFLAGS MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This kconfig symbol has dependencies and is only selectable if those dependencies are also enabled. Respect the dependencies. Fixes the following warning when configuring an 'allnoconfig': WARNING: unmet direct dependencies detected for ARCH_HAS_ELF_CORE_EFLAGS Depends on [n]: BINFMT_ELF [=n] && ELF_CORE [=y] Selected by [y]: - RISCV [=y] Fixes: 8c94db0ae97c ("binfmt_elf: preserve original ELF e_flags for core dumps") Signed-off-by: Thomas Weißschuh Link: https://lore.kernel.org/r/20251009-riscv-elf-core-eflags-v1-1-e9b45ab6b36d@linutronix.de Signed-off-by: Paul Walmsley --- arch/riscv/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 0c6038dc5dfd..22cda9c452d2 100644 --- a/arch/riscv/Kconfig +++ b/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 From 852947be66b826c3d0ba328e19a3559fdf7ac726 Mon Sep 17 00:00:00 2001 From: Paul Walmsley Date: Fri, 10 Oct 2025 15:50:24 -0600 Subject: [PATCH 8/8] riscv: kprobes: convert one final __ASSEMBLY__ to __ASSEMBLER__ Per the reasoning in commit f811f58597ac ("riscv: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-uapi headers"), convert one last remaining instance of __ASSEMBLY__ in the arch/riscv kprobes code. This entered the tree from patches that were sent before Thomas' changes; and when I reviewed the kprobes patches before queuing them, I missed this instance. Cc: Nam Cao Cc: Thomas Huth Link: https://lore.kernel.org/linux-riscv/16b74b63-f223-4f0b-b6e5-31cea5e620b4@redhat.com/ Link: https://lore.kernel.org/linux-riscv/20250606070952.498274-1-thuth@redhat.com/ Signed-off-by: Paul Walmsley --- arch/riscv/kernel/tests/kprobes/test-kprobes.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/riscv/kernel/tests/kprobes/test-kprobes.h b/arch/riscv/kernel/tests/kprobes/test-kprobes.h index 3886ab491ecb..537f44aa9d3f 100644 --- a/arch/riscv/kernel/tests/kprobes/test-kprobes.h +++ b/arch/riscv/kernel/tests/kprobes/test-kprobes.h @@ -11,7 +11,7 @@ #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[]; @@ -19,6 +19,6 @@ 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 */