From 121f34341d396b666d8a90b24768b40e08ca0d61 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Sat, 19 Apr 2025 13:13:59 +0200 Subject: [PATCH 1/2] riscv: Replace function-like macro by static inline function MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The flush_icache_range() function is implemented as a "function-like macro with unused parameters", which can result in "unused variables" warnings. Replace the macro with a static inline function, as advised by Documentation/process/coding-style.rst. Fixes: 08f051eda33b ("RISC-V: Flush I$ when making a dirty page executable") Signed-off-by: Björn Töpel Link: https://lore.kernel.org/r/20250419111402.1660267-1-bjorn@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/cacheflush.h | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/arch/riscv/include/asm/cacheflush.h b/arch/riscv/include/asm/cacheflush.h index 8de73f91bfa3..b59ffeb668d6 100644 --- a/arch/riscv/include/asm/cacheflush.h +++ b/arch/riscv/include/asm/cacheflush.h @@ -34,11 +34,6 @@ static inline void flush_dcache_page(struct page *page) flush_dcache_folio(page_folio(page)); } -/* - * RISC-V doesn't have an instruction to flush parts of the instruction cache, - * so instead we just flush the whole thing. - */ -#define flush_icache_range(start, end) flush_icache_all() #define flush_icache_user_page(vma, pg, addr, len) \ do { \ if (vma->vm_flags & VM_EXEC) \ @@ -78,6 +73,16 @@ void flush_icache_mm(struct mm_struct *mm, bool local); #endif /* CONFIG_SMP */ +/* + * RISC-V doesn't have an instruction to flush parts of the instruction cache, + * so instead we just flush the whole thing. + */ +#define flush_icache_range flush_icache_range +static inline void flush_icache_range(unsigned long start, unsigned long end) +{ + flush_icache_all(); +} + extern unsigned int riscv_cbom_block_size; extern unsigned int riscv_cboz_block_size; void riscv_init_cbo_blocksizes(void); From 7d1d19a11cfbfd8bae1d89cc010b2cc397cd0c48 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= Date: Sat, 19 Apr 2025 13:14:00 +0200 Subject: [PATCH 2/2] riscv: uprobes: Add missing fence.i after building the XOL buffer MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The XOL (execute out-of-line) buffer is used to single-step the replaced instruction(s) for uprobes. The RISC-V port was missing a proper fence.i (i$ flushing) after constructing the XOL buffer, which can result in incorrect execution of stale/broken instructions. This was found running the BPF selftests "test_progs: uprobe_autoattach, attach_probe" on the Spacemit K1/X60, where the uprobes tests randomly blew up. Reviewed-by: Guo Ren Fixes: 74784081aac8 ("riscv: Add uprobes supported") Signed-off-by: Björn Töpel Link: https://lore.kernel.org/r/20250419111402.1660267-2-bjorn@kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/probes/uprobes.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) diff --git a/arch/riscv/kernel/probes/uprobes.c b/arch/riscv/kernel/probes/uprobes.c index 4b3dc8beaf77..cc15f7ca6cc1 100644 --- a/arch/riscv/kernel/probes/uprobes.c +++ b/arch/riscv/kernel/probes/uprobes.c @@ -167,6 +167,7 @@ void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr, /* Initialize the slot */ void *kaddr = kmap_atomic(page); void *dst = kaddr + (vaddr & ~PAGE_MASK); + unsigned long start = (unsigned long)dst; memcpy(dst, src, len); @@ -176,13 +177,6 @@ void arch_uprobe_copy_ixol(struct page *page, unsigned long vaddr, *(uprobe_opcode_t *)dst = __BUG_INSN_32; } + flush_icache_range(start, start + len); kunmap_atomic(kaddr); - - /* - * We probably need flush_icache_user_page() but it needs vma. - * This should work on most of architectures by default. If - * architecture needs to do something different it can define - * its own version of the function. - */ - flush_dcache_page(page); }