[PATCH fixes v2 1/2] riscv: Replace function-like macro by static inline function

[PATCH fixes v2 1/2] riscv: Replace function-like macro by static inline function

[Björn Töpel]

From: Björn Töpel <bjorn@rivosinc.com>

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 <bjorn@rivosinc.com>
---
 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);

base-commit: 8560697b23dc2f405cb463af2b17256a9888129d
-- 
2.45.2

[PATCH fixes v2 2/2] riscv: uprobes: Add missing fence.i after building the XOL buffer

[Björn Töpel]

From: Björn Töpel <bjorn@rivosinc.com>

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 <guoren@kernel.org>
Fixes: 74784081aac8 ("riscv: Add uprobes supported")
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
---
v2: Correct flush range (Samuel)
---
 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);
 }
-- 
2.45.2

Re: [PATCH fixes v2 1/2] riscv: Replace function-like macro by static inline function

[patchwork-bot+linux-riscv]

Hello:

This series was applied to riscv/linux.git (fixes)
by Palmer Dabbelt <palmer@rivosinc.com>:

On Sat, 19 Apr 2025 13:13:59 +0200 you wrote:
> From: Björn Töpel <bjorn@rivosinc.com>
> 
> 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.
> 
> [...]

Here is the summary with links:
  - [fixes,v2,1/2] riscv: Replace function-like macro by static inline function
    https://git.kernel.org/riscv/c/121f34341d39
  - [fixes,v2,2/2] riscv: uprobes: Add missing fence.i after building the XOL buffer
    https://git.kernel.org/riscv/c/7d1d19a11cfb

You are awesome, thank you!
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