[PATCH 3/4] riscv: ptdump: use seq_puts() in pt_dump_seq_puts() macro

Josephine Pfeiffer hi at josie.lol
Sat Oct 18 10:04:51 PDT 2025


The pt_dump_seq_puts() macro incorrectly uses seq_printf() instead of
seq_puts(). This is both a performance issue and conceptually wrong,
as the macro name suggests plain string output (puts) but the
implementation uses formatted output (printf).

The macro is used in ptdump.c:301 to output a newline character. Using
seq_printf() adds unnecessary overhead for format string parsing when
outputting this constant string.

This bug was introduced in commit 59c4da8640cc ("riscv: Add support to
dump the kernel page tables") in 2020, which copied the implementation
pattern from other architectures that had the same bug.

Fixes: 59c4da8640cc ("riscv: Add support to dump the kernel page tables")
Signed-off-by: Josephine Pfeiffer <hi at josie.lol>
---
 arch/riscv/mm/ptdump.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/mm/ptdump.c b/arch/riscv/mm/ptdump.c
index 3b51690cc876..34299c2b231f 100644
--- a/arch/riscv/mm/ptdump.c
+++ b/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);	\
 })
 
 /*
-- 
2.51.1.dirty




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