Newer gcc compiler (version 16.0.0 20260103 (Red Hat 16.0.0-0) (GCC))
detects a truncation error:
../target/riscv/cpu.c: In function ‘riscv_isa_write_fdt’:
../target/riscv/cpu.c:2916:35: error: ‘%d’ directive output may be truncated writing between 1 and 11 bytes into a region of size 5 [-Werror=format-truncation=]
2916 | snprintf(isa_base, maxlen, "rv%di", xlen);
| ^~
../target/riscv/cpu.c:2916:32: note: directive argument in the range [-2147483648, 2147483632]
2916 | snprintf(isa_base, maxlen, "rv%di", xlen);
| ^~~~~~~
Since the xlen variable represents the register width (32, 64, 128) in
the RISC-V base ISA name, mask its value with a 8-bit bitmask to
satisfy the size constraints on the snprintf output.
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Alistair Francis <alistair.francis@wdc.com>
Cc: Weiwei Li <liwei1518@gmail.com>
Cc: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Cc: Liu Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Daniel Henrique Barboza <daniel.barboza@oss.qualcomm.com>
Link: https://lore.kernel.org/qemu-devel/20260112161626.1232639-1-clg@redhat.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
target/riscv/cpu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
index ffd98e8eed468645b8ceb8a7adb45718bdc4444d..e95eea024939d2cbb5747781c291fed0e1b07bb9 100644
--- a/target/riscv/cpu.c
+++ b/target/riscv/cpu.c
@@ -2913,7 +2913,7 @@ void riscv_isa_write_fdt(RISCVCPU *cpu, void *fdt, char *nodename)
riscv_isa = riscv_isa_string(cpu);
qemu_fdt_setprop_string(fdt, nodename, "riscv,isa", riscv_isa);
- snprintf(isa_base, maxlen, "rv%di", xlen);
+ snprintf(isa_base, maxlen, "rv%di", xlen & 0xFF);
qemu_fdt_setprop_string(fdt, nodename, "riscv,isa-base", isa_base);
isa_extensions = riscv_isa_extensions_list(cpu, &count);
--
2.52.0