| Message ID | 20240117130933.57514-2-ajones@ventanamicro.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 0de65288d75ff96c30e216557d979fb9342c4323 |
| Headers | show |
| Series | RISC-V: selftests: cbo: Ensure asm operands match constraints | expand |
Hello: This patch was applied to riscv/linux.git (fixes) by Palmer Dabbelt <palmer@rivosinc.com>: On Wed, 17 Jan 2024 14:09:34 +0100 you wrote: > The 'i' constraint expects a constant operand, which fn and its > constant derivative MK_CBO(fn) are, but passing fn through a function > as a parameter and using a local variable for MK_CBO(fn) allow the > compiler to lose sight of that when no optimization is done. Use > a macro instead of a function and skip the local variable to ensure > the compiler uses constants, matching the asm constraints. > > [...] Here is the summary with links: - RISC-V: selftests: cbo: Ensure asm operands match constraints https://git.kernel.org/riscv/c/0de65288d75f You are awesome, thank you!
diff --git a/tools/testing/selftests/riscv/hwprobe/cbo.c b/tools/testing/selftests/riscv/hwprobe/cbo.c index c6a83ab11e22..c537d52fafc5 100644 --- a/tools/testing/selftests/riscv/hwprobe/cbo.c +++ b/tools/testing/selftests/riscv/hwprobe/cbo.c @@ -36,16 +36,14 @@ static void sigill_handler(int sig, siginfo_t *info, void *context) regs[0] += 4; } -static void cbo_insn(char *base, int fn) -{ - uint32_t insn = MK_CBO(fn); - - asm volatile( - "mv a0, %0\n" - "li a1, %1\n" - ".4byte %2\n" - : : "r" (base), "i" (fn), "i" (insn) : "a0", "a1", "memory"); -} +#define cbo_insn(base, fn) \ +({ \ + asm volatile( \ + "mv a0, %0\n" \ + "li a1, %1\n" \ + ".4byte %2\n" \ + : : "r" (base), "i" (fn), "i" (MK_CBO(fn)) : "a0", "a1", "memory"); \ +}) static void cbo_inval(char *base) { cbo_insn(base, 0); } static void cbo_clean(char *base) { cbo_insn(base, 1); }
The 'i' constraint expects a constant operand, which fn and its constant derivative MK_CBO(fn) are, but passing fn through a function as a parameter and using a local variable for MK_CBO(fn) allow the compiler to lose sight of that when no optimization is done. Use a macro instead of a function and skip the local variable to ensure the compiler uses constants, matching the asm constraints. Reported-by: Yunhui Cui <cuiyunhui@bytedance.com> Closes: https://lore.kernel.org/all/20240117082514.42967-1-cuiyunhui@bytedance.com Fixes: a29e2a48afe3 ("RISC-V: selftests: Add CBO tests") Signed-off-by: Andrew Jones <ajones@ventanamicro.com> --- tools/testing/selftests/riscv/hwprobe/cbo.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-)