On Tue, Dec 3, 2024 at 8:34 PM Philippe Mathieu-Daudé <[email protected]> wrote: > > From: Peter Maydell <[email protected]> > > In riscv_cpu_do_interrupt() we use the 'cause' value we got out of > cs->exception as a shift value. However this value can be larger > than 31, which means that "1 << cause" is undefined behaviour, > because we do the shift on an 'int' type. > > This causes the undefined behaviour sanitizer to complain > on one of the check-tcg tests: > > $ UBSAN_OPTIONS=print_stacktrace=1:abort_on_error=1:halt_on_error=1 > ./build/clang/qemu-system-riscv64 -M virt -semihosting -display none -device > loader,file=build/clang/tests/tcg/riscv64-softmmu/issue1060 > ../../target/riscv/cpu_helper.c:1805:38: runtime error: shift exponent 63 is > too large for 32-bit type 'int' > #0 0x55f2dc026703 in riscv_cpu_do_interrupt > /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/clang/../../target/riscv/cpu_helper.c:1805:38 > #1 0x55f2dc3d170e in cpu_handle_exception > /mnt/nvmedisk/linaro/qemu-from-laptop/qemu/build/clang/../../accel/tcg/cpu-exec.c:752:9 > > In this case cause is RISCV_EXCP_SEMIHOST, which is 0x3f. > > Use 1ULL instead to ensure that the shift is in range. > > Signed-off-by: Peter Maydell <[email protected]> > Fixes: 1697837ed9 ("target/riscv: Add M-mode virtual interrupt and IRQ > filtering support.") > Fixes: 40336d5b1d ("target/riscv: Add HS-mode virtual interrupt and IRQ > filtering support.") > Reviewed-by: Daniel Henrique Barboza <[email protected]> > Reviewed-by: Richard Henderson <[email protected]> > Reviewed-by: Alistair Francis <[email protected]> > Message-ID: <[email protected]> > Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Thanks! I was just about to prep this, thanks for beating me to it :) [email protected] this should be backported where it applies Alistair > --- > target/riscv/cpu_helper.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c > index 0a3ead69eab..45806f5ab0f 100644 > --- a/target/riscv/cpu_helper.c > +++ b/target/riscv/cpu_helper.c > @@ -1802,10 +1802,10 @@ void riscv_cpu_do_interrupt(CPUState *cs) > bool async = !!(cs->exception_index & RISCV_EXCP_INT_FLAG); > target_ulong cause = cs->exception_index & RISCV_EXCP_INT_MASK; > uint64_t deleg = async ? env->mideleg : env->medeleg; > - bool s_injected = env->mvip & (1 << cause) & env->mvien && > - !(env->mip & (1 << cause)); > - bool vs_injected = env->hvip & (1 << cause) & env->hvien && > - !(env->mip & (1 << cause)); > + bool s_injected = env->mvip & (1ULL << cause) & env->mvien && > + !(env->mip & (1ULL << cause)); > + bool vs_injected = env->hvip & (1ULL << cause) & env->hvien && > + !(env->mip & (1ULL << cause)); > target_ulong tval = 0; > target_ulong tinst = 0; > target_ulong htval = 0; > -- > 2.45.2 > >
