| Message ID | 20221122155515.2426188-1-ardb@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] target/arm: Use signed quantity to represent VMSAv8-64 translation level | expand |
On Tue, 22 Nov 2022 at 15:55, Ard Biesheuvel <ardb@kernel.org> wrote: > > The LPA2 extension implements 52-bit virtual addressing for 4k and 16k > translation granules, and for the former, this means an additional level > of translation is needed. This means we start counting at -1 instead of > 0 when doing a walk, and so 'level' is now a signed quantity, and should > be typed as such. So turn it from uint32_t into int32_t. > > This avoids a level of -1 getting misinterpreted as being >= 3, and > terminating a page table walk prematurely with a bogus output address. > > Cc: Peter Maydell <peter.maydell@linaro.org> > Cc: Philippe Mathieu-Daudé <f4bug@amsat.org> > Cc: Richard Henderson <richard.henderson@linaro.org> > Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Applied to target-arm.next for 7.2, thanks. -- PMM
diff --git a/target/arm/ptw.c b/target/arm/ptw.c index 9a6277d862fac229..1d9bb4448761ddf4 100644 --- a/target/arm/ptw.c +++ b/target/arm/ptw.c @@ -1172,7 +1172,7 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw, ARMCPU *cpu = env_archcpu(env); ARMMMUIdx mmu_idx = ptw->in_mmu_idx; bool is_secure = ptw->in_secure; - uint32_t level; + int32_t level; ARMVAParameters param; uint64_t ttbr; hwaddr descaddr, indexmask, indexmask_grainsize; @@ -1302,7 +1302,7 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw, */ uint32_t sl0 = extract32(tcr, 6, 2); uint32_t sl2 = extract64(tcr, 33, 1); - uint32_t startlevel; + int32_t startlevel; bool ok; /* SL2 is RES0 unless DS=1 & 4kb granule. */
The LPA2 extension implements 52-bit virtual addressing for 4k and 16k translation granules, and for the former, this means an additional level of translation is needed. This means we start counting at -1 instead of 0 when doing a walk, and so 'level' is now a signed quantity, and should be typed as such. So turn it from uint32_t into int32_t. This avoids a level of -1 getting misinterpreted as being >= 3, and terminating a page table walk prematurely with a bogus output address. Cc: Peter Maydell <peter.maydell@linaro.org> Cc: Philippe Mathieu-Daudé <f4bug@amsat.org> Cc: Richard Henderson <richard.henderson@linaro.org> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- target/arm/ptw.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)