| Message ID | 20180119194648.25501-1-ard.biesheuvel@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | target/arm: Fix 32-bit address truncation | expand |
On 19 January 2018 at 19:46, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote: > Commit ("3b39d734141a target/arm: Handle page table walk load failures > correctly") modified both versions of the page table walking code (i.e., > arm_ldl_ptw and arm_ldq_ptw) to record the result of the translation in > a temporary 'data' variable so that it can be inspected before being > returned. However, arm_ldq_ptw() returns an uint64_t, and using a > temporary uint32_t variable truncates the upper bits, corrupting the > result. This causes problems when using more than 4 GB of memory in > a TCG guest. So use a uint64_t instead. > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Oops. As you probably guessed, I wrote the 32-bit load function first and then failed to update it correctly when writing the 64-bit version... Applied to target-arm.next, thanks. -- PMM
diff --git a/target/arm/helper.c b/target/arm/helper.c index 67059033019c..a41b6c3a1b82 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -8368,7 +8368,7 @@ static uint64_t arm_ldq_ptw(CPUState *cs, hwaddr addr, bool is_secure, MemTxAttrs attrs = {}; MemTxResult result = MEMTX_OK; AddressSpace *as; - uint32_t data; + uint64_t data; attrs.secure = is_secure; as = arm_addressspace(cs, attrs);
Commit ("3b39d734141a target/arm: Handle page table walk load failures correctly") modified both versions of the page table walking code (i.e., arm_ldl_ptw and arm_ldq_ptw) to record the result of the translation in a temporary 'data' variable so that it can be inspected before being returned. However, arm_ldq_ptw() returns an uint64_t, and using a temporary uint32_t variable truncates the upper bits, corrupting the result. This causes problems when using more than 4 GB of memory in a TCG guest. So use a uint64_t instead. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- target/arm/helper.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)