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Diffstat (limited to 'classification/test_mails/mail_semantic_1')
| -rw-r--r-- | classification/test_mails/mail_semantic_1 | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/classification/test_mails/mail_semantic_1 b/classification/test_mails/mail_semantic_1 new file mode 100644 index 000000000..af6a2480d --- /dev/null +++ b/classification/test_mails/mail_semantic_1 @@ -0,0 +1,21 @@ +AArch64: ISV is set to 1 in ESR_EL2 when taking a data abort with post-indexed instructions + +I think that I have a Qemu bug in my hands, but, I could still be missing something. Consider the following instruction: +0x0000000000000000: C3 44 00 B8 str w3, [x6], #4 + +notice the last #4, I think this is what we would call a post-indexed instruction (falls into the category of instructions with writeback). As I understand it, those instructions should not have ISV=1 in ESR_EL2 when faulting. + +Here is the relevant part of the manual: + +For other faults reported in ESR_EL2, ISV is 0 except for the following stage 2 aborts: +• AArch64 loads and stores of a single general-purpose register (including the register specified with 0b11111, including those with Acquire/Release semantics, but excluding Load Exclusive or Store Exclusive and excluding those with writeback). + + +However, I can see that Qemu sets ISV to 1 here. The ARM hardware that I tested gave me a value of ISV=0 for similar instructions. + +Another example of instruction: 0x00000000000002f8: 01 1C 40 38 ldrb w1, [x0, #1]!""" +reproduce = """1. Run some hypervisor in EL2 +2. Create a guest running at EL1 that executes one of the mentioned instructions (and make the instruction fault by writing to some unmapped page in SLP) +3. Observe the value of ESR_EL2 on data abort + +Unfortunately, I cannot provide an image to reproduce this (the software is not open-source). But, I would be happy to help test a patch. |