Support for new CHERI128 trace format from hardware. #3
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streamtrace.cc
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| uint64_t edgbits = (botbits-0x100ULL)&0xFFFFFULL; | ||
| uint64_t ptrbits = (ptr>>exp)&0xFFFFFULL; | ||
| uint8_t ptrHi = (ptrbits < edgbits); |
streamtrace.cc
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| uint8_t botHi = (botbits < edgbits); | ||
| uint8_t topHi = (topbits < edgbits); | ||
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| uint64_t bigOne = 1ULL<<(exp+20ULL); |
| * on the trace format. val1/pc is the 1st half of the capability containing the | ||
| * pointer and val2 is the 2nd half of the compressed capability containing the | ||
| * bounds and permissions. | ||
| */ |
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The first half of this comment is confusing, as it's talking about where these values come from long before they get to this function.
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Yes. This is brought forward from the older variations of this function. If we want to change the comment, we should change it everywhere.
streamtrace.cc
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| cap->type = 0; // TODO extract type from typed capabilities | ||
| cap->permissions = extract_bits<63,49>(val2); | ||
| uint64_t exp = extract_bits<46,41>(val2); | ||
| uint64_t mask = ((uint64_t) ~0)<<20ULL; |
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I think I can figure out what this is doing, but please add a comment explaining it.
streamtrace.cc
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| uint64_t botbits = extract_bits<39,20>(val2);//(half2>>20) & 0xFFFFFULL; | ||
| uint64_t bot = (ptr&mask)|(botbits<<exp); | ||
| uint64_t topbits = (half2) & 0xFFFFFULL; | ||
| uint64_t top = (ptr&mask)|(topbits<<exp); |
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There's some quite random spacing here...
…future cheritrace with compressed capability support.
…d specific cutting point in the loop will be different.
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This has not been compiled yet! It should have the main components and details ported from berictl, but I don't yet have a setup to be able to compile.
Main missing feature is extracting the type for sealed capabilities and accounting for the type information in the lower parts of the top and bottom fields when the capability is sealed.