More fixes for parallel parsing, spring boards, and ARM #592
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…this jump is the only incoming edge of the targXXX function, we should not treat this jump as a tail call. In theory, it is reasonable either way. However, treating such jump as a tail call can cause troubles for function entry instrumentation. If the targXXX function may jump back to the original function, and thus reach the tail jump. This becomes a recursive tail call. However, Dyninst relocation seems to have problem adjusting the tail jump to include entry instrumentation. 2. If the determination of a tail call is changed, we should re-compute function boundaries, including ret blocks, exit blocks, call edges
DT_DYNINST entry of the .dynamic section points the memory offset of the trap mapping header. Should use this information to locate trap mapping table when adjusting trap mapping entries for PIC code
This patch deals with issues where incorrect springboards could be generated. Specifically addresses three issues: 1. Springboards trampling function data (addresses github issue #551) 2. Required springboards being spilling over block bounds onto other required springboards. Prior a if two required springboards were located near each other, there was a chance that one of the springboards could be partially overwritten resulting in broken behavior. 3. Unsafe reusage of a codegen object where if a trap was needed, both a branch and a trap would be written causing bad behavior.
…ic<int>, rather than just int. A block can be shared by multiple functions. So, when multiple functions add/remove blocks at the same time, there will be race conditions.
users insert a snippet. The user can continue to insert more snippets to the same function, which will trigger Dyninst to perform the additional relocation. So, we need to overwrite existing springboard for newly added instrumentations. In other words, we need to overwrite existing springboards if the existing ones were installed in previous relocations.
…Entry" and "IndirBlockEntry". Only "FuncEntry" springboards are required because control flow enter instrumentation through function calls (we relocate the whole function even if only a part of the function is instrumented). "IndirBlockEntry" springboards are important for re-directing control flow from jump tables back to instrumentation. But, it is not as important as "FuncEntry". 2. Jumps to code in another secion should be treated as tail calls.
…nt orders, which lead to non-deterministic slicing and non-determinisitc jump table analysis. Therefore, we need to sort source edges in slicing based on the edge's source block address and edge type to ensure deterministic slicing.
…itecture specific source files.
…cfs. We fall back to use ptrace if procfs read & write fail. This change is for fixing icache coherence issue for ARM dynamic instrumentaiton. ARM architecture does not guarantee icache-dcache coherence. And writes through ptrace does not seem to invalidate icache contents and caused SIGILLs
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Fixes #577 |
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Fixes #551 |
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Regressions on x86 for test5 series with static linking in rewriter mode (PIC and nonPIC). |
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Re-test the PR with the latest master on all three platforms and no regressions. |
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