i#5505 kernel tracing: Add syscall instr encodings #6479
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Adds encodings for kernel system call instructions to the trace in raw2trace. Kernel system call traces are decoded using libipt which also provides the instruction encodings. We write these encodings to a new buffer which is re-used for all dynamic instances of that instr. Adds a new drcachesim option to ignore failures in decoding instructions. This is currently required because the kernel traces have opcodes that are not yet recognized. Such decode failures are not critical because their impact is limited (not counting unsupported instrs in the opcode_mix tool, or not showing unsupported instrs in the view tool) unlike user-space instrs where missing decoder support may lead to drreg issues etc. Uses the new option in opcode_mix and the view tool. Adds support in the syscall_mix tool to report the counts of each system call's trace also. Issue: #5505
abhinav92003
commented
Nov 28, 2023
abhinav92003
commented
Nov 30, 2023
derekbruening
approved these changes
Nov 30, 2023
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x86-32 failures are #6417. |
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Adds encodings for kernel system call instructions to the trace in raw2trace. Kernel system call traces are decoded using libipt which also provides the instruction encodings. We add support to drir_t to write these encodings to a new buffer which is re-used for all dynamic instances of that instr even across multiple system call traces.
Fixes taken/not-taken detection for conditional branches in the syscall trace.
Adds support in the syscall_mix tool to report the counts of each system call's traces also. Adds sysnum to system call trace start and end markers to achieve this.
Ran all Intel-PT tests locally:
Found some flakiness due to #6486 in local runs of the kernel sudo tests, which will be addressed separately.
Issue: #5505