Set breakpoints in libsystem_kernel. - #52
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Mic92
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May 22, 2026 16:21
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Yeah that sounds useful. |
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Searching every loaded module for breakpoints is slow. The syscall wrappers all live in a handful of system dylibs (libsystem_kernel, libsystem_c, libsystem_pthread, ...), so restrict the search to those.
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Explicitly specify the "libsystem_kernel.dylib" module when setting breakpoints. Without this, setting breakpoints by name for each syscall will end up creating a breakpoint for any method with the same name as the syscall, which can be pretty common.
For example, in a C++ program I was testing, the runtimes were:
no strace - 0.1 seconds
strace with this patch - 20 seconds
strace without this patch - 250 seconds
This was because there were thousands of calls to a method named
link(), which was not thelink(2)syscall.