Resolve file descriptor names #25
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This commit implement a C function that maps (pid, fd) -> path and works both on Linux and macOS. The following syscalls are augmented with the path of fd involved: * read * write * close Not yet implemented: * openat as it needs special support for CWD * all other syscalls that do not have details yet :)
nh2
reviewed
Jul 11, 2019
| #include <memory.h> | ||
| #endif | ||
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| // assert: sizeof(buf) == MAXPATHLEN |
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This precondition is cheap to check, should we check it?
| throwErrnoIfMinus1 "resolve_fd_name" (c_resolve_fd_name pid fd ptr) >>= \case | ||
| 0 -> Just <$> peekCString ptr | ||
| 1 -> pure Nothing | ||
| _ -> throwIO $ AssertionFailed "resolveFdName: something terrible happened" |
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Doesn't 2 mean "OS not supported"?
Perhaps we should explicitly say that?
| #if defined __linux__ | ||
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| char proc_path[MAXPATHLEN]; | ||
| snprintf(proc_path, MAXPATHLEN, "/proc/%d/fd/%d", pid, fd); |
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We might check for errors by checking the return value of snprintf.
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This is somewhat WIP, as it prints file paths unconditionally (i.e. no
-yflag). Not sure how bad we want it.This change is