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gc: clean up error handling on Darwin

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This commit is contained in:
Artemis Tosini 2024-03-30 22:21:37 -04:00
parent 1cce5759c7
commit 474ea179fb
1 changed files with 115 additions and 113 deletions
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70
src/libstore/gc.cc
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@ -330,6 +330,13 @@ Roots LocalStore::findRoots(bool censor)
typedef std::unordered_map<Path, std::unordered_set<std::string>> UncheckedRoots; typedef std::unordered_map<Path, std::unordered_set<std::string>> UncheckedRoots;
static std::string quoteRegexChars(const std::string & raw)
{
static auto specialRegex = std::regex(R"([.^$\\*+?()\[\]{}|])");
return std::regex_replace(raw, specialRegex, R"(\$&)");
}
#if __linux__
static void readProcLink(const std::string & file, UncheckedRoots & roots) static void readProcLink(const std::string & file, UncheckedRoots & roots)
{ {
constexpr auto bufsiz = PATH_MAX; constexpr auto bufsiz = PATH_MAX;
@ -348,13 +355,6 @@ static void readProcLink(const std::string & file, UncheckedRoots & roots)
.emplace(file); .emplace(file);
} }
static std::string quoteRegexChars(const std::string & raw)
{
static auto specialRegex = std::regex(R"([.^$\\*+?()\[\]{}|])");
return std::regex_replace(raw, specialRegex, R"(\$&)");
}
#if __linux__
static void readFileRoots(const char * path, UncheckedRoots & roots) static void readFileRoots(const char * path, UncheckedRoots & roots)
{ {
try { try {
@ -445,43 +445,41 @@ static void readLibprocRoots(const Path & storeDir, UncheckedRoots & unchecked)
if (pid == 0) if (pid == 0)
continue; continue;
try {
// Process cwd/root directory // Process cwd/root directory
struct proc_vnodepathinfo vnodeInfo; struct proc_vnodepathinfo vnodeInfo;
if (proc_pidinfo(pid, PROC_PIDVNODEPATHINFO, 0, &vnodeInfo, sizeof(vnodeInfo)) <= 0) { if (proc_pidinfo(pid, PROC_PIDVNODEPATHINFO, 0, &vnodeInfo, sizeof(vnodeInfo)) <= 0)
if ((errno == ESRCH) || (errno == EPERM)) continue;
throw SysError("Getting pid %1% working directory", pid); throw SysError("Getting pid %1% working directory", pid);
};
unchecked[std::string(vnodeInfo.pvi_cdir.vip_path)].emplace("{libproc/cwd}"); unchecked[std::string(vnodeInfo.pvi_cdir.vip_path)].emplace("{libproc/cwd}");
unchecked[std::string(vnodeInfo.pvi_rdir.vip_path)].emplace("{libproc/rootdir}"); unchecked[std::string(vnodeInfo.pvi_rdir.vip_path)].emplace("{libproc/rootdir}");
// File descriptors // File descriptors
int fdBufSize = proc_pidinfo(pid, PROC_PIDLISTFDS, 0, nullptr, 0); int fdBufSize = proc_pidinfo(pid, PROC_PIDLISTFDS, 0, nullptr, 0);
if (fdBufSize <= 0) { if (fdBufSize <= 0)
if ((errno == ESRCH) || (errno == EPERM)) continue;
throw SysError("Listing pid %1% file descriptors", pid); throw SysError("Listing pid %1% file descriptors", pid);
}
std::vector<struct proc_fdinfo> fds(fdBufSize / sizeof(struct proc_fdinfo)); std::vector<struct proc_fdinfo> fds(fdBufSize / sizeof(struct proc_fdinfo));
fdBufSize = proc_pidinfo(pid, PROC_PIDLISTFDS, 0, fds.data(), fds.size() * sizeof(struct proc_fdinfo)); fdBufSize = proc_pidinfo(pid, PROC_PIDLISTFDS, 0, fds.data(), fds.size() * sizeof(struct proc_fdinfo));
if (fdBufSize <= 0) { if (fdBufSize <= 0)
if ((errno == ESRCH) || (errno == EPERM)) continue;
throw SysError("Listing pid %1% file descriptors", pid); throw SysError("Listing pid %1% file descriptors", pid);
}
fds.resize(fdBufSize / sizeof(struct proc_fdinfo)); fds.resize(fdBufSize / sizeof(struct proc_fdinfo));
for (auto fd: fds) { for (auto fd: fds) {
// While there are names for other FD types, only vnodes are in the filesystem // By definition, only a vnode is on the filesystem
if (fd.proc_fdtype != PROX_FDTYPE_VNODE) if (fd.proc_fdtype != PROX_FDTYPE_VNODE)
continue; continue;
struct vnode_fdinfowithpath fdInfo; struct vnode_fdinfowithpath fdInfo;
if (proc_pidfdinfo(pid, fd.proc_fd, PROC_PIDFDVNODEPATHINFO, &fdInfo, sizeof(fdInfo)) <= 0) { if (proc_pidfdinfo(pid, fd.proc_fd, PROC_PIDFDVNODEPATHINFO, &fdInfo, sizeof(fdInfo)) <= 0)
if ((errno == ESRCH) || (errno == EPERM) || (errno == EBADF)) continue;
throw SysError("Getting pid %1% fd %2% path", pid, fd.proc_fd); throw SysError("Getting pid %1% fd %2% path", pid, fd.proc_fd);
}
unchecked[std::string(fdInfo.pvip.vip_path)].emplace("{libproc/fd}"); unchecked[std::string(fdInfo.pvip.vip_path)].emplace("{libproc/fd}");
} }
// Regions (e.g. mmapped files, executables, shared libraries) // Regions (e.g. mmapped files, executables, shared libraries)
struct proc_regionwithpathinfo regionInfo;
uint64_t nextAddr = 0; uint64_t nextAddr = 0;
while (true) { while (true) {
// Seriously, what are you doing XNU? // Seriously, what are you doing XNU?
@ -490,21 +488,26 @@ static void readLibprocRoots(const Path & storeDir, UncheckedRoots & unchecked)
// * PROC_PIDREGIONPATHINFO2 includes regions backed by a vnode // * PROC_PIDREGIONPATHINFO2 includes regions backed by a vnode
// * PROC_PIDREGIONPATHINFO3 includes regions backed by a vnode on a specified filesystem // * PROC_PIDREGIONPATHINFO3 includes regions backed by a vnode on a specified filesystem
// Only PROC_PIDREGIONPATHINFO is documented. // Only PROC_PIDREGIONPATHINFO is documented.
// Unfortunately, using it would make finding gcroots take about 50x as long // Unfortunately, using it would make finding gcroots take about 100x as long
// and tests would fail from timeout. // and tests would fail from timeout.
// According to the Frida source code, PROC_PIDREGIONPATHINFO2 has been available // According to the Frida source code, PROC_PIDREGIONPATHINFO2 has been available
// since XNU 2782.1.97 in OS X 10.10 // since XNU 2782.1.97 in OS X 10.10
// //
// This is PROC_PIDREGIONPATHINFO2 // 22 means PROC_PIDREGIONPATHINFO2
struct proc_regionwithpathinfo regionInfo;
if (proc_pidinfo(pid, 22, nextAddr, &regionInfo, sizeof(regionInfo)) <= 0) { if (proc_pidinfo(pid, 22, nextAddr, &regionInfo, sizeof(regionInfo)) <= 0) {
if ((errno == ESRCH) || (errno == EINVAL) || (errno == EPERM)) break; // PROC_PIDREGIONPATHINFO signals we're done with an error,
// so we're expected to hit this once per process
if (errno == ESRCH || errno == EINVAL) break;
throw SysError("Getting pid %1% region path", pid); throw SysError("Getting pid %1% region path", pid);
} }
unchecked[std::string(regionInfo.prp_vip.vip_path)].emplace("{libproc/region}"); unchecked[std::string(regionInfo.prp_vip.vip_path)].emplace("{libproc/region}");
nextAddr = regionInfo.prp_prinfo.pri_address + regionInfo.prp_prinfo.pri_size; nextAddr = regionInfo.prp_prinfo.pri_address + regionInfo.prp_prinfo.pri_size;
} }
// Arguments and environment variables // Arguments and environment variables
// We can't read environment variables of binaries with with entitlements unless // We can't read environment variables of binaries with with entitlements unless
// nix has the `com.apple.private.read-environment-variables` entitlement or SIP is off // nix has the `com.apple.private.read-environment-variables` entitlement or SIP is off
@ -521,7 +524,6 @@ static void readLibprocRoots(const Path & storeDir, UncheckedRoots & unchecked)
} }
std::vector<char> args(argsSize); std::vector<char> args(argsSize);
if (sysctl(sysctlName, 3, args.data(), &argsSize, nullptr, 0) < 0) { if (sysctl(sysctlName, 3, args.data(), &argsSize, nullptr, 0) < 0) {
throw SysError("Reading pid %1% arguments", pid); throw SysError("Reading pid %1% arguments", pid);
} }
@ -536,30 +538,30 @@ static void readLibprocRoots(const Path & storeDir, UncheckedRoots & unchecked)
// Per-thread working directories // Per-thread working directories
struct proc_taskallinfo taskAllInfo; struct proc_taskallinfo taskAllInfo;
if (proc_pidinfo(pid, PROC_PIDTASKALLINFO, 0, &taskAllInfo, sizeof(taskAllInfo)) <= 0) { if (proc_pidinfo(pid, PROC_PIDTASKALLINFO, 0, &taskAllInfo, sizeof(taskAllInfo)) <= 0)
if ((errno == ESRCH) || (errno == EPERM)) continue;
throw SysError("Reading pid %1% tasks", pid); throw SysError("Reading pid %1% tasks", pid);
}
// If the process doesn't have the per-thread cwd flag then we already have the // If the process doesn't have the per-thread cwd flag then we already have the
// process-wide cwd from PROC_PIDVNODEPATHINFO // process-wide cwd from PROC_PIDVNODEPATHINFO
if (taskAllInfo.pbsd.pbi_flags & PROC_FLAG_THCWD) { if (taskAllInfo.pbsd.pbi_flags & PROC_FLAG_THCWD) {
std::vector<uint64_t> tids(taskAllInfo.ptinfo.pti_threadnum); std::vector<uint64_t> tids(taskAllInfo.ptinfo.pti_threadnum);
int tidBufSize = proc_pidinfo(pid, PROC_PIDLISTTHREADS, 0, tids.data(), tids.size() * sizeof(uint64_t)); int tidBufSize = proc_pidinfo(pid, PROC_PIDLISTTHREADS, 0, tids.data(), tids.size() * sizeof(uint64_t));
if (tidBufSize <= 0) { if (tidBufSize <= 0)
if ((errno == ESRCH) || (errno == EPERM)) continue;
throw SysError("Listing pid %1% threads", pid); throw SysError("Listing pid %1% threads", pid);
}
for (auto tid: tids) { for (auto tid: tids) {
struct proc_threadwithpathinfo threadPathInfo; struct proc_threadwithpathinfo threadPathInfo;
if (proc_pidinfo(pid, PROC_PIDTHREADPATHINFO, tid, &threadPathInfo, sizeof(threadPathInfo)) <= 0) { if (proc_pidinfo(pid, PROC_PIDTHREADPATHINFO, tid, &threadPathInfo, sizeof(threadPathInfo)) <= 0)
if ((errno == ESRCH) || (errno == EPERM)) continue;
throw SysError("Reading pid %1% thread %2% cwd", pid, tid); throw SysError("Reading pid %1% thread %2% cwd", pid, tid);
}
unchecked[std::string(threadPathInfo.pvip.vip_path)].emplace("{libproc/threadcwd}"); unchecked[std::string(threadPathInfo.pvip.vip_path)].emplace("{libproc/threadcwd}");
} }
} }
} catch (SysError & e) {
if (errno == ENOENT || errno == EACCES || errno == ESRCH)
continue;
throw;
}
} }
} }
#endif #endif