mirror of
https://github.com/boykopovar/AnyPS5.git
synced 2026-10-22 08:33:12 -05:00
marshmll
438d410824
On Linux a guest stderr redirect also moves the host's: guest descriptors are host descriptors, and the guest stderr stream wraps the host stderr FILE. After dup2(fd, 2), or freopen(path, mode, stderr) with full buffering, the libc terminate report, the host fprintf(stderr) diagnostics and libstdc++'s terminate message go into the title's pipe or file, and abort() discards what is still buffered. RetroArch (PPSA99169) reopens stderr onto app0/trace.txt with full buffering, so its stop on main left no message anywhere. Before the first guest redirect of descriptor 2 (libkernel dup2, libc freopen of a stream on descriptor 2), keep a close-on-exec duplicate of the host descriptor 2 and point the host stderr at an unbuffered stream on it. The guest stream keeps its own FILE and follows the redirect. The libc terminate report writes to the kept descriptor with write() instead of the stderr stream, and libkernel's sceKernelDebugOutText uses the same kept descriptor.
94 lines
3.5 KiB
C++
94 lines
3.5 KiB
C++
#include "prx/libc/include/FileStream.hpp"
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#include "prx/libc/include/general/VabiMacros.hpp"
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#include <csignal>
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#include <cstdint>
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#include <cstdio>
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#include <cstdlib>
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#include <filesystem>
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#include <fstream>
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#include <iterator>
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#include <stdexcept>
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#include <string>
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#include <sys/wait.h>
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#include <unistd.h>
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extern "C" {
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FileStream* APS5_VABI freopen_nid_postfix(const char*, const char*, FileStream*);
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int APS5_VABI setvbuf_nid_postfix(FileStream*, char*, int, std::size_t);
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std::size_t APS5_VABI fwrite_nid_postfix(const void*, std::size_t, std::size_t, FileStream*);
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int APS5_VABI fflush_nid_postfix(FileStream*);
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int APS5_VABI pipe_nid_postfix(int*);
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int APS5_VABI dup2_nid_postfix(int, int);
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std::int64_t APS5_VABI write_nid_postfix(int, const void*, std::size_t);
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extern FileStream* __stderrp_nid_postfix;
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}
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static void Require(bool value) { if (!value) std::abort(); }
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enum class Redirect { Duplicate, Reopen };
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struct Outcome {
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std::string host;
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int status = 0;
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};
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static void RedirectGuest(Redirect redirect, const std::filesystem::path& probe) {
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if (redirect == Redirect::Duplicate) {
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int guest[2] = {-1, -1};
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Require(pipe_nid_postfix(guest) == 0);
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Require(dup2_nid_postfix(guest[1], 2) == 2);
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Require(write_nid_postfix(2, "guest", 5) == 5);
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return;
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}
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Require(freopen_nid_postfix(probe.c_str(), "w", __stderrp_nid_postfix) == __stderrp_nid_postfix);
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Require(setvbuf_nid_postfix(__stderrp_nid_postfix, nullptr, 0, 0) == 0);
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Require(fwrite_nid_postfix("guest", 1, 5, __stderrp_nid_postfix) == 5);
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}
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static Outcome Run(Redirect redirect, const std::filesystem::path& probe, bool terminate) {
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int host[2] = {-1, -1};
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Require(::pipe(host) == 0);
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const pid_t child = ::fork();
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Require(child >= 0);
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if (child == 0) {
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::close(host[0]);
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if (::dup2(host[1], 2) != 2) ::_exit(70);
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::close(host[1]);
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RedirectGuest(redirect, probe);
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std::fputs("host\n", stderr);
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if (terminate) throw std::runtime_error("report kept");
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if (redirect == Redirect::Reopen && fflush_nid_postfix(__stderrp_nid_postfix) != 0) ::_exit(71);
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::_exit(0);
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}
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::close(host[1]);
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Outcome outcome;
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char buffer[4096];
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for (ssize_t count; (count = ::read(host[0], buffer, sizeof(buffer))) > 0;) outcome.host.append(buffer, static_cast<std::size_t>(count));
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::close(host[0]);
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Require(::waitpid(child, &outcome.status, 0) == child);
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return outcome;
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}
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static std::string Contents(const std::filesystem::path& path) {
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std::ifstream stream(path, std::ios::binary);
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return std::string(std::istreambuf_iterator<char>(stream), std::istreambuf_iterator<char>());
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}
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int main() {
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const std::filesystem::path probe = "host_stderr_probe_" + std::to_string(::getpid()) + ".txt";
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for (const auto redirect : {Redirect::Duplicate, Redirect::Reopen}) {
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const auto written = Run(redirect, probe, false);
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Require(WIFEXITED(written.status) && WEXITSTATUS(written.status) == 0);
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Require(written.host == "host\n");
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if (redirect == Redirect::Reopen) Require(Contents(probe) == "guest");
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const auto terminated = Run(redirect, probe, true);
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Require(WIFSIGNALED(terminated.status) && WTERMSIG(terminated.status) == SIGABRT);
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Require(terminated.host.rfind("host\n", 0) == 0);
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Require(terminated.host.find(" what(): report kept\n") != std::string::npos);
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if (redirect == Redirect::Reopen) Require(Contents(probe).find("report kept") == std::string::npos);
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}
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std::filesystem::remove(probe);
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return 0;
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}
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