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[lldb] Respect LaunchInfo::SetExecutable in ProcessLauncherPosixFork #133093

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Merged
merged 1 commit into from
Mar 27, 2025
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[lldb] Respect LaunchInfo::SetExecutable in ProcessLauncherPosixFork #133093

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8 changes: 6 additions & 2 deletions lldb/source/Host/posix/ProcessLauncherPosixFork.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -94,6 +94,7 @@ struct ForkLaunchInfo {
bool debug;
bool disable_aslr;
std::string wd;
std::string executable;
Comment on lines 96 to +97
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This is consistent with the rest of the file, but any reason these are std::strings and not FileSpecs?

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They are accessed from the forked process (line 34 in this file), so they need to be async-signal safe (nothing really guarantees std::string is that, but it's pretty hard to write a c_str implementation that isn't).

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Makes sense, thanks for explaining!

const char **argv;
Environment::Envp envp;
std::vector<ForkFileAction> actions;
Expand Down Expand Up @@ -194,7 +195,8 @@ struct ForkLaunchInfo {
}

// Execute. We should never return...
execve(info.argv[0], const_cast<char *const *>(info.argv), info.envp);
execve(info.executable.c_str(), const_cast<char *const *>(info.argv),
info.envp);

#if defined(__linux__)
if (errno == ETXTBSY) {
Expand All @@ -207,7 +209,8 @@ struct ForkLaunchInfo {
// Since this state should clear up quickly, wait a while and then give it
// one more go.
usleep(50000);
execve(info.argv[0], const_cast<char *const *>(info.argv), info.envp);
execve(info.executable.c_str(), const_cast<char *const *>(info.argv),
info.envp);
}
#endif

Expand Down Expand Up @@ -236,6 +239,7 @@ ForkLaunchInfo::ForkLaunchInfo(const ProcessLaunchInfo &info)
debug(info.GetFlags().Test(eLaunchFlagDebug)),
disable_aslr(info.GetFlags().Test(eLaunchFlagDisableASLR)),
wd(info.GetWorkingDirectory().GetPath()),
executable(info.GetExecutableFile().GetPath()),
argv(info.GetArguments().GetConstArgumentVector()),
envp(info.GetEnvironment().getEnvp()), actions(MakeForkActions(info)) {}

Expand Down
43 changes: 42 additions & 1 deletion lldb/unittests/Host/HostTest.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -7,12 +7,24 @@
//===----------------------------------------------------------------------===//

#include "lldb/Host/Host.h"
#include "TestingSupport/SubsystemRAII.h"
#include "lldb/Host/FileSystem.h"
#include "lldb/Host/ProcessLaunchInfo.h"
#include "lldb/Utility/ProcessInfo.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Testing/Support/Error.h"
#include "gtest/gtest.h"
#include <future>

using namespace lldb_private;
using namespace llvm;

// From TestMain.cpp.
extern const char *TestMainArgv0;

static cl::opt<uint64_t> test_arg("test-arg");

TEST(Host, WaitStatusFormat) {
EXPECT_EQ("W01", formatv("{0:g}", WaitStatus{WaitStatus::Exit, 1}).str());
EXPECT_EQ("X02", formatv("{0:g}", WaitStatus{WaitStatus::Signal, 2}).str());
Expand Down Expand Up @@ -45,4 +57,33 @@ TEST(Host, ProcessInstanceInfoCumulativeSystemTimeIsValid) {
EXPECT_TRUE(info.CumulativeSystemTimeIsValid());
info.SetCumulativeSystemTime(ProcessInstanceInfo::timespec{1, 0});
EXPECT_TRUE(info.CumulativeSystemTimeIsValid());
}
}

TEST(Host, LaunchProcessSetsArgv0) {
SubsystemRAII<FileSystem> subsystems;

static constexpr StringLiteral TestArgv0 = "HelloArgv0";
if (test_arg != 0) {
// In subprocess
if (TestMainArgv0 != TestArgv0) {
errs() << formatv("Got '{0}' for argv[0]\n", TestMainArgv0);
exit(1);
}
exit(0);
}

ProcessLaunchInfo info;
info.SetExecutableFile(
FileSpec(llvm::sys::fs::getMainExecutable(TestMainArgv0, &test_arg)),
/*add_exe_file_as_first_arg=*/false);
info.GetArguments().AppendArgument("HelloArgv0");
info.GetArguments().AppendArgument(
"--gtest_filter=Host.LaunchProcessSetsArgv0");
info.GetArguments().AppendArgument("--test-arg=47");
std::promise<int> exit_status;
info.SetMonitorProcessCallback([&](lldb::pid_t pid, int signal, int status) {
exit_status.set_value(status);
});
ASSERT_THAT_ERROR(Host::LaunchProcess(info).takeError(), Succeeded());
ASSERT_THAT(exit_status.get_future().get(), 0);
}