|  | // Copyright 2019 The Go Authors. All rights reserved. | 
|  | // Use of this source code is governed by a BSD-style | 
|  | // license that can be found in the LICENSE file. | 
|  |  | 
|  | //go:build linux && cgo | 
|  | // +build linux,cgo | 
|  |  | 
|  | package cgotest | 
|  |  | 
|  | import ( | 
|  | "fmt" | 
|  | "os" | 
|  | "sort" | 
|  | "strings" | 
|  | "syscall" | 
|  | "testing" | 
|  | ) | 
|  |  | 
|  | // #include <stdio.h> | 
|  | // #include <stdlib.h> | 
|  | // #include <pthread.h> | 
|  | // #include <unistd.h> | 
|  | // #include <sys/types.h> | 
|  | // | 
|  | // pthread_t *t = NULL; | 
|  | // pthread_mutex_t mu; | 
|  | // int nts = 0; | 
|  | // int all_done = 0; | 
|  | // | 
|  | // static void *aFn(void *vargp) { | 
|  | //   int done = 0; | 
|  | //   while (!done) { | 
|  | //     usleep(100); | 
|  | //     pthread_mutex_lock(&mu); | 
|  | //     done = all_done; | 
|  | //     pthread_mutex_unlock(&mu); | 
|  | //   } | 
|  | //   return NULL; | 
|  | // } | 
|  | // | 
|  | // void trial(int argc) { | 
|  | //   int i; | 
|  | //   nts = argc; | 
|  | //   t = calloc(nts, sizeof(pthread_t)); | 
|  | //   pthread_mutex_init(&mu, NULL); | 
|  | //   for (i = 0; i < nts; i++) { | 
|  | //     pthread_create(&t[i], NULL, aFn, NULL); | 
|  | //   } | 
|  | // } | 
|  | // | 
|  | // void cleanup(void) { | 
|  | //   int i; | 
|  | //   pthread_mutex_lock(&mu); | 
|  | //   all_done = 1; | 
|  | //   pthread_mutex_unlock(&mu); | 
|  | //   for (i = 0; i < nts; i++) { | 
|  | //     pthread_join(t[i], NULL); | 
|  | //   } | 
|  | //   pthread_mutex_destroy(&mu); | 
|  | //   free(t); | 
|  | // } | 
|  | import "C" | 
|  |  | 
|  | // compareStatus is used to confirm the contents of the thread | 
|  | // specific status files match expectations. | 
|  | func compareStatus(filter, expect string) error { | 
|  | expected := filter + expect | 
|  | pid := syscall.Getpid() | 
|  | fs, err := os.ReadDir(fmt.Sprintf("/proc/%d/task", pid)) | 
|  | if err != nil { | 
|  | return fmt.Errorf("unable to find %d tasks: %v", pid, err) | 
|  | } | 
|  | expectedProc := fmt.Sprintf("Pid:\t%d", pid) | 
|  | foundAThread := false | 
|  | for _, f := range fs { | 
|  | tf := fmt.Sprintf("/proc/%s/status", f.Name()) | 
|  | d, err := os.ReadFile(tf) | 
|  | if err != nil { | 
|  | // There are a surprising number of ways this | 
|  | // can error out on linux.  We've seen all of | 
|  | // the following, so treat any error here as | 
|  | // equivalent to the "process is gone": | 
|  | //    os.IsNotExist(err), | 
|  | //    "... : no such process", | 
|  | //    "... : bad file descriptor. | 
|  | continue | 
|  | } | 
|  | lines := strings.Split(string(d), "\n") | 
|  | for _, line := range lines { | 
|  | // Different kernel vintages pad differently. | 
|  | line = strings.TrimSpace(line) | 
|  | if strings.HasPrefix(line, "Pid:\t") { | 
|  | // On loaded systems, it is possible | 
|  | // for a TID to be reused really | 
|  | // quickly. As such, we need to | 
|  | // validate that the thread status | 
|  | // info we just read is a task of the | 
|  | // same process PID as we are | 
|  | // currently running, and not a | 
|  | // recently terminated thread | 
|  | // resurfaced in a different process. | 
|  | if line != expectedProc { | 
|  | break | 
|  | } | 
|  | // Fall through in the unlikely case | 
|  | // that filter at some point is | 
|  | // "Pid:\t". | 
|  | } | 
|  | if strings.HasPrefix(line, filter) { | 
|  | if line == expected { | 
|  | foundAThread = true | 
|  | break | 
|  | } | 
|  | if filter == "Groups:" && strings.HasPrefix(line, "Groups:\t") { | 
|  | // https://github.com/golang/go/issues/46145 | 
|  | // Containers don't reliably output this line in sorted order so manually sort and compare that. | 
|  | a := strings.Split(line[8:], " ") | 
|  | sort.Strings(a) | 
|  | got := strings.Join(a, " ") | 
|  | if got == expected[8:] { | 
|  | foundAThread = true | 
|  | break | 
|  | } | 
|  |  | 
|  | } | 
|  | return fmt.Errorf("%q got:%q want:%q (bad) [pid=%d file:'%s' %v]\n", tf, line, expected, pid, string(d), expectedProc) | 
|  | } | 
|  | } | 
|  | } | 
|  | if !foundAThread { | 
|  | return fmt.Errorf("found no thread /proc/<TID>/status files for process %q", expectedProc) | 
|  | } | 
|  | return nil | 
|  | } | 
|  |  | 
|  | // test1435 test 9 glibc implemented setuid/gid syscall functions are | 
|  | // mapped.  This test is a slightly more expansive test than that of | 
|  | // src/syscall/syscall_linux_test.go:TestSetuidEtc() insofar as it | 
|  | // launches concurrent threads from C code via CGo and validates that | 
|  | // they are subject to the system calls being tested. For the actual | 
|  | // Go functionality being tested here, the syscall_linux_test version | 
|  | // is considered authoritative, but non-trivial improvements to that | 
|  | // should be mirrored here. | 
|  | func test1435(t *testing.T) { | 
|  | if syscall.Getuid() != 0 { | 
|  | t.Skip("skipping root only test") | 
|  | } | 
|  |  | 
|  | // Launch some threads in C. | 
|  | const cts = 5 | 
|  | C.trial(cts) | 
|  | defer C.cleanup() | 
|  |  | 
|  | vs := []struct { | 
|  | call           string | 
|  | fn             func() error | 
|  | filter, expect string | 
|  | }{ | 
|  | {call: "Setegid(1)", fn: func() error { return syscall.Setegid(1) }, filter: "Gid:", expect: "\t0\t1\t0\t1"}, | 
|  | {call: "Setegid(0)", fn: func() error { return syscall.Setegid(0) }, filter: "Gid:", expect: "\t0\t0\t0\t0"}, | 
|  |  | 
|  | {call: "Seteuid(1)", fn: func() error { return syscall.Seteuid(1) }, filter: "Uid:", expect: "\t0\t1\t0\t1"}, | 
|  | {call: "Setuid(0)", fn: func() error { return syscall.Setuid(0) }, filter: "Uid:", expect: "\t0\t0\t0\t0"}, | 
|  |  | 
|  | {call: "Setgid(1)", fn: func() error { return syscall.Setgid(1) }, filter: "Gid:", expect: "\t1\t1\t1\t1"}, | 
|  | {call: "Setgid(0)", fn: func() error { return syscall.Setgid(0) }, filter: "Gid:", expect: "\t0\t0\t0\t0"}, | 
|  |  | 
|  | {call: "Setgroups([]int{0,1,2,3})", fn: func() error { return syscall.Setgroups([]int{0, 1, 2, 3}) }, filter: "Groups:", expect: "\t0 1 2 3"}, | 
|  | {call: "Setgroups(nil)", fn: func() error { return syscall.Setgroups(nil) }, filter: "Groups:", expect: ""}, | 
|  | {call: "Setgroups([]int{0})", fn: func() error { return syscall.Setgroups([]int{0}) }, filter: "Groups:", expect: "\t0"}, | 
|  |  | 
|  | {call: "Setregid(101,0)", fn: func() error { return syscall.Setregid(101, 0) }, filter: "Gid:", expect: "\t101\t0\t0\t0"}, | 
|  | {call: "Setregid(0,102)", fn: func() error { return syscall.Setregid(0, 102) }, filter: "Gid:", expect: "\t0\t102\t102\t102"}, | 
|  | {call: "Setregid(0,0)", fn: func() error { return syscall.Setregid(0, 0) }, filter: "Gid:", expect: "\t0\t0\t0\t0"}, | 
|  |  | 
|  | {call: "Setreuid(1,0)", fn: func() error { return syscall.Setreuid(1, 0) }, filter: "Uid:", expect: "\t1\t0\t0\t0"}, | 
|  | {call: "Setreuid(0,2)", fn: func() error { return syscall.Setreuid(0, 2) }, filter: "Uid:", expect: "\t0\t2\t2\t2"}, | 
|  | {call: "Setreuid(0,0)", fn: func() error { return syscall.Setreuid(0, 0) }, filter: "Uid:", expect: "\t0\t0\t0\t0"}, | 
|  |  | 
|  | {call: "Setresgid(101,0,102)", fn: func() error { return syscall.Setresgid(101, 0, 102) }, filter: "Gid:", expect: "\t101\t0\t102\t0"}, | 
|  | {call: "Setresgid(0,102,101)", fn: func() error { return syscall.Setresgid(0, 102, 101) }, filter: "Gid:", expect: "\t0\t102\t101\t102"}, | 
|  | {call: "Setresgid(0,0,0)", fn: func() error { return syscall.Setresgid(0, 0, 0) }, filter: "Gid:", expect: "\t0\t0\t0\t0"}, | 
|  |  | 
|  | {call: "Setresuid(1,0,2)", fn: func() error { return syscall.Setresuid(1, 0, 2) }, filter: "Uid:", expect: "\t1\t0\t2\t0"}, | 
|  | {call: "Setresuid(0,2,1)", fn: func() error { return syscall.Setresuid(0, 2, 1) }, filter: "Uid:", expect: "\t0\t2\t1\t2"}, | 
|  | {call: "Setresuid(0,0,0)", fn: func() error { return syscall.Setresuid(0, 0, 0) }, filter: "Uid:", expect: "\t0\t0\t0\t0"}, | 
|  | } | 
|  |  | 
|  | for i, v := range vs { | 
|  | if err := v.fn(); err != nil { | 
|  | t.Errorf("[%d] %q failed: %v", i, v.call, err) | 
|  | continue | 
|  | } | 
|  | if err := compareStatus(v.filter, v.expect); err != nil { | 
|  | t.Errorf("[%d] %q comparison: %v", i, v.call, err) | 
|  | } | 
|  | } | 
|  | } |