// SPDX-License-Identifier: GPL-2.0

#include <assert.h>
#include <fcntl.h>
#include <inttypes.h>
#include <libgen.h>
#include <limits.h>
#include <linux/coredump.h>
#include <linux/fs.h>
#include <linux/limits.h>
#include <pthread.h>
#include <string.h>
#include <sys/mount.h>
#include <poll.h>
#include <sys/epoll.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>

#include "kselftest_harness.h"
#include "../filesystems/wrappers.h"
#include "../pidfd/pidfd.h"

#include "coredump_test.h"

#define STACKDUMP_FILE "stack_values"
#define STACKDUMP_SCRIPT "stackdump"

#ifndef PAGE_SIZE
#define PAGE_SIZE 4096
#endif

FIXTURE_SETUP(coredump)
{
        FILE *file;
        int ret;

        self->pid_coredump_server = -ESRCH;
        self->fd_tmpfs_detached = -1;
        file = fopen("/proc/sys/kernel/core_pattern", "r");
        ASSERT_NE(NULL, file);

        ret = fread(self->original_core_pattern, 1, sizeof(self->original_core_pattern), file);
        ASSERT_TRUE(ret || feof(file));
        ASSERT_LT(ret, sizeof(self->original_core_pattern));

        self->original_core_pattern[ret] = '\0';
        self->fd_tmpfs_detached = create_detached_tmpfs();
        ASSERT_GE(self->fd_tmpfs_detached, 0);

        ret = fclose(file);
        ASSERT_EQ(0, ret);
}

FIXTURE_TEARDOWN(coredump)
{
        const char *reason;
        FILE *file;
        int ret, status;

        unlink(STACKDUMP_FILE);

        if (self->pid_coredump_server > 0) {
                kill(self->pid_coredump_server, SIGTERM);
                waitpid(self->pid_coredump_server, &status, 0);
        }
        unlink("/tmp/coredump.file");
        unlink("/tmp/coredump.socket");

        file = fopen("/proc/sys/kernel/core_pattern", "w");
        if (!file) {
                reason = "Unable to open core_pattern";
                goto fail;
        }

        ret = fprintf(file, "%s", self->original_core_pattern);
        if (ret < 0) {
                reason = "Unable to write to core_pattern";
                goto fail;
        }

        ret = fclose(file);
        if (ret) {
                reason = "Unable to close core_pattern";
                goto fail;
        }

        if (self->fd_tmpfs_detached >= 0) {
                ret = close(self->fd_tmpfs_detached);
                if (ret < 0) {
                        reason = "Unable to close detached tmpfs";
                        goto fail;
                }
                self->fd_tmpfs_detached = -1;
        }

        return;
fail:
        /* This should never happen */
        fprintf(stderr, "Failed to cleanup stackdump test: %s\n", reason);
}

TEST_F_TIMEOUT(coredump, stackdump, 120)
{
        unsigned long long stack;
        char *test_dir, *line;
        size_t line_length;
        char buf[PAGE_SIZE];
        int ret, i, status;
        FILE *file;
        pid_t pid;

        /*
         * Step 1: Setup core_pattern so that the stackdump script is executed when the child
         * process crashes
         */
        ret = readlink("/proc/self/exe", buf, sizeof(buf));
        ASSERT_NE(-1, ret);
        ASSERT_LT(ret, sizeof(buf));
        buf[ret] = '\0';

        test_dir = dirname(buf);

        file = fopen("/proc/sys/kernel/core_pattern", "w");
        ASSERT_NE(NULL, file);

        ret = fprintf(file, "|%1$s/%2$s %%P %1$s/%3$s", test_dir, STACKDUMP_SCRIPT, STACKDUMP_FILE);
        ASSERT_LT(0, ret);

        ret = fclose(file);
        ASSERT_EQ(0, ret);

        /* Step 2: Create a process who spawns some threads then crashes */
        pid = fork();
        ASSERT_TRUE(pid >= 0);
        if (pid == 0)
                crashing_child();

        /*
         * Step 3: Wait for the stackdump script to write the stack pointers to the stackdump file
         */
        waitpid(pid, &status, 0);
        ASSERT_TRUE(WIFSIGNALED(status));
        ASSERT_TRUE(WCOREDUMP(status));

        for (i = 0; i < 10; ++i) {
                file = fopen(STACKDUMP_FILE, "r");
                if (file)
                        break;
                sleep(1);
        }
        ASSERT_NE(file, NULL);

        /* Step 4: Make sure all stack pointer values are non-zero */
        line = NULL;
        for (i = 0; -1 != getline(&line, &line_length, file); ++i) {
                stack = strtoull(line, NULL, 10);
                ASSERT_NE(stack, 0);
        }
        free(line);

        ASSERT_EQ(i, 1 + NUM_THREAD_SPAWN);

        fclose(file);
}

TEST_HARNESS_MAIN