mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
synced 2025-09-02 08:32:55 +00:00
b753522bed
Testing kexec handover requires a kernel driver that will generate some data and preserve it with KHO on the first boot and then restore that data and verify it was preserved properly after kexec. To facilitate such test, along with the kernel driver responsible for data generation, preservation and restoration add a script that runs a kernel in a VM with a minimal /init. The /init enables KHO, loads a kernel image for kexec and runs kexec reboot. After the boot of the kexeced kernel, the driver verifies that the data was properly preserved. [rppt@kernel.org: fix section mismatch] Link: https://lkml.kernel.org/r/aIiRC8fXiOXKbPM_@kernel.org Link: https://lkml.kernel.org/r/20250727083733.2590139-1-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alexander Graf <graf@amazon.com> Cc: Changyuan Lyu <changyuanl@google.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
101 lines
1.7 KiB
C
101 lines
1.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#ifndef NOLIBC
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#include <errno.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <fcntl.h>
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#include <syscall.h>
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#include <sys/mount.h>
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#include <sys/reboot.h>
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#endif
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/* from arch/x86/include/asm/setup.h */
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#define COMMAND_LINE_SIZE 2048
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/* from include/linux/kexex.h */
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#define KEXEC_FILE_NO_INITRAMFS 0x00000004
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#define KHO_FINILIZE "/debugfs/kho/out/finalize"
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#define KERNEL_IMAGE "/kernel"
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static int mount_filesystems(void)
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{
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if (mount("debugfs", "/debugfs", "debugfs", 0, NULL) < 0)
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return -1;
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return mount("proc", "/proc", "proc", 0, NULL);
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}
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static int kho_enable(void)
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{
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const char enable[] = "1";
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int fd;
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fd = open(KHO_FINILIZE, O_RDWR);
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if (fd < 0)
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return -1;
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if (write(fd, enable, sizeof(enable)) != sizeof(enable))
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return 1;
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close(fd);
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return 0;
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}
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static long kexec_file_load(int kernel_fd, int initrd_fd,
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unsigned long cmdline_len, const char *cmdline,
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unsigned long flags)
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{
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return syscall(__NR_kexec_file_load, kernel_fd, initrd_fd, cmdline_len,
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cmdline, flags);
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}
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static int kexec_load(void)
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{
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char cmdline[COMMAND_LINE_SIZE];
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ssize_t len;
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int fd, err;
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fd = open("/proc/cmdline", O_RDONLY);
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if (fd < 0)
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return -1;
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len = read(fd, cmdline, sizeof(cmdline));
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close(fd);
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if (len < 0)
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return -1;
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/* replace \n with \0 */
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cmdline[len - 1] = 0;
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fd = open(KERNEL_IMAGE, O_RDONLY);
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if (fd < 0)
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return -1;
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err = kexec_file_load(fd, -1, len, cmdline, KEXEC_FILE_NO_INITRAMFS);
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close(fd);
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return err ? : 0;
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}
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int main(int argc, char *argv[])
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{
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if (mount_filesystems())
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goto err_reboot;
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if (kho_enable())
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goto err_reboot;
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if (kexec_load())
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goto err_reboot;
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if (reboot(RB_KEXEC))
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goto err_reboot;
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return 0;
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err_reboot:
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reboot(RB_AUTOBOOT);
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return -1;
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}
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