From 0eea08678ebe9f7d8ef98fed974a5bf1a0dd2dd2 Mon Sep 17 00:00:00 2001 From: Minfei Huang Date: Mon, 23 May 2016 16:24:19 -0700 Subject: [PATCH] kexec: do a cleanup for function kexec_load There are a lof of work to be done in function kexec_load, not only for allocating structs and loading initram, but also for some misc. To make it more clear, wrap a new function do_kexec_load which is used to allocate structs and load initram. And the pre-work will be done in kexec_load. Signed-off-by: Minfei Huang Cc: Vivek Goyal Cc: "Eric W. Biederman" Cc: Xunlei Pang Cc: Baoquan He Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kexec.c | 125 +++++++++++++++++++++++++++---------------------- 1 file changed, 69 insertions(+), 56 deletions(-) diff --git a/kernel/kexec.c b/kernel/kexec.c index 4b49aa71304f..b73dc211fcfd 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -103,6 +103,74 @@ static int kimage_alloc_init(struct kimage **rimage, unsigned long entry, return ret; } +static int do_kexec_load(unsigned long entry, unsigned long nr_segments, + struct kexec_segment __user *segments, unsigned long flags) +{ + struct kimage **dest_image, *image; + unsigned long i; + int ret; + + if (flags & KEXEC_ON_CRASH) { + dest_image = &kexec_crash_image; + if (kexec_crash_image) + arch_kexec_unprotect_crashkres(); + } else { + dest_image = &kexec_image; + } + + if (nr_segments == 0) { + /* Uninstall image */ + kimage_free(xchg(dest_image, NULL)); + return 0; + } + if (flags & KEXEC_ON_CRASH) { + /* + * Loading another kernel to switch to if this one + * crashes. Free any current crash dump kernel before + * we corrupt it. + */ + kimage_free(xchg(&kexec_crash_image, NULL)); + } + + ret = kimage_alloc_init(&image, entry, nr_segments, segments, flags); + if (ret) + return ret; + + if (flags & KEXEC_ON_CRASH) + crash_map_reserved_pages(); + + if (flags & KEXEC_PRESERVE_CONTEXT) + image->preserve_context = 1; + + ret = machine_kexec_prepare(image); + if (ret) + goto out; + + for (i = 0; i < nr_segments; i++) { + ret = kimage_load_segment(image, &image->segment[i]); + if (ret) + goto out; + } + + kimage_terminate(image); + + /* Install the new kernel and uninstall the old */ + image = xchg(dest_image, image); + +out: + if ((flags & KEXEC_ON_CRASH) && kexec_crash_image) + arch_kexec_protect_crashkres(); + + /* + * Once the reserved memory is mapped, we should unmap this memory + * before returning + */ + if (flags & KEXEC_ON_CRASH) + crash_unmap_reserved_pages(); + kimage_free(image); + return ret; +} + /* * Exec Kernel system call: for obvious reasons only root may call it. * @@ -127,7 +195,6 @@ static int kimage_alloc_init(struct kimage **rimage, unsigned long entry, SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, struct kexec_segment __user *, segments, unsigned long, flags) { - struct kimage **dest_image, *image; int result; /* We only trust the superuser with rebooting the system. */ @@ -152,9 +219,6 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, if (nr_segments > KEXEC_SEGMENT_MAX) return -EINVAL; - image = NULL; - result = 0; - /* Because we write directly to the reserved memory * region when loading crash kernels we need a mutex here to * prevent multiple crash kernels from attempting to load @@ -166,63 +230,12 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments, if (!mutex_trylock(&kexec_mutex)) return -EBUSY; - dest_image = &kexec_image; - if (flags & KEXEC_ON_CRASH) { - dest_image = &kexec_crash_image; - if (kexec_crash_image) - arch_kexec_unprotect_crashkres(); - } - - if (nr_segments > 0) { - unsigned long i; - - if (flags & KEXEC_ON_CRASH) { - /* - * Loading another kernel to switch to if this one - * crashes. Free any current crash dump kernel before - * we corrupt it. - */ - - kimage_free(xchg(&kexec_crash_image, NULL)); - result = kimage_alloc_init(&image, entry, nr_segments, - segments, flags); - crash_map_reserved_pages(); - } else { - /* Loading another kernel to reboot into. */ - - result = kimage_alloc_init(&image, entry, nr_segments, - segments, flags); - } - if (result) - goto unmap_page; - - if (flags & KEXEC_PRESERVE_CONTEXT) - image->preserve_context = 1; - result = machine_kexec_prepare(image); - if (result) - goto unmap_page; - - for (i = 0; i < nr_segments; i++) { - result = kimage_load_segment(image, &image->segment[i]); - if (result) - goto unmap_page; - } - kimage_terminate(image); -unmap_page: - if (flags & KEXEC_ON_CRASH) - crash_unmap_reserved_pages(); - if (result) - goto out; - } - /* Install the new kernel, and Uninstall the old */ - image = xchg(dest_image, image); + result = do_kexec_load(entry, nr_segments, segments, flags); -out: if ((flags & KEXEC_ON_CRASH) && kexec_crash_image) arch_kexec_protect_crashkres(); mutex_unlock(&kexec_mutex); - kimage_free(image); return result; } -- GitLab