Contributors: 33
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Dave Young |
356 |
33.15% |
2 |
3.64% |
| Eric W. Biedermann |
145 |
13.50% |
1 |
1.82% |
| Arnd Bergmann |
114 |
10.61% |
2 |
3.64% |
| Vivek Goyal |
77 |
7.17% |
4 |
7.27% |
| Minfei Huang |
66 |
6.15% |
3 |
5.45% |
| Dominik Brodowski |
59 |
5.49% |
1 |
1.82% |
| Huang Ying |
50 |
4.66% |
4 |
7.27% |
| Mimi Zohar |
23 |
2.14% |
1 |
1.82% |
| Baoquan He |
20 |
1.86% |
1 |
1.82% |
| Andrew Morton |
18 |
1.68% |
3 |
5.45% |
| Ricardo Ribalda Delgado |
17 |
1.58% |
2 |
3.64% |
| Eric DeVolder |
15 |
1.40% |
1 |
1.82% |
| Xunlei Pang |
15 |
1.40% |
3 |
5.45% |
| Heiko Carstens |
14 |
1.30% |
1 |
1.82% |
| Linus Torvalds (pre-git) |
12 |
1.12% |
5 |
9.09% |
| Sourabh Jain |
11 |
1.02% |
1 |
1.82% |
| Zhang Yanfei |
7 |
0.65% |
2 |
3.64% |
| Russell King |
6 |
0.56% |
1 |
1.82% |
| Robin Holt |
6 |
0.56% |
1 |
1.82% |
| Matthew Garrett |
6 |
0.56% |
1 |
1.82% |
| Stéphane Eranian |
5 |
0.47% |
1 |
1.82% |
| Valentin Schneider |
5 |
0.47% |
1 |
1.82% |
| Rafael J. Wysocki |
5 |
0.47% |
3 |
5.45% |
| Ken'ichi Ohmichi |
5 |
0.47% |
1 |
1.82% |
| Pavel Tatashin |
3 |
0.28% |
1 |
1.82% |
| Peter Zijlstra |
2 |
0.19% |
1 |
1.82% |
| Fabian Frederick |
2 |
0.19% |
1 |
1.82% |
| Kees Cook |
2 |
0.19% |
1 |
1.82% |
| Philipp Stanner |
2 |
0.19% |
1 |
1.82% |
| Thomas Gleixner |
2 |
0.19% |
1 |
1.82% |
| Khalid Aziz |
2 |
0.19% |
1 |
1.82% |
| Dan Carpenter |
1 |
0.09% |
1 |
1.82% |
| Geert Uytterhoeven |
1 |
0.09% |
1 |
1.82% |
| Total |
1074 |
|
55 |
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* kexec.c - kexec_load system call
* Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com>
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/capability.h>
#include <linux/mm.h>
#include <linux/file.h>
#include <linux/security.h>
#include <linux/kexec.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/syscalls.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include "kexec_internal.h"
static int kimage_alloc_init(struct kimage **rimage, unsigned long entry,
unsigned long nr_segments,
struct kexec_segment *segments,
unsigned long flags)
{
int ret;
struct kimage *image;
bool kexec_on_panic = flags & KEXEC_ON_CRASH;
#ifdef CONFIG_CRASH_DUMP
if (kexec_on_panic) {
/* Verify we have a valid entry point */
if ((entry < phys_to_boot_phys(crashk_res.start)) ||
(entry > phys_to_boot_phys(crashk_res.end)))
return -EADDRNOTAVAIL;
}
#endif
/* Allocate and initialize a controlling structure */
image = do_kimage_alloc_init();
if (!image)
return -ENOMEM;
image->start = entry;
image->nr_segments = nr_segments;
memcpy(image->segment, segments, nr_segments * sizeof(*segments));
#ifdef CONFIG_CRASH_DUMP
if (kexec_on_panic) {
/* Enable special crash kernel control page alloc policy. */
image->control_page = crashk_res.start;
image->type = KEXEC_TYPE_CRASH;
}
#endif
ret = sanity_check_segment_list(image);
if (ret)
goto out_free_image;
/*
* Find a location for the control code buffer, and add it
* the vector of segments so that it's pages will also be
* counted as destination pages.
*/
ret = -ENOMEM;
image->control_code_page = kimage_alloc_control_pages(image,
get_order(KEXEC_CONTROL_PAGE_SIZE));
if (!image->control_code_page) {
pr_err("Could not allocate control_code_buffer\n");
goto out_free_image;
}
if (!kexec_on_panic) {
image->swap_page = kimage_alloc_control_pages(image, 0);
if (!image->swap_page) {
pr_err("Could not allocate swap buffer\n");
goto out_free_control_pages;
}
}
*rimage = image;
return 0;
out_free_control_pages:
kimage_free_page_list(&image->control_pages);
out_free_image:
kfree(image);
return ret;
}
static int do_kexec_load(unsigned long entry, unsigned long nr_segments,
struct kexec_segment *segments, unsigned long flags)
{
struct kimage **dest_image, *image;
unsigned long i;
int ret;
/*
* Because we write directly to the reserved memory region when loading
* crash kernels we need a serialization here to prevent multiple crash
* kernels from attempting to load simultaneously.
*/
if (!kexec_trylock())
return -EBUSY;
#ifdef CONFIG_CRASH_DUMP
if (flags & KEXEC_ON_CRASH) {
dest_image = &kexec_crash_image;
if (kexec_crash_image)
arch_kexec_unprotect_crashkres();
} else
#endif
dest_image = &kexec_image;
if (nr_segments == 0) {
/* Uninstall image */
kimage_free(xchg(dest_image, NULL));
ret = 0;
goto out_unlock;
}
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)
goto out_unlock;
if (flags & KEXEC_PRESERVE_CONTEXT)
image->preserve_context = 1;
#ifdef CONFIG_CRASH_HOTPLUG
if ((flags & KEXEC_ON_CRASH) && arch_crash_hotplug_support(image, flags))
image->hotplug_support = 1;
#endif
ret = machine_kexec_prepare(image);
if (ret)
goto out;
/*
* Some architecture(like S390) may touch the crash memory before
* machine_kexec_prepare(), we must copy vmcoreinfo data after it.
*/
ret = kimage_crash_copy_vmcoreinfo(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);
ret = machine_kexec_post_load(image);
if (ret)
goto out;
/* Install the new kernel and uninstall the old */
image = xchg(dest_image, image);
out:
#ifdef CONFIG_CRASH_DUMP
if ((flags & KEXEC_ON_CRASH) && kexec_crash_image)
arch_kexec_protect_crashkres();
#endif
kimage_free(image);
out_unlock:
kexec_unlock();
return ret;
}
/*
* Exec Kernel system call: for obvious reasons only root may call it.
*
* This call breaks up into three pieces.
* - A generic part which loads the new kernel from the current
* address space, and very carefully places the data in the
* allocated pages.
*
* - A generic part that interacts with the kernel and tells all of
* the devices to shut down. Preventing on-going dmas, and placing
* the devices in a consistent state so a later kernel can
* reinitialize them.
*
* - A machine specific part that includes the syscall number
* and then copies the image to it's final destination. And
* jumps into the image at entry.
*
* kexec does not sync, or unmount filesystems so if you need
* that to happen you need to do that yourself.
*/
static inline int kexec_load_check(unsigned long nr_segments,
unsigned long flags)
{
int image_type = (flags & KEXEC_ON_CRASH) ?
KEXEC_TYPE_CRASH : KEXEC_TYPE_DEFAULT;
int result;
/* We only trust the superuser with rebooting the system. */
if (!kexec_load_permitted(image_type))
return -EPERM;
/* Permit LSMs and IMA to fail the kexec */
result = security_kernel_load_data(LOADING_KEXEC_IMAGE, false);
if (result < 0)
return result;
/*
* kexec can be used to circumvent module loading restrictions, so
* prevent loading in that case
*/
result = security_locked_down(LOCKDOWN_KEXEC);
if (result)
return result;
/*
* Verify we have a legal set of flags
* This leaves us room for future extensions.
*/
if ((flags & KEXEC_FLAGS) != (flags & ~KEXEC_ARCH_MASK))
return -EINVAL;
/* Put an artificial cap on the number
* of segments passed to kexec_load.
*/
if (nr_segments > KEXEC_SEGMENT_MAX)
return -EINVAL;
return 0;
}
SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
struct kexec_segment __user *, segments, unsigned long, flags)
{
struct kexec_segment *ksegments;
unsigned long result;
result = kexec_load_check(nr_segments, flags);
if (result)
return result;
/* Verify we are on the appropriate architecture */
if (((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH) &&
((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT))
return -EINVAL;
ksegments = memdup_array_user(segments, nr_segments, sizeof(ksegments[0]));
if (IS_ERR(ksegments))
return PTR_ERR(ksegments);
result = do_kexec_load(entry, nr_segments, ksegments, flags);
kfree(ksegments);
return result;
}
#ifdef CONFIG_COMPAT
COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry,
compat_ulong_t, nr_segments,
struct compat_kexec_segment __user *, segments,
compat_ulong_t, flags)
{
struct compat_kexec_segment in;
struct kexec_segment *ksegments;
unsigned long i, result;
result = kexec_load_check(nr_segments, flags);
if (result)
return result;
/* Don't allow clients that don't understand the native
* architecture to do anything.
*/
if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT)
return -EINVAL;
ksegments = kmalloc_array(nr_segments, sizeof(ksegments[0]),
GFP_KERNEL);
if (!ksegments)
return -ENOMEM;
for (i = 0; i < nr_segments; i++) {
result = copy_from_user(&in, &segments[i], sizeof(in));
if (result)
goto fail;
ksegments[i].buf = compat_ptr(in.buf);
ksegments[i].bufsz = in.bufsz;
ksegments[i].mem = in.mem;
ksegments[i].memsz = in.memsz;
}
result = do_kexec_load(entry, nr_segments, ksegments, flags);
fail:
kfree(ksegments);
return result;
}
#endif