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Diffstat (limited to 'kernel/kexec.c')
-rw-r--r--kernel/kexec.c120
1 files changed, 54 insertions, 66 deletions
diff --git a/kernel/kexec.c b/kernel/kexec.c
index c82c6c06f051..a6b3f96bb50c 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -19,38 +19,23 @@
#include "kexec_internal.h"
-static int copy_user_segment_list(struct kimage *image,
- unsigned long nr_segments,
- struct kexec_segment __user *segments)
-{
- int ret;
- size_t segment_bytes;
-
- /* Read in the segments */
- image->nr_segments = nr_segments;
- segment_bytes = nr_segments * sizeof(*segments);
- ret = copy_from_user(image->segment, segments, segment_bytes);
- if (ret)
- ret = -EFAULT;
-
- return ret;
-}
-
static int kimage_alloc_init(struct kimage **rimage, unsigned long entry,
unsigned long nr_segments,
- struct kexec_segment __user *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();
@@ -58,16 +43,16 @@ static int kimage_alloc_init(struct kimage **rimage, unsigned long entry,
return -ENOMEM;
image->start = entry;
+ image->nr_segments = nr_segments;
+ memcpy(image->segment, segments, nr_segments * sizeof(*segments));
- ret = copy_user_segment_list(image, nr_segments, segments);
- if (ret)
- goto out_free_image;
-
+#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)
@@ -104,24 +89,34 @@ out_free_image:
}
static int do_kexec_load(unsigned long entry, unsigned long nr_segments,
- struct kexec_segment __user *segments, unsigned long flags)
+ 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 {
+ } else
+#endif
dest_image = &kexec_image;
- }
if (nr_segments == 0) {
/* Uninstall image */
kimage_free(xchg(dest_image, NULL));
- return 0;
+ ret = 0;
+ goto out_unlock;
}
if (flags & KEXEC_ON_CRASH) {
/*
@@ -134,11 +129,16 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments,
ret = kimage_alloc_init(&image, entry, nr_segments, segments, flags);
if (ret)
- return 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;
@@ -167,10 +167,14 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments,
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;
}
@@ -198,10 +202,12 @@ out:
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 (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
+ if (!kexec_load_permitted(image_type))
return -EPERM;
/* Permit LSMs and IMA to fail the kexec */
@@ -236,7 +242,8 @@ static inline int kexec_load_check(unsigned long nr_segments,
SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
struct kexec_segment __user *, segments, unsigned long, flags)
{
- int result;
+ struct kexec_segment *ksegments;
+ unsigned long result;
result = kexec_load_check(nr_segments, flags);
if (result)
@@ -247,20 +254,12 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
((flags & KEXEC_ARCH_MASK) != KEXEC_ARCH_DEFAULT))
return -EINVAL;
- /* 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
- * simultaneously, and to prevent a crash kernel from loading
- * over the top of a in use crash kernel.
- *
- * KISS: always take the mutex.
- */
- if (!mutex_trylock(&kexec_mutex))
- return -EBUSY;
-
- result = do_kexec_load(entry, nr_segments, segments, flags);
+ ksegments = memdup_array_user(segments, nr_segments, sizeof(ksegments[0]));
+ if (IS_ERR(ksegments))
+ return PTR_ERR(ksegments);
- mutex_unlock(&kexec_mutex);
+ result = do_kexec_load(entry, nr_segments, ksegments, flags);
+ kfree(ksegments);
return result;
}
@@ -272,7 +271,7 @@ COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry,
compat_ulong_t, flags)
{
struct compat_kexec_segment in;
- struct kexec_segment out, __user *ksegments;
+ struct kexec_segment *ksegments;
unsigned long i, result;
result = kexec_load_check(nr_segments, flags);
@@ -285,37 +284,26 @@ COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry,
if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT)
return -EINVAL;
- ksegments = compat_alloc_user_space(nr_segments * sizeof(out));
+ 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)
- return -EFAULT;
+ goto fail;
- out.buf = compat_ptr(in.buf);
- out.bufsz = in.bufsz;
- out.mem = in.mem;
- out.memsz = in.memsz;
-
- result = copy_to_user(&ksegments[i], &out, sizeof(out));
- if (result)
- return -EFAULT;
+ ksegments[i].buf = compat_ptr(in.buf);
+ ksegments[i].bufsz = in.bufsz;
+ ksegments[i].mem = in.mem;
+ ksegments[i].memsz = in.memsz;
}
- /* 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
- * simultaneously, and to prevent a crash kernel from loading
- * over the top of a in use crash kernel.
- *
- * KISS: always take the mutex.
- */
- if (!mutex_trylock(&kexec_mutex))
- return -EBUSY;
-
result = do_kexec_load(entry, nr_segments, ksegments, flags);
- mutex_unlock(&kexec_mutex);
-
+fail:
+ kfree(ksegments);
return result;
}
#endif
generated by cgit (git 2.34.1) at 2025-07-24 07:58:01 +0000