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-rw-r--r--arch/x86/kernel/kexec-bzimage64.c47
-rw-r--r--include/linux/kexec.h5
-rw-r--r--include/uapi/linux/kexec.h4
-rw-r--r--kernel/kexec_file.c1
4 files changed, 53 insertions, 4 deletions
diff --git a/arch/x86/kernel/kexec-bzimage64.c b/arch/x86/kernel/kexec-bzimage64.c
index 24a41f0e0cf1..c3244ac680d1 100644
--- a/arch/x86/kernel/kexec-bzimage64.c
+++ b/arch/x86/kernel/kexec-bzimage64.c
@@ -16,6 +16,8 @@
#include <linux/kexec.h>
#include <linux/kernel.h>
#include <linux/mm.h>
+#include <linux/libfdt.h>
+#include <linux/of_fdt.h>
#include <linux/efi.h>
#include <linux/random.h>
@@ -212,6 +214,28 @@ setup_efi_state(struct boot_params *params, unsigned long params_load_addr,
}
#endif /* CONFIG_EFI */
+#ifdef CONFIG_OF_FLATTREE
+static void setup_dtb(struct boot_params *params,
+ unsigned long params_load_addr,
+ unsigned int dtb_setup_data_offset)
+{
+ struct setup_data *sd = (void *)params + dtb_setup_data_offset;
+ unsigned long setup_data_phys, dtb_len;
+
+ dtb_len = fdt_totalsize(initial_boot_params);
+ sd->type = SETUP_DTB;
+ sd->len = dtb_len;
+
+ /* Carry over current boot DTB with setup_data */
+ memcpy(sd->data, initial_boot_params, dtb_len);
+
+ /* Add setup data */
+ setup_data_phys = params_load_addr + dtb_setup_data_offset;
+ sd->next = params->hdr.setup_data;
+ params->hdr.setup_data = setup_data_phys;
+}
+#endif /* CONFIG_OF_FLATTREE */
+
static void
setup_ima_state(const struct kimage *image, struct boot_params *params,
unsigned long params_load_addr,
@@ -336,6 +360,17 @@ setup_boot_parameters(struct kimage *image, struct boot_params *params,
sizeof(struct efi_setup_data);
#endif
+#ifdef CONFIG_OF_FLATTREE
+ if (image->force_dtb && initial_boot_params) {
+ setup_dtb(params, params_load_addr, setup_data_offset);
+ setup_data_offset += sizeof(struct setup_data) +
+ fdt_totalsize(initial_boot_params);
+ } else {
+ pr_debug("Not carrying over DTB, force_dtb = %d\n",
+ image->force_dtb);
+ }
+#endif
+
if (IS_ENABLED(CONFIG_IMA_KEXEC)) {
/* Setup IMA log buffer state */
setup_ima_state(image, params, params_load_addr,
@@ -529,6 +564,12 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
sizeof(struct setup_data) +
RNG_SEED_LENGTH;
+#ifdef CONFIG_OF_FLATTREE
+ if (image->force_dtb && initial_boot_params)
+ kbuf.bufsz += sizeof(struct setup_data) +
+ fdt_totalsize(initial_boot_params);
+#endif
+
if (IS_ENABLED(CONFIG_IMA_KEXEC))
kbuf.bufsz += sizeof(struct setup_data) +
sizeof(struct ima_setup_data);
@@ -537,7 +578,7 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
kbuf.bufsz += sizeof(struct setup_data) +
sizeof(struct kho_data);
- params = kzalloc(kbuf.bufsz, GFP_KERNEL);
+ params = kvzalloc(kbuf.bufsz, GFP_KERNEL);
if (!params)
return ERR_PTR(-ENOMEM);
efi_map_offset = params_cmdline_sz;
@@ -647,7 +688,7 @@ static void *bzImage64_load(struct kimage *image, char *kernel,
return ldata;
out_free_params:
- kfree(params);
+ kvfree(params);
return ERR_PTR(ret);
}
@@ -659,7 +700,7 @@ static int bzImage64_cleanup(void *loader_data)
if (!ldata)
return 0;
- kfree(ldata->bootparams_buf);
+ kvfree(ldata->bootparams_buf);
ldata->bootparams_buf = NULL;
return 0;
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 39fe3e6cd282..ff7e231b0485 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -395,6 +395,9 @@ struct kimage {
/* Information for loading purgatory */
struct purgatory_info purgatory_info;
+
+ /* Force carrying over the DTB from the current boot */
+ bool force_dtb;
#endif
#ifdef CONFIG_CRASH_HOTPLUG
@@ -461,7 +464,7 @@ bool kexec_load_permitted(int kexec_image_type);
/* List of defined/legal kexec file flags */
#define KEXEC_FILE_FLAGS (KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
KEXEC_FILE_NO_INITRAMFS | KEXEC_FILE_DEBUG | \
- KEXEC_FILE_NO_CMA)
+ KEXEC_FILE_NO_CMA | KEXEC_FILE_FORCE_DTB)
/* flag to track if kexec reboot is in progress */
extern bool kexec_in_progress;
diff --git a/include/uapi/linux/kexec.h b/include/uapi/linux/kexec.h
index 8958ebfcff94..55749cb0b81d 100644
--- a/include/uapi/linux/kexec.h
+++ b/include/uapi/linux/kexec.h
@@ -22,12 +22,16 @@
* KEXEC_FILE_ON_CRASH : Load/unload operation belongs to kdump image.
* KEXEC_FILE_NO_INITRAMFS : No initramfs is being loaded. Ignore the initrd
* fd field.
+ * KEXEC_FILE_FORCE_DTB : Force carrying over the current boot's DTB to the new
+ * kernel on x86. This is already the default behavior on
+ * some other architectures, like ARM64 and PowerPC.
*/
#define KEXEC_FILE_UNLOAD 0x00000001
#define KEXEC_FILE_ON_CRASH 0x00000002
#define KEXEC_FILE_NO_INITRAMFS 0x00000004
#define KEXEC_FILE_DEBUG 0x00000008
#define KEXEC_FILE_NO_CMA 0x00000010
+#define KEXEC_FILE_FORCE_DTB 0x00000020
/* These values match the ELF architecture values.
* Unless there is a good reason that should continue to be the case.
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 91d46502a817..eb62a9794242 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -255,6 +255,7 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
}
image->no_cma = !!(flags & KEXEC_FILE_NO_CMA);
+ image->force_dtb = flags & KEXEC_FILE_FORCE_DTB;
if (cmdline_len) {
image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len);