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Message-Id: <20180212100754.55121-16-prudo@linux.vnet.ibm.com>
Date: Mon, 12 Feb 2018 11:07:52 +0100
From: Philipp Rudo <prudo@...ux.vnet.ibm.com>
To: kexec@...ts.infradead.org, linux-s390@...r.kernel.org
Cc: linux-kernel@...r.kernel.org,
Eric Biederman <ebiederm@...ssion.com>,
Vivek Goyal <vgoyal@...hat.com>,
Michael Ellerman <mpe@...erman.id.au>,
Thiago Jung Bauermann <bauerman@...ux.vnet.ibm.com>,
Martin Schwidefsky <schwidefsky@...ibm.com>,
Heiko Carstens <heiko.carstens@...ibm.com>,
Andrew Morton <akpm@...ux-foundation.org>, x86@...nel.org
Subject: [PATCH 15/17] s390/kexec_file: Add image loader
Add an image loader for kexec_file_load. For simplicity first skip crash
support. The functions defined in machine_kexec_file will later be shared
with the ELF loader.
Signed-off-by: Philipp Rudo <prudo@...ux.vnet.ibm.com>
Reviewed-by: Martin Schwidefsky <schwidefsky@...ibm.com>
---
arch/s390/include/asm/kexec.h | 22 ++++++++++
arch/s390/kernel/Makefile | 2 +-
arch/s390/kernel/kexec_image.c | 80 +++++++++++++++++++++++++++++++++++
arch/s390/kernel/machine_kexec_file.c | 73 ++++++++++++++++++++++++++++++++
4 files changed, 176 insertions(+), 1 deletion(-)
create mode 100644 arch/s390/kernel/kexec_image.c
diff --git a/arch/s390/include/asm/kexec.h b/arch/s390/include/asm/kexec.h
index 1d708a419326..532f5e4f198f 100644
--- a/arch/s390/include/asm/kexec.h
+++ b/arch/s390/include/asm/kexec.h
@@ -46,4 +46,26 @@
static inline void crash_setup_regs(struct pt_regs *newregs,
struct pt_regs *oldregs) { }
+struct kimage;
+struct s390_load_data {
+ /* Pointer to the kernel buffer. Used to register cmdline etc.. */
+ void *kernel_buf;
+
+ /* Total size of loaded segments in memory. Used as an offset. */
+ size_t memsz;
+
+ /* Load address of initrd. Used to register INITRD_START in kernel. */
+ unsigned long initrd_load_addr;
+};
+
+int kexec_file_add_purgatory(struct kimage *image,
+ struct s390_load_data *data);
+int kexec_file_add_initrd(struct kimage *image,
+ struct s390_load_data *data,
+ char *initrd, unsigned long initrd_len);
+void kexec_file_update_kernel(struct kimage *iamge,
+ struct s390_load_data *data);
+
+extern const struct kexec_file_ops s390_kexec_image_ops;
+
#endif /*_S390_KEXEC_H */
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 496d4711c186..58a590709cc3 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -60,7 +60,7 @@ obj-y += debug.o irq.o ipl.o dis.o diag.o vdso.o als.o
obj-y += sysinfo.o jump_label.o lgr.o os_info.o machine_kexec.o pgm_check.o
obj-y += runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o
obj-y += entry.o reipl.o relocate_kernel.o kdebugfs.o alternative.o
-obj-y += machine_kexec_file.o
+obj-y += machine_kexec_file.o kexec_image.o
extra-y += head.o head64.o vmlinux.lds
diff --git a/arch/s390/kernel/kexec_image.c b/arch/s390/kernel/kexec_image.c
new file mode 100644
index 000000000000..83cf5a9be3a4
--- /dev/null
+++ b/arch/s390/kernel/kexec_image.c
@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Image loader for kexec_file_load system call.
+ *
+ * Copyright IBM Corp. 2018
+ *
+ * Author(s): Philipp Rudo <prudo@...ux.vnet.ibm.com>
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/kexec.h>
+#include <asm/setup.h>
+
+static int kexec_file_add_image_kernel(struct kimage *image,
+ struct s390_load_data *data,
+ char *kernel, unsigned long kernel_len)
+{
+ struct kexec_buf buf;
+ int ret;
+
+ buf.image = image;
+
+ buf.buffer = kernel + STARTUP_NORMAL_OFFSET;
+ buf.bufsz = kernel_len - STARTUP_NORMAL_OFFSET;
+
+ buf.mem = STARTUP_NORMAL_OFFSET;
+ buf.memsz = buf.bufsz;
+
+ ret = kexec_add_buffer(&buf);
+
+ data->kernel_buf = kernel;
+ data->memsz += buf.memsz + STARTUP_NORMAL_OFFSET;
+
+ return ret;
+}
+
+static void *s390_image_load(struct kimage *image,
+ char *kernel, unsigned long kernel_len,
+ char *initrd, unsigned long initrd_len,
+ char *cmdline, unsigned long cmdline_len)
+{
+ struct s390_load_data data = {0};
+ int ret;
+
+ /* We don't support crash kernels yet. */
+ if (image->type == KEXEC_TYPE_CRASH)
+ return ERR_PTR(-ENOTSUPP);
+
+ ret = kexec_file_add_image_kernel(image, &data, kernel, kernel_len);
+ if (ret)
+ return ERR_PTR(ret);
+
+ if (initrd) {
+ ret = kexec_file_add_initrd(image, &data, initrd, initrd_len);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+
+ ret = kexec_file_add_purgatory(image, &data);
+ if (ret)
+ return ERR_PTR(ret);
+
+ kexec_file_update_kernel(image, &data);
+
+ return NULL;
+}
+
+static int s390_image_probe(const char *buf, unsigned long len)
+{
+ /* Can't reliably tell if an image is valid. Therefore give the
+ * user whatever he wants.
+ */
+ return 0;
+}
+
+const struct kexec_file_ops s390_kexec_image_ops = {
+ .probe = s390_image_probe,
+ .load = s390_image_load,
+};
diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c
index e6928cbed524..052640220361 100644
--- a/arch/s390/kernel/machine_kexec_file.c
+++ b/arch/s390/kernel/machine_kexec_file.c
@@ -12,9 +12,82 @@
#include <asm/setup.h>
const struct kexec_file_ops * const kexec_file_loaders[] = {
+ &s390_kexec_image_ops,
NULL,
};
+void kexec_file_update_kernel(struct kimage *image,
+ struct s390_load_data *data)
+{
+ unsigned long *loc;
+
+ /* Callers guarantee cmdline to be \0-terminated and
+ * cmdline_len < ARCH_COMMAND_LINE_SIZE.
+ */
+ if (image->cmdline_buf_len)
+ memcpy(data->kernel_buf + COMMAND_LINE_OFFSET,
+ image->cmdline_buf, image->cmdline_buf_len);
+
+ if (image->initrd_buf) {
+ loc = (unsigned long *)(data->kernel_buf + INITRD_START_OFFSET);
+ *loc = data->initrd_load_addr;
+
+ loc = (unsigned long *)(data->kernel_buf + INITRD_SIZE_OFFSET);
+ *loc = image->initrd_buf_len;
+ }
+}
+
+static int kexec_file_update_purgatory(struct kimage *image)
+{
+ u64 entry, type;
+ int ret;
+
+ entry = STARTUP_NORMAL_OFFSET;
+ ret = kexec_purgatory_get_set_symbol(image, "kernel_entry", &entry,
+ sizeof(entry), false);
+ return ret;
+}
+
+int kexec_file_add_purgatory(struct kimage *image, struct s390_load_data *data)
+{
+ struct kexec_buf buf;
+ int ret;
+
+ buf.image = image;
+
+ data->memsz = ALIGN(data->memsz, PAGE_SIZE);
+ buf.mem = data->memsz;
+
+ ret = kexec_load_purgatory(image, &buf);
+ if (ret)
+ return ret;
+
+ ret = kexec_file_update_purgatory(image);
+ return ret;
+}
+
+int kexec_file_add_initrd(struct kimage *image, struct s390_load_data *data,
+ char *initrd, unsigned long initrd_len)
+{
+ struct kexec_buf buf;
+ int ret;
+
+ buf.image = image;
+
+ buf.buffer = initrd;
+ buf.bufsz = initrd_len;
+
+ data->memsz = ALIGN(data->memsz, PAGE_SIZE);
+ buf.mem = data->memsz;
+ buf.memsz = buf.bufsz;
+
+ data->initrd_load_addr = buf.mem;
+ data->memsz += buf.memsz;
+
+ ret = kexec_add_buffer(&buf);
+ return ret;
+}
+
/*
* The kernel is loaded to a fixed location. Turn off kexec_locate_mem_hole
* and provide kbuf->mem by hand.
--
2.13.5
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