110 lines
3.3 KiB
C
110 lines
3.3 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* powerpc code to implement the kexec_file_load syscall
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*
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* Copyright (C) 2004 Adam Litke (agl@us.ibm.com)
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* Copyright (C) 2004 IBM Corp.
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* Copyright (C) 2004,2005 Milton D Miller II, IBM Corporation
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* Copyright (C) 2005 R Sharada (sharada@in.ibm.com)
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* Copyright (C) 2006 Mohan Kumar M (mohan@in.ibm.com)
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* Copyright (C) 2016 IBM Corporation
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*
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* Based on kexec-tools' kexec-elf-ppc64.c, fs2dt.c.
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* Heavily modified for the kernel by
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* Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>.
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*/
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#include <linux/slab.h>
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#include <linux/kexec.h>
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#include <linux/of_fdt.h>
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#include <linux/libfdt.h>
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#include <asm/setup.h>
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#define SLAVE_CODE_SIZE 256 /* First 0x100 bytes */
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/**
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* setup_kdump_cmdline - Prepend "elfcorehdr=<addr> " to command line
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* of kdump kernel for exporting the core.
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* @image: Kexec image
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* @cmdline: Command line parameters to update.
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* @cmdline_len: Length of the cmdline parameters.
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*
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* kdump segment must be setup before calling this function.
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*
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* Returns new cmdline buffer for kdump kernel on success, NULL otherwise.
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*/
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char *setup_kdump_cmdline(struct kimage *image, char *cmdline,
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unsigned long cmdline_len)
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{
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int elfcorehdr_strlen;
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char *cmdline_ptr;
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cmdline_ptr = kzalloc(COMMAND_LINE_SIZE, GFP_KERNEL);
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if (!cmdline_ptr)
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return NULL;
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elfcorehdr_strlen = sprintf(cmdline_ptr, "elfcorehdr=0x%lx ",
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image->elf_load_addr);
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if (elfcorehdr_strlen + cmdline_len > COMMAND_LINE_SIZE) {
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pr_err("Appending elfcorehdr=<addr> exceeds cmdline size\n");
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kfree(cmdline_ptr);
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return NULL;
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}
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memcpy(cmdline_ptr + elfcorehdr_strlen, cmdline, cmdline_len);
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// Ensure it's nul terminated
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cmdline_ptr[COMMAND_LINE_SIZE - 1] = '\0';
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return cmdline_ptr;
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}
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/**
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* setup_purgatory - initialize the purgatory's global variables
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* @image: kexec image.
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* @slave_code: Slave code for the purgatory.
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* @fdt: Flattened device tree for the next kernel.
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* @kernel_load_addr: Address where the kernel is loaded.
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* @fdt_load_addr: Address where the flattened device tree is loaded.
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*
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* Return: 0 on success, or negative errno on error.
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*/
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int setup_purgatory(struct kimage *image, const void *slave_code,
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const void *fdt, unsigned long kernel_load_addr,
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unsigned long fdt_load_addr)
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{
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unsigned int *slave_code_buf, master_entry;
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int ret;
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slave_code_buf = kmalloc(SLAVE_CODE_SIZE, GFP_KERNEL);
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if (!slave_code_buf)
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return -ENOMEM;
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/* Get the slave code from the new kernel and put it in purgatory. */
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ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
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slave_code_buf, SLAVE_CODE_SIZE,
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true);
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if (ret) {
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kfree(slave_code_buf);
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return ret;
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}
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master_entry = slave_code_buf[0];
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memcpy(slave_code_buf, slave_code, SLAVE_CODE_SIZE);
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slave_code_buf[0] = master_entry;
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ret = kexec_purgatory_get_set_symbol(image, "purgatory_start",
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slave_code_buf, SLAVE_CODE_SIZE,
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false);
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kfree(slave_code_buf);
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ret = kexec_purgatory_get_set_symbol(image, "kernel", &kernel_load_addr,
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sizeof(kernel_load_addr), false);
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if (ret)
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return ret;
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ret = kexec_purgatory_get_set_symbol(image, "dt_offset", &fdt_load_addr,
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sizeof(fdt_load_addr), false);
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if (ret)
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return ret;
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return 0;
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}
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