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![Thiago Jung Bauermann](/assets/img/avatar_default.png)
Secure Encrypted Virtualization is an x86-specific feature, so it shouldn't appear in generic kernel code because it forces non-x86 architectures to define the sev_active() function, which doesn't make a lot of sense. To solve this problem, add an x86 elfcorehdr_read() function to override the generic weak implementation. To do that, it's necessary to make read_from_oldmem() public so that it can be used outside of vmcore.c. Also, remove the export for sev_active() since it's only used in files that won't be built as modules. Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Lianbo Jiang <lijiang@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190806044919.10622-6-bauerman@linux.ibm.com
132 lines
4 KiB
C
132 lines
4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef LINUX_CRASH_DUMP_H
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#define LINUX_CRASH_DUMP_H
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#include <linux/kexec.h>
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#include <linux/proc_fs.h>
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#include <linux/elf.h>
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#include <uapi/linux/vmcore.h>
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#include <asm/pgtable.h> /* for pgprot_t */
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#ifdef CONFIG_CRASH_DUMP
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#define ELFCORE_ADDR_MAX (-1ULL)
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#define ELFCORE_ADDR_ERR (-2ULL)
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extern unsigned long long elfcorehdr_addr;
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extern unsigned long long elfcorehdr_size;
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extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size);
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extern void elfcorehdr_free(unsigned long long addr);
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extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos);
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extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos);
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extern int remap_oldmem_pfn_range(struct vm_area_struct *vma,
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unsigned long from, unsigned long pfn,
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unsigned long size, pgprot_t prot);
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extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
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unsigned long, int);
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extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf,
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size_t csize, unsigned long offset,
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int userbuf);
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void vmcore_cleanup(void);
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/* Architecture code defines this if there are other possible ELF
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* machine types, e.g. on bi-arch capable hardware. */
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#ifndef vmcore_elf_check_arch_cross
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#define vmcore_elf_check_arch_cross(x) 0
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#endif
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/*
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* Architecture code can redefine this if there are any special checks
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* needed for 32-bit ELF or 64-bit ELF vmcores. In case of 32-bit
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* only architecture, vmcore_elf64_check_arch can be set to zero.
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*/
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#ifndef vmcore_elf32_check_arch
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#define vmcore_elf32_check_arch(x) elf_check_arch(x)
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#endif
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#ifndef vmcore_elf64_check_arch
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#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
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#endif
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/*
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* is_kdump_kernel() checks whether this kernel is booting after a panic of
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* previous kernel or not. This is determined by checking if previous kernel
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* has passed the elf core header address on command line.
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*
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* This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
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* return true if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic
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* of previous kernel.
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*/
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static inline bool is_kdump_kernel(void)
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{
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return elfcorehdr_addr != ELFCORE_ADDR_MAX;
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}
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/* is_vmcore_usable() checks if the kernel is booting after a panic and
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* the vmcore region is usable.
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*
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* This makes use of the fact that due to alignment -2ULL is not
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* a valid pointer, much in the vain of IS_ERR(), except
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* dealing directly with an unsigned long long rather than a pointer.
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*/
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static inline int is_vmcore_usable(void)
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{
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return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
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}
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/* vmcore_unusable() marks the vmcore as unusable,
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* without disturbing the logic of is_kdump_kernel()
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*/
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static inline void vmcore_unusable(void)
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{
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if (is_kdump_kernel())
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elfcorehdr_addr = ELFCORE_ADDR_ERR;
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}
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#define HAVE_OLDMEM_PFN_IS_RAM 1
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extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
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extern void unregister_oldmem_pfn_is_ram(void);
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#else /* !CONFIG_CRASH_DUMP */
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static inline bool is_kdump_kernel(void) { return 0; }
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#endif /* CONFIG_CRASH_DUMP */
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extern unsigned long saved_max_pfn;
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/* Device Dump information to be filled by drivers */
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struct vmcoredd_data {
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char dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Unique name of the dump */
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unsigned int size; /* Size of the dump */
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/* Driver's registered callback to be invoked to collect dump */
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int (*vmcoredd_callback)(struct vmcoredd_data *data, void *buf);
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};
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#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
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int vmcore_add_device_dump(struct vmcoredd_data *data);
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#else
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static inline int vmcore_add_device_dump(struct vmcoredd_data *data)
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{
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return -EOPNOTSUPP;
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}
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#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
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#ifdef CONFIG_PROC_VMCORE
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ssize_t read_from_oldmem(char *buf, size_t count,
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u64 *ppos, int userbuf,
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bool encrypted);
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#else
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static inline ssize_t read_from_oldmem(char *buf, size_t count,
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u64 *ppos, int userbuf,
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bool encrypted)
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{
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return -EOPNOTSUPP;
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}
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#endif /* CONFIG_PROC_VMCORE */
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#endif /* LINUX_CRASHDUMP_H */
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