83e3e89d66
[ Upstream commit ffc8599aa9763f39f6736a79da4d1575e7006f9a ]
On machines where the GART aperture is mapped over physical RAM,
/proc/kcore contains the GART aperture range. Accessing the GART range via
/proc/kcore results in a kernel crash.
vmcore used to have the same issue, until it was fixed with commit
2a3e83c6f9 ("x86/gart: Exclude GART aperture from vmcore")', leveraging
existing hook infrastructure in vmcore to let /proc/vmcore return zeroes
when attempting to read the aperture region, and so it won't read from the
actual memory.
Apply the same workaround for kcore. First implement the same hook
infrastructure for kcore, then reuse the hook functions introduced in the
previous vmcore fix. Just with some minor adjustment, rename some functions
for more general usage, and simplify the hook infrastructure a bit as there
is no module usage yet.
Suggested-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Kairui Song <kasong@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jiri Bohac <jbohac@suse.cz>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Dave Young <dyoung@redhat.com>
Link: https://lkml.kernel.org/r/20190308030508.13548-1-kasong@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
62 lines
1.2 KiB
C
62 lines
1.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* /proc/kcore definitions
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*/
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#ifndef _LINUX_KCORE_H
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#define _LINUX_KCORE_H
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enum kcore_type {
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KCORE_TEXT,
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KCORE_VMALLOC,
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KCORE_RAM,
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KCORE_VMEMMAP,
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KCORE_USER,
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KCORE_OTHER,
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KCORE_REMAP,
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};
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struct kcore_list {
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struct list_head list;
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unsigned long addr;
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unsigned long vaddr;
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size_t size;
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int type;
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};
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struct vmcore {
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struct list_head list;
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unsigned long long paddr;
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unsigned long long size;
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loff_t offset;
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};
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struct vmcoredd_node {
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struct list_head list; /* List of dumps */
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void *buf; /* Buffer containing device's dump */
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unsigned int size; /* Size of the buffer */
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};
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#ifdef CONFIG_PROC_KCORE
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void __init kclist_add(struct kcore_list *, void *, size_t, int type);
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static inline
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void kclist_add_remap(struct kcore_list *m, void *addr, void *vaddr, size_t sz)
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{
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m->vaddr = (unsigned long)vaddr;
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kclist_add(m, addr, sz, KCORE_REMAP);
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}
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extern int __init register_mem_pfn_is_ram(int (*fn)(unsigned long pfn));
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#else
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static inline
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void kclist_add(struct kcore_list *new, void *addr, size_t size, int type)
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{
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}
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static inline
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void kclist_add_remap(struct kcore_list *m, void *addr, void *vaddr, size_t sz)
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{
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}
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#endif
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#endif /* _LINUX_KCORE_H */
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