crash_dump: Remove no longer used saved_max_pfn (4c5b566c) · Commits · 戴 / test

saved_max_pfn was originally introduced in commit ("[PATCH] kdump: Retrieve saved max pfn") It used to make sure that the user does not try to read the physical memory beyond saved_max_pfn. But since commit ("vmcore: remove saved_max_pfn check") it's no longer used for the check. This variable doesn't have any users anymore so just remove it. [ bp: Drop the Calgary IOMMU reference from the commit message. ] Signed-off-by:

Kairui Song <kasong@redhat.com> Signed-off-by:

Borislav Petkov <bp@suse.de> Acked-by:

"Eric W. Biederman" <ebiederm@xmission.com> Link: https://lkml.kernel.org/r/20200330181544.1595733-1-kasong@redhat.com

arch/x86/kernel/e820.c

+0 −8

Original line number	Diff line number	Diff line
		@@ -910,14 +910,6 @@ static int __init parse_memmap_one(char *p)
		return -EINVAL;

		if (!strncmp(p, "exactmap", 8)) {
		#ifdef CONFIG_CRASH_DUMP
		/*
		* If we are doing a crash dump, we still need to know
		* the real memory size before the original memory map is
		* reset.
		*/
		saved_max_pfn = e820__end_of_ram_pfn();
		#endif
		e820_table->nr_entries = 0;
		userdef = 1;
		return 0;

include/linux/crash_dump.h

+0 −2

Original line number	Diff line number	Diff line
		@@ -97,8 +97,6 @@ extern void unregister_oldmem_pfn_is_ram(void);
		static inline bool is_kdump_kernel(void) { return 0; }
		#endif /* CONFIG_CRASH_DUMP */

		extern unsigned long saved_max_pfn;

		/* Device Dump information to be filled by drivers */
		struct vmcoredd_data {
		char dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Unique name of the dump */

kernel/crash_dump.c

+0 −6

Original line number	Diff line number	Diff line
		@@ -5,12 +5,6 @@
		#include <linux/errno.h>
		#include <linux/export.h>

		/*
		* If we have booted due to a crash, max_pfn will be a very low value. We need
		* to know the amount of memory that the previous kernel used.
		*/
		unsigned long saved_max_pfn;

		/*
		* stores the physical address of elf header of crash image
		*

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