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| author | Magnus Damm <magnus@valinux.co.jp> | 2006-09-26 10:52:38 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2006-09-26 10:52:38 +0200 |
| commit | 4bfaaef01a1badb9e8ffb0c0a37cd2379008d21f (patch) | |
| tree | 652effe9d02c80d93357512233f4ee962320ac3b /include/asm-x86_64 | |
| parent | f574164491d00d28b727d713685fb5edc9138200 (diff) | |
| download | lwn-4bfaaef01a1badb9e8ffb0c0a37cd2379008d21f.tar.gz lwn-4bfaaef01a1badb9e8ffb0c0a37cd2379008d21f.zip | |
[PATCH] Avoid overwriting the current pgd (V4, x86_64)
kexec: Avoid overwriting the current pgd (V4, x86_64)
This patch upgrades the x86_64-specific kexec code to avoid overwriting the
current pgd. Overwriting the current pgd is bad when CONFIG_CRASH_DUMP is used
to start a secondary kernel that dumps the memory of the previous kernel.
The code introduces a new set of page tables. These tables are used to provide
an executable identity mapping without overwriting the current pgd.
Signed-off-by: Magnus Damm <magnus@valinux.co.jp>
Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'include/asm-x86_64')
| -rw-r--r-- | include/asm-x86_64/kexec.h | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/include/asm-x86_64/kexec.h b/include/asm-x86_64/kexec.h index c564bae03433..5fab957e1091 100644 --- a/include/asm-x86_64/kexec.h +++ b/include/asm-x86_64/kexec.h @@ -1,6 +1,27 @@ #ifndef _X86_64_KEXEC_H #define _X86_64_KEXEC_H +#define PA_CONTROL_PAGE 0 +#define VA_CONTROL_PAGE 1 +#define PA_PGD 2 +#define VA_PGD 3 +#define PA_PUD_0 4 +#define VA_PUD_0 5 +#define PA_PMD_0 6 +#define VA_PMD_0 7 +#define PA_PTE_0 8 +#define VA_PTE_0 9 +#define PA_PUD_1 10 +#define VA_PUD_1 11 +#define PA_PMD_1 12 +#define VA_PMD_1 13 +#define PA_PTE_1 14 +#define VA_PTE_1 15 +#define PA_TABLE_PAGE 16 +#define PAGES_NR 17 + +#ifndef __ASSEMBLY__ + #include <linux/string.h> #include <asm/page.h> @@ -64,4 +85,12 @@ static inline void crash_setup_regs(struct pt_regs *newregs, newregs->rip = (unsigned long)current_text_addr(); } } + +NORET_TYPE void +relocate_kernel(unsigned long indirection_page, + unsigned long page_list, + unsigned long start_address) ATTRIB_NORET; + +#endif /* __ASSEMBLY__ */ + #endif /* _X86_64_KEXEC_H */ |