From 57cac4d1880527e0baf6c2fda529d2ad1d815aec Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Sat, 18 Oct 2008 20:28:25 -0700 Subject: [PATCH] kdump: make elfcorehdr_addr independent of CONFIG_PROC_VMCORE o elfcorehdr_addr is used by not only the code under CONFIG_PROC_VMCORE but also by the code which is not inside CONFIG_PROC_VMCORE. For example, is_kdump_kernel() is used by powerpc code to determine if kernel is booting after a panic then use previous kernel's TCE table. So even if CONFIG_PROC_VMCORE is not set in second kernel, one should be able to correctly determine that we are booting after a panic and setup calgary iommu accordingly. o So remove the assumption that elfcorehdr_addr is under CONFIG_PROC_VMCORE. o Move definition of elfcorehdr_addr to arch dependent crash files. (Unfortunately crash dump does not have an arch independent file otherwise that would have been the best place). o kexec.c is not the right place as one can Have CRASH_DUMP enabled in second kernel without KEXEC being enabled. o I don't see sh setup code parsing the command line for elfcorehdr_addr. I am wondering how does vmcore interface work on sh. Anyway, I am atleast defining elfcoredhr_addr so that compilation is not broken on sh. Signed-off-by: Vivek Goyal Acked-by: "Eric W. Biederman" Acked-by: Simon Horman Acked-by: Paul Mundt Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/ia64/kernel/crash_dump.c | 4 ++++ arch/ia64/kernel/setup.c | 9 ++++++++- arch/powerpc/kernel/crash_dump.c | 10 ++++++++-- arch/sh/kernel/crash_dump.c | 3 +++ arch/x86/kernel/crash_dump_32.c | 3 +++ arch/x86/kernel/crash_dump_64.c | 3 +++ arch/x86/kernel/setup.c | 8 +++++++- fs/proc/vmcore.c | 3 --- include/linux/crash_dump.h | 14 ++++++++++---- 9 files changed, 46 insertions(+), 11 deletions(-) diff --git a/arch/ia64/kernel/crash_dump.c b/arch/ia64/kernel/crash_dump.c index da60e90eeeb..23e91290e41 100644 --- a/arch/ia64/kernel/crash_dump.c +++ b/arch/ia64/kernel/crash_dump.c @@ -8,10 +8,14 @@ #include #include +#include #include #include +/* Stores the physical address of elf header of crash image. */ +unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX; + /** * copy_oldmem_page - copy one page from "oldmem" * @pfn: page frame number to be copied diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c index de636b21567..a0286be6c23 100644 --- a/arch/ia64/kernel/setup.c +++ b/arch/ia64/kernel/setup.c @@ -478,7 +478,12 @@ static __init int setup_nomca(char *s) } early_param("nomca", setup_nomca); -#ifdef CONFIG_PROC_VMCORE +/* + * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by + * is_kdump_kernel() to determine if we are booting after a panic. Hence + * ifdef it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE. + */ +#ifdef CONFIG_CRASH_DUMP /* elfcorehdr= specifies the location of elf core header * stored by the crashed kernel. */ @@ -491,7 +496,9 @@ static int __init parse_elfcorehdr(char *arg) return 0; } early_param("elfcorehdr", parse_elfcorehdr); +#endif +#ifdef CONFIG_PROC_VMCORE int __init reserve_elfcorehdr(unsigned long *start, unsigned long *end) { unsigned long length; diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c index a323c9b32ee..97e05637972 100644 --- a/arch/powerpc/kernel/crash_dump.c +++ b/arch/powerpc/kernel/crash_dump.c @@ -27,6 +27,9 @@ #define DBG(fmt...) #endif +/* Stores the physical address of elf header of crash image. */ +unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX; + void __init reserve_kdump_trampoline(void) { lmb_reserve(0, KDUMP_RESERVE_LIMIT); @@ -66,7 +69,11 @@ void __init setup_kdump_trampoline(void) DBG(" <- setup_kdump_trampoline()\n"); } -#ifdef CONFIG_PROC_VMCORE +/* + * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by + * is_kdump_kernel() to determine if we are booting after a panic. Hence + * ifdef it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE. + */ static int __init parse_elfcorehdr(char *p) { if (p) @@ -75,7 +82,6 @@ static int __init parse_elfcorehdr(char *p) return 1; } __setup("elfcorehdr=", parse_elfcorehdr); -#endif static int __init parse_savemaxmem(char *p) { diff --git a/arch/sh/kernel/crash_dump.c b/arch/sh/kernel/crash_dump.c index 4a2ecbe27d8..95d21625556 100644 --- a/arch/sh/kernel/crash_dump.c +++ b/arch/sh/kernel/crash_dump.c @@ -10,6 +10,9 @@ #include #include +/* Stores the physical address of elf header of crash image. */ +unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX; + /** * copy_oldmem_page - copy one page from "oldmem" * @pfn: page frame number to be copied diff --git a/arch/x86/kernel/crash_dump_32.c b/arch/x86/kernel/crash_dump_32.c index 72d0c56c1b4..f7cdb3b457a 100644 --- a/arch/x86/kernel/crash_dump_32.c +++ b/arch/x86/kernel/crash_dump_32.c @@ -13,6 +13,9 @@ static void *kdump_buf_page; +/* Stores the physical address of elf header of crash image. */ +unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX; + /** * copy_oldmem_page - copy one page from "oldmem" * @pfn: page frame number to be copied diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c index e90a60ef10c..045b36cada6 100644 --- a/arch/x86/kernel/crash_dump_64.c +++ b/arch/x86/kernel/crash_dump_64.c @@ -10,6 +10,9 @@ #include #include +/* Stores the physical address of elf header of crash image. */ +unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX; + /** * copy_oldmem_page - copy one page from "oldmem" * @pfn: page frame number to be copied diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 2255782e8d4..b2c97874ec0 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -561,7 +561,13 @@ static void __init reserve_standard_io_resources(void) } -#ifdef CONFIG_PROC_VMCORE +/* + * Note: elfcorehdr_addr is not just limited to vmcore. It is also used by + * is_kdump_kernel() to determine if we are booting after a panic. Hence + * ifdef it under CONFIG_CRASH_DUMP and not CONFIG_PROC_VMCORE. + */ + +#ifdef CONFIG_CRASH_DUMP /* elfcorehdr= specifies the location of elf core header * stored by the crashed kernel. This option will be passed * by kexec loader to the capture kernel. diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 841368b87a2..4c65ca432d3 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -32,9 +32,6 @@ static size_t elfcorebuf_sz; /* Total size of vmcore file. */ static u64 vmcore_size; -/* Stores the physical address of elf header of crash image. */ -unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX; - struct proc_dir_entry *proc_vmcore = NULL; /* Reads a page from the oldmem device from given offset. */ diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h index 025e4f57510..de027d1db74 100644 --- a/include/linux/crash_dump.h +++ b/include/linux/crash_dump.h @@ -9,11 +9,7 @@ #define ELFCORE_ADDR_MAX (-1ULL) -#ifdef CONFIG_PROC_VMCORE extern unsigned long long elfcorehdr_addr; -#else -static const unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX; -#endif extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, unsigned long, int); @@ -28,6 +24,16 @@ extern struct proc_dir_entry *proc_vmcore; #define vmcore_elf_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x)) +/* + * is_kdump_kernel() checks whether this kernel is booting after a panic of + * previous kernel or not. This is determined by checking if previous kernel + * has passed the elf core header address on command line. + * + * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will + * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of + * previous kernel. + */ + static inline int is_kdump_kernel(void) { return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0; -- 2.41.1