diff options
| -rw-r--r-- | arch/ia64/kernel/setup.c | 4 | ||||
| -rw-r--r-- | fs/proc/vmcore.c | 2 | ||||
| -rw-r--r-- | include/linux/crash_dump.h | 24 |
3 files changed, 27 insertions, 3 deletions
diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c index a0286be6c235..60286522d54a 100644 --- a/arch/ia64/kernel/setup.c +++ b/arch/ia64/kernel/setup.c @@ -509,11 +509,11 @@ int __init reserve_elfcorehdr(unsigned long *start, unsigned long *end) * to work properly. */ - if (elfcorehdr_addr >= ELFCORE_ADDR_MAX) + if (!is_vmcore_usable()) return -EINVAL; if ((length = vmcore_find_descriptor_size(elfcorehdr_addr)) == 0) { - elfcorehdr_addr = ELFCORE_ADDR_MAX; + vmcore_unusable(); return -EINVAL; } diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 4c65ca432d30..cd9ca67f841b 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -644,7 +644,7 @@ static int __init vmcore_init(void) int rc = 0; /* If elfcorehdr= has been passed in cmdline, then capture the dump.*/ - if (!(elfcorehdr_addr < ELFCORE_ADDR_MAX)) + if (!(is_vmcore_usable())) return rc; rc = parse_crash_elf_headers(); if (rc) { diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h index de027d1db745..0acf3b737e2e 100644 --- a/include/linux/crash_dump.h +++ b/include/linux/crash_dump.h @@ -8,6 +8,7 @@ #include <linux/proc_fs.h> #define ELFCORE_ADDR_MAX (-1ULL) +#define ELFCORE_ADDR_ERR (-2ULL) extern unsigned long long elfcorehdr_addr; @@ -38,6 +39,29 @@ static inline int is_kdump_kernel(void) { return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0; } + +/* is_vmcore_usable() checks if the kernel is booting after a panic and + * the vmcore region is usable. + * + * This makes use of the fact that due to alignment -2ULL is not + * a valid pointer, much in the vain of IS_ERR(), except + * dealing directly with an unsigned long long rather than a pointer. + */ + +static inline int is_vmcore_usable(void) +{ + return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; +} + +/* vmcore_unusable() marks the vmcore as unusable, + * without disturbing the logic of is_kdump_kernel() + */ + +static inline void vmcore_unusable(void) +{ + if (is_kdump_kernel()) + elfcorehdr_addr = ELFCORE_ADDR_ERR; +} #else /* !CONFIG_CRASH_DUMP */ static inline int is_kdump_kernel(void) { return 0; } #endif /* CONFIG_CRASH_DUMP */ |