diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/bios_ebda.h | 28 | ||||
| -rw-r--r-- | arch/x86/kernel/dumpstack.c | 1 |
2 files changed, 26 insertions, 3 deletions
diff --git a/arch/x86/include/asm/bios_ebda.h b/arch/x86/include/asm/bios_ebda.h index 3c7521063d3f..aa6a3170ab5a 100644 --- a/arch/x86/include/asm/bios_ebda.h +++ b/arch/x86/include/asm/bios_ebda.h @@ -4,16 +4,40 @@ #include <asm/io.h> /* - * there is a real-mode segmented pointer pointing to the - * 4K EBDA area at 0x40E. + * Returns physical address of EBDA. Returns 0 if there is no EBDA. */ static inline unsigned int get_bios_ebda(void) { + /* + * There is a real-mode segmented pointer pointing to the + * 4K EBDA area at 0x40E. + */ unsigned int address = *(unsigned short *)phys_to_virt(0x40E); address <<= 4; return address; /* 0 means none */ } +/* + * Return the sanitized length of the EBDA in bytes, if it exists. + */ +static inline unsigned int get_bios_ebda_length(void) +{ + unsigned int address; + unsigned int length; + + address = get_bios_ebda(); + if (!address) + return 0; + + /* EBDA length is byte 0 of the EBDA (stored in KiB) */ + length = *(unsigned char *)phys_to_virt(address); + length <<= 10; + + /* Trim the length if it extends beyond 640KiB */ + length = min_t(unsigned int, (640 * 1024) - address, length); + return length; +} + void reserve_ebda_region(void); #ifdef CONFIG_X86_CHECK_BIOS_CORRUPTION diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index f478ff6877ef..1aae78f775fc 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -263,7 +263,6 @@ int __kprobes __die(const char *str, struct pt_regs *regs, long err) printk("DEBUG_PAGEALLOC"); #endif printk("\n"); - sysfs_printk_last_file(); if (notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV) == NOTIFY_STOP) return 1; |