From 57d5f9f808b7650a92f31e9cd3acd3f415a22530 Mon Sep 17 00:00:00 2001 From: Mike Waychison Date: Mon, 14 Mar 2011 23:58:45 -0700 Subject: x86: get_bios_ebda_length() Add a wrapper routine that tells us the length of the EBDA if it is present. This guy also ensures that the returned length doesn't let the EBDA run past the 640KiB mark. Signed-off-by: Mike Waychison Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/bios_ebda.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'arch') diff --git a/arch/x86/include/asm/bios_ebda.h b/arch/x86/include/asm/bios_ebda.h index 3c7521063d3f..5174cf0bf590 100644 --- a/arch/x86/include/asm/bios_ebda.h +++ b/arch/x86/include/asm/bios_ebda.h @@ -14,6 +14,27 @@ static inline unsigned int get_bios_ebda(void) 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 -- cgit v1.2.3 From f548ccd47d608e88d432745091e13f927ced83f7 Mon Sep 17 00:00:00 2001 From: Mike Waychison Date: Mon, 14 Mar 2011 23:58:50 -0700 Subject: x86: Better comments for get_bios_ebda() Make the comments a bit clearer for get_bios_ebda so that it actually tells us what it is returning. Signed-off-by: Mike Waychison Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/bios_ebda.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/x86/include/asm/bios_ebda.h b/arch/x86/include/asm/bios_ebda.h index 5174cf0bf590..aa6a3170ab5a 100644 --- a/arch/x86/include/asm/bios_ebda.h +++ b/arch/x86/include/asm/bios_ebda.h @@ -4,11 +4,14 @@ #include /* - * 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 */ -- cgit v1.2.3 From 82a3242e11d9e63c8195be46c954efaefee35e22 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Thu, 12 May 2011 16:01:02 -0700 Subject: sysfs: remove "last sysfs file:" line from the oops messages On some arches (x86, sh, arm, unicore, powerpc) the oops message would print out the last sysfs file accessed. This was very useful in finding a number of sysfs and driver core bugs in the 2.5 and early 2.6 development days, but it has been a number of years since this file has actually helped in debugging anything that couldn't also be trivially determined from the stack traceback. So it's time to delete the line. This is good as we need all the space we can get for oops messages at times on consoles. Acked-by: Phil Carmody Acked-by: Ingo Molnar Cc: Andrew Morton Cc: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- arch/arm/kernel/traps.c | 1 - arch/powerpc/kernel/traps.c | 1 - arch/sh/kernel/traps_32.c | 1 - arch/unicore32/kernel/traps.c | 1 - arch/x86/kernel/dumpstack.c | 1 - fs/sysfs/file.c | 12 ------------ include/linux/sysfs.h | 5 ----- 7 files changed, 22 deletions(-) (limited to 'arch') diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 3b54ad19d489..d52eec268b47 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -234,7 +234,6 @@ static int __die(const char *str, int err, struct thread_info *thread, struct pt printk(KERN_EMERG "Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n", str, err, ++die_counter); - sysfs_printk_last_file(); /* trap and error numbers are mostly meaningless on ARM */ ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV); diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 5ddb801bc154..d782cd71c07c 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c @@ -143,7 +143,6 @@ int die(const char *str, struct pt_regs *regs, long err) #endif printk("%s\n", ppc_md.name ? ppc_md.name : ""); - sysfs_printk_last_file(); if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV) == NOTIFY_STOP) return 1; diff --git a/arch/sh/kernel/traps_32.c b/arch/sh/kernel/traps_32.c index 3484c2f65aba..b51a17104b5f 100644 --- a/arch/sh/kernel/traps_32.c +++ b/arch/sh/kernel/traps_32.c @@ -87,7 +87,6 @@ void die(const char * str, struct pt_regs * regs, long err) bust_spinlocks(1); printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter); - sysfs_printk_last_file(); print_modules(); show_regs(regs); diff --git a/arch/unicore32/kernel/traps.c b/arch/unicore32/kernel/traps.c index 254e36fa9513..b9a26465e728 100644 --- a/arch/unicore32/kernel/traps.c +++ b/arch/unicore32/kernel/traps.c @@ -192,7 +192,6 @@ static int __die(const char *str, int err, struct thread_info *thread, printk(KERN_EMERG "Internal error: %s: %x [#%d]\n", str, err, ++die_counter); - sysfs_printk_last_file(); /* trap and error numbers are mostly meaningless on UniCore */ ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, \ diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index e2a3f0606da4..f72e7193acc5 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -279,7 +279,6 @@ 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; diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index da3fefe91a8f..1ad8c93c1b85 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -24,13 +24,6 @@ #include "sysfs.h" -/* used in crash dumps to help with debugging */ -static char last_sysfs_file[PATH_MAX]; -void sysfs_printk_last_file(void) -{ - printk(KERN_EMERG "last sysfs file: %s\n", last_sysfs_file); -} - /* * There's one sysfs_buffer for each open file and one * sysfs_open_dirent for each sysfs_dirent with one or more open @@ -337,11 +330,6 @@ static int sysfs_open_file(struct inode *inode, struct file *file) struct sysfs_buffer *buffer; const struct sysfs_ops *ops; int error = -EACCES; - char *p; - - p = d_path(&file->f_path, last_sysfs_file, sizeof(last_sysfs_file)); - if (!IS_ERR(p)) - memmove(last_sysfs_file, p, strlen(p) + 1); /* need attr_sd for attr and ops, its parent for kobj */ if (!sysfs_get_active(attr_sd)) diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 30b881555fa5..c3acda60eee0 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -176,7 +176,6 @@ struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd, const unsigned char *name); struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd); void sysfs_put(struct sysfs_dirent *sd); -void sysfs_printk_last_file(void); /* Called to clear a ns tag when it is no longer valid */ void sysfs_exit_ns(enum kobj_ns_type type, const void *tag); @@ -348,10 +347,6 @@ static inline int __must_check sysfs_init(void) return 0; } -static inline void sysfs_printk_last_file(void) -{ -} - #endif /* CONFIG_SYSFS */ #endif /* _SYSFS_H_ */ -- cgit v1.2.3