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Merge branch 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 and EFI fixes from Peter Anvin:
 "Half of these are EFI-related:

  The by far biggest change is the change to hold off the deletion of a
  sysfs entry while a backend scan is in progress.  This is to avoid
  calling kmemdup() while under a spinlock.

  The other major change is for each entry in the EFI pstore backend to
  get a unique identifier, as required by the pstore filesystem proper.

  The other changes are:

  A fix to the recent consolidation and optimization of using "asm goto"
  with read-modify-write operation, which broke the bitops; specifically
  in such a way that we could end up generating invalid code.

  A build hack to make sure we compile with -mno-sse.  icc, and most
  likely future versions of gcc, can generate SSE instructions unless we
  tell it not to.

  A comment-only patch to a change the was due in part to an unpublished
  erratum; now when the erratum is published we want to add a comment
  explaining why"

* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic, doc: Justification for disabling IO APIC before Local APIC
  x86, bitops: Correct the assembly constraints to testing bitops
  x86-64, build: Always pass in -mno-sse
  efi-pstore: Make efi-pstore return a unique id
  x86/efi: Fix earlyprintk off-by-one bug
  efivars, efi-pstore: Hold off deletion of sysfs entry until the scan is completed
This commit is contained in:
Linus Torvalds 2013-12-04 21:45:21 -08:00
parent 8ecffd7914 2885432aaf
commit 53c6de5026
12 changed files with 201 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
arch/x86/Makefile
View File

@ -31,6 +31,9 @@ ifeq ($(CONFIG_X86_32),y)
KBUILD_CFLAGS += -msoft-float -mregparm=3 -freg-struct-return
# Don't autogenerate SSE instructions
KBUILD_CFLAGS += -mno-sse
# Never want PIC in a 32-bit kernel, prevent breakage with GCC built
# with nonstandard options
KBUILD_CFLAGS += -fno-pic
@ -57,8 +60,11 @@ else
KBUILD_AFLAGS += -m64
KBUILD_CFLAGS += -m64
# Don't autogenerate SSE instructions
KBUILD_CFLAGS += -mno-sse
# Use -mpreferred-stack-boundary=3 if supported.
KBUILD_CFLAGS += $(call cc-option,-mno-sse -mpreferred-stack-boundary=3)
KBUILD_CFLAGS += $(call cc-option,-mpreferred-stack-boundary=3)
# FIXME - should be integrated in Makefile.cpu (Makefile_32.cpu)
cflags-$(CONFIG_MK8) += $(call cc-option,-march=k8)

4
arch/x86/include/asm/atomic.h
View File

@ -77,7 +77,7 @@ static inline void atomic_sub(int i, atomic_t *v)
*/
static inline int atomic_sub_and_test(int i, atomic_t *v)
{
GEN_BINARY_RMWcc(LOCK_PREFIX "subl", v->counter, i, "%0", "e");
GEN_BINARY_RMWcc(LOCK_PREFIX "subl", v->counter, "er", i, "%0", "e");
}
/**
@ -141,7 +141,7 @@ static inline int atomic_inc_and_test(atomic_t *v)
*/
static inline int atomic_add_negative(int i, atomic_t *v)
{
GEN_BINARY_RMWcc(LOCK_PREFIX "addl", v->counter, i, "%0", "s");
GEN_BINARY_RMWcc(LOCK_PREFIX "addl", v->counter, "er", i, "%0", "s");
}
/**

4
arch/x86/include/asm/atomic64_64.h
View File

@ -72,7 +72,7 @@ static inline void atomic64_sub(long i, atomic64_t *v)
*/
static inline int atomic64_sub_and_test(long i, atomic64_t *v)
{
GEN_BINARY_RMWcc(LOCK_PREFIX "subq", v->counter, i, "%0", "e");
GEN_BINARY_RMWcc(LOCK_PREFIX "subq", v->counter, "er", i, "%0", "e");
}
/**
@ -138,7 +138,7 @@ static inline int atomic64_inc_and_test(atomic64_t *v)
*/
static inline int atomic64_add_negative(long i, atomic64_t *v)
{
GEN_BINARY_RMWcc(LOCK_PREFIX "addq", v->counter, i, "%0", "s");
GEN_BINARY_RMWcc(LOCK_PREFIX "addq", v->counter, "er", i, "%0", "s");
}
/**

6
arch/x86/include/asm/bitops.h
View File

@ -205,7 +205,7 @@ static inline void change_bit(long nr, volatile unsigned long *addr)
*/
static inline int test_and_set_bit(long nr, volatile unsigned long *addr)
{
GEN_BINARY_RMWcc(LOCK_PREFIX "bts", *addr, nr, "%0", "c");
GEN_BINARY_RMWcc(LOCK_PREFIX "bts", *addr, "Ir", nr, "%0", "c");
}
/**
@ -251,7 +251,7 @@ static inline int __test_and_set_bit(long nr, volatile unsigned long *addr)
*/
static inline int test_and_clear_bit(long nr, volatile unsigned long *addr)
{
GEN_BINARY_RMWcc(LOCK_PREFIX "btr", *addr, nr, "%0", "c");
GEN_BINARY_RMWcc(LOCK_PREFIX "btr", *addr, "Ir", nr, "%0", "c");
}
/**
@ -304,7 +304,7 @@ static inline int __test_and_change_bit(long nr, volatile unsigned long *addr)
*/
static inline int test_and_change_bit(long nr, volatile unsigned long *addr)
{
GEN_BINARY_RMWcc(LOCK_PREFIX "btc", *addr, nr, "%0", "c");
GEN_BINARY_RMWcc(LOCK_PREFIX "btc", *addr, "Ir", nr, "%0", "c");
}
static __always_inline int constant_test_bit(long nr, const volatile unsigned long *addr)

4
arch/x86/include/asm/local.h
View File

@ -52,7 +52,7 @@ static inline void local_sub(long i, local_t *l)
*/
static inline int local_sub_and_test(long i, local_t *l)
{
GEN_BINARY_RMWcc(_ASM_SUB, l->a.counter, i, "%0", "e");
GEN_BINARY_RMWcc(_ASM_SUB, l->a.counter, "er", i, "%0", "e");
}
/**
@ -92,7 +92,7 @@ static inline int local_inc_and_test(local_t *l)
*/
static inline int local_add_negative(long i, local_t *l)
{
GEN_BINARY_RMWcc(_ASM_ADD, l->a.counter, i, "%0", "s");
GEN_BINARY_RMWcc(_ASM_ADD, l->a.counter, "er", i, "%0", "s");
}
/**

8
arch/x86/include/asm/rmwcc.h
View File

@ -16,8 +16,8 @@ cc_label: \
#define GEN_UNARY_RMWcc(op, var, arg0, cc) \
__GEN_RMWcc(op " " arg0, var, cc)
#define GEN_BINARY_RMWcc(op, var, val, arg0, cc) \
__GEN_RMWcc(op " %1, " arg0, var, cc, "er" (val))
#define GEN_BINARY_RMWcc(op, var, vcon, val, arg0, cc) \
__GEN_RMWcc(op " %1, " arg0, var, cc, vcon (val))
#else /* !CC_HAVE_ASM_GOTO */
@ -33,8 +33,8 @@ do { \
#define GEN_UNARY_RMWcc(op, var, arg0, cc) \
__GEN_RMWcc(op " " arg0, var, cc)
#define GEN_BINARY_RMWcc(op, var, val, arg0, cc) \
__GEN_RMWcc(op " %2, " arg0, var, cc, "er" (val))
#define GEN_BINARY_RMWcc(op, var, vcon, val, arg0, cc) \
__GEN_RMWcc(op " %2, " arg0, var, cc, vcon (val))
#endif /* CC_HAVE_ASM_GOTO */

11
arch/x86/kernel/reboot.c
View File

@ -558,6 +558,17 @@ void native_machine_shutdown(void)
{
/* Stop the cpus and apics */
#ifdef CONFIG_X86_IO_APIC
/*
* Disabling IO APIC before local APIC is a workaround for
* erratum AVR31 in "Intel Atom Processor C2000 Product Family
* Specification Update". In this situation, interrupts that target
* a Logical Processor whose Local APIC is either in the process of
* being hardware disabled or software disabled are neither delivered
* nor discarded. When this erratum occurs, the processor may hang.
*
* Even without the erratum, it still makes sense to quiet IO APIC
* before disabling Local APIC.
*/
disable_IO_APIC();
#endif

2
arch/x86/platform/efi/early_printk.c
View File

@ -142,7 +142,7 @@ early_efi_write(struct console *con, const char *str, unsigned int num)
efi_y += font->height;
}
if (efi_y + font->height >= si->lfb_height) {
if (efi_y + font->height > si->lfb_height) {
u32 i;
efi_y -= font->height;

163
drivers/firmware/efi/efi-pstore.c
View File

@ -18,14 +18,12 @@ module_param_named(pstore_disable, efivars_pstore_disable, bool, 0644);
static int efi_pstore_open(struct pstore_info *psi)
{
efivar_entry_iter_begin();
psi->data = NULL;
return 0;
}
static int efi_pstore_close(struct pstore_info *psi)
{
efivar_entry_iter_end();
psi->data = NULL;
return 0;
}
@ -39,6 +37,12 @@ struct pstore_read_data {
char **buf;
};
static inline u64 generic_id(unsigned long timestamp,
unsigned int part, int count)
{
return (timestamp * 100 + part) * 1000 + count;
}
static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
{
efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
@ -57,7 +61,7 @@ static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
if (sscanf(name, "dump-type%u-%u-%d-%lu-%c",
cb_data->type, &part, &cnt, &time, &data_type) == 5) {
*cb_data->id = part;
*cb_data->id = generic_id(time, part, cnt);
*cb_data->count = cnt;
cb_data->timespec->tv_sec = time;
cb_data->timespec->tv_nsec = 0;
@ -67,7 +71,7 @@ static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
*cb_data->compressed = false;
} else if (sscanf(name, "dump-type%u-%u-%d-%lu",
cb_data->type, &part, &cnt, &time) == 4) {
*cb_data->id = part;
*cb_data->id = generic_id(time, part, cnt);
*cb_data->count = cnt;
cb_data->timespec->tv_sec = time;
cb_data->timespec->tv_nsec = 0;
@ -79,7 +83,7 @@ static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
* which doesn't support holding
* multiple logs, remains.
*/
*cb_data->id = part;
*cb_data->id = generic_id(time, part, 0);
*cb_data->count = 0;
cb_data->timespec->tv_sec = time;
cb_data->timespec->tv_nsec = 0;
@ -91,19 +95,125 @@ static int efi_pstore_read_func(struct efivar_entry *entry, void *data)
__efivar_entry_get(entry, &entry->var.Attributes,
&entry->var.DataSize, entry->var.Data);
size = entry->var.DataSize;
memcpy(*cb_data->buf, entry->var.Data,
(size_t)min_t(unsigned long, EFIVARS_DATA_SIZE_MAX, size));
*cb_data->buf = kmemdup(entry->var.Data, size, GFP_KERNEL);
if (*cb_data->buf == NULL)
return -ENOMEM;
return size;
}
/**
* efi_pstore_scan_sysfs_enter
* @entry: scanning entry
* @next: next entry
* @head: list head
*/
static void efi_pstore_scan_sysfs_enter(struct efivar_entry *pos,
struct efivar_entry *next,
struct list_head *head)
{
pos->scanning = true;
if (&next->list != head)
next->scanning = true;
}
/**
* __efi_pstore_scan_sysfs_exit
* @entry: deleting entry
* @turn_off_scanning: Check if a scanning flag should be turned off
*/
static inline void __efi_pstore_scan_sysfs_exit(struct efivar_entry *entry,
bool turn_off_scanning)
{
if (entry->deleting) {
list_del(&entry->list);
efivar_entry_iter_end();
efivar_unregister(entry);
efivar_entry_iter_begin();
} else if (turn_off_scanning)
entry->scanning = false;
}
/**
* efi_pstore_scan_sysfs_exit
* @pos: scanning entry
* @next: next entry
* @head: list head
* @stop: a flag checking if scanning will stop
*/
static void efi_pstore_scan_sysfs_exit(struct efivar_entry *pos,
struct efivar_entry *next,
struct list_head *head, bool stop)
{
__efi_pstore_scan_sysfs_exit(pos, true);
if (stop)
__efi_pstore_scan_sysfs_exit(next, &next->list != head);
}
/**
* efi_pstore_sysfs_entry_iter
*
* @data: function-specific data to pass to callback
* @pos: entry to begin iterating from
*
* You MUST call efivar_enter_iter_begin() before this function, and
* efivar_entry_iter_end() afterwards.
*
* It is possible to begin iteration from an arbitrary entry within
* the list by passing @pos. @pos is updated on return to point to
* the next entry of the last one passed to efi_pstore_read_func().
* To begin iterating from the beginning of the list @pos must be %NULL.
*/
static int efi_pstore_sysfs_entry_iter(void *data, struct efivar_entry **pos)
{
struct efivar_entry *entry, *n;
struct list_head *head = &efivar_sysfs_list;
int size = 0;
if (!*pos) {
list_for_each_entry_safe(entry, n, head, list) {
efi_pstore_scan_sysfs_enter(entry, n, head);
size = efi_pstore_read_func(entry, data);
efi_pstore_scan_sysfs_exit(entry, n, head, size < 0);
if (size)
break;
}
*pos = n;
return size;
}
list_for_each_entry_safe_from((*pos), n, head, list) {
efi_pstore_scan_sysfs_enter((*pos), n, head);
size = efi_pstore_read_func((*pos), data);
efi_pstore_scan_sysfs_exit((*pos), n, head, size < 0);
if (size)
break;
}
*pos = n;
return size;
}
/**
* efi_pstore_read
*
* This function returns a size of NVRAM entry logged via efi_pstore_write().
* The meaning and behavior of efi_pstore/pstore are as below.
*
* size > 0: Got data of an entry logged via efi_pstore_write() successfully,
* and pstore filesystem will continue reading subsequent entries.
* size == 0: Entry was not logged via efi_pstore_write(),
* and efi_pstore driver will continue reading subsequent entries.
* size < 0: Failed to get data of entry logging via efi_pstore_write(),
* and pstore will stop reading entry.
*/
static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
int *count, struct timespec *timespec,
char **buf, bool *compressed,
struct pstore_info *psi)
{
struct pstore_read_data data;
ssize_t size;
data.id = id;
data.type = type;
@ -112,8 +222,17 @@ static ssize_t efi_pstore_read(u64 *id, enum pstore_type_id *type,
data.compressed = compressed;
data.buf = buf;
return __efivar_entry_iter(efi_pstore_read_func, &efivar_sysfs_list, &data,
(struct efivar_entry **)&psi->data);
*data.buf = kzalloc(EFIVARS_DATA_SIZE_MAX, GFP_KERNEL);
if (!*data.buf)
return -ENOMEM;
efivar_entry_iter_begin();
size = efi_pstore_sysfs_entry_iter(&data,
(struct efivar_entry **)&psi->data);
efivar_entry_iter_end();
if (size <= 0)
kfree(*data.buf);
return size;
}
static int efi_pstore_write(enum pstore_type_id type,
@ -184,9 +303,17 @@ static int efi_pstore_erase_func(struct efivar_entry *entry, void *data)
return 0;
}
if (entry->scanning) {
/*
* Skip deletion because this entry will be deleted
* after scanning is completed.
*/
entry->deleting = true;
} else
list_del(&entry->list);
/* found */
__efivar_entry_delete(entry);
list_del(&entry->list);
return 1;
}
@ -199,14 +326,16 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
char name[DUMP_NAME_LEN];
efi_char16_t efi_name[DUMP_NAME_LEN];
int found, i;
unsigned int part;
sprintf(name, "dump-type%u-%u-%d-%lu", type, (unsigned int)id, count,
time.tv_sec);
do_div(id, 1000);
part = do_div(id, 100);
sprintf(name, "dump-type%u-%u-%d-%lu", type, part, count, time.tv_sec);
for (i = 0; i < DUMP_NAME_LEN; i++)
efi_name[i] = name[i];
edata.id = id;
edata.id = part;
edata.type = type;
edata.count = count;
edata.time = time;
@ -214,10 +343,12 @@ static int efi_pstore_erase(enum pstore_type_id type, u64 id, int count,
efivar_entry_iter_begin();
found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list, &edata, &entry);
efivar_entry_iter_end();
if (found)
if (found && !entry->scanning) {
efivar_entry_iter_end();
efivar_unregister(entry);
} else
efivar_entry_iter_end();
return 0;
}

12
drivers/firmware/efi/efivars.c
View File

@ -383,12 +383,16 @@ static ssize_t efivar_delete(struct file *filp, struct kobject *kobj,
else if (__efivar_entry_delete(entry))
err = -EIO;
efivar_entry_iter_end();
if (err)
if (err) {
efivar_entry_iter_end();
return err;
}
efivar_unregister(entry);
if (!entry->scanning) {
efivar_entry_iter_end();
efivar_unregister(entry);
} else
efivar_entry_iter_end();
/* It's dead Jim.... */
return count;

12
drivers/firmware/efi/vars.c
View File

@ -683,8 +683,16 @@ struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
if (!found)
return NULL;
if (remove)
list_del(&entry->list);
if (remove) {
if (entry->scanning) {
/*
* The entry will be deleted
* after scanning is completed.
*/
entry->deleting = true;
} else
list_del(&entry->list);
}
return entry;
}

4
include/linux/efi.h
View File

@ -801,6 +801,8 @@ struct efivar_entry {
struct efi_variable var;
struct list_head list;
struct kobject kobj;
bool scanning;
bool deleting;
};
@ -866,6 +868,8 @@ void efivar_run_worker(void);
#if defined(CONFIG_EFI_VARS) || defined(CONFIG_EFI_VARS_MODULE)
int efivars_sysfs_init(void);
#define EFIVARS_DATA_SIZE_MAX 1024
#endif /* CONFIG_EFI_VARS */
#endif /* _LINUX_EFI_H */