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Message-Id: <201312042350.rB4NofnB031607@terminus.zytor.com>
Date: Wed, 4 Dec 2013 15:50:41 -0800
From: "H. Peter Anvin" <hpa@...or.com>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: cxie@...hat.com, dyoung@...hat.com, hjl.tools@...il.com,
hpa@...ux.intel.com, hpa@...or.com, jesse.brandeburg@...el.com,
kevin.b.smith@...el.com, linux-kernel@...r.kernel.org,
matt.fleming@...el.com, mingo@...nel.org, peterz@...radead.org,
seiji.aguchi@....com, tglx@...utronix.de, tony.luck@...el.com
Subject: [GIT PULL] x86 and EFI fixes for v3.13-rc3
Hi Linus,
The following changes since commit 6ce4eac1f600b34f2f7f58f9cd8f0503d79e42ae:
Linux 3.13-rc1 (2013-11-22 11:30:55 -0800)
are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-urgent-for-linus
for you to fetch changes up to e0f6dec35f9286e78879fe1ac92803fd69fc4fdc:
x86, bitops: Correct the assembly constraints to testing bitops (2013-12-04 14:31:28 -0800)
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.
Finally, 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.
----------------------------------------------------------------
H. Peter Anvin (2):
x86-64, build: Always pass in -mno-sse
x86, bitops: Correct the assembly constraints to testing bitops
Madper Xie (1):
efi-pstore: Make efi-pstore return a unique id
Matt Fleming (1):
x86/efi: Fix earlyprintk off-by-one bug
Seiji Aguchi (1):
efivars, efi-pstore: Hold off deletion of sysfs entry until the scan is completed
arch/x86/Makefile | 8 +-
arch/x86/include/asm/atomic.h | 4 +-
arch/x86/include/asm/atomic64_64.h | 4 +-
arch/x86/include/asm/bitops.h | 6 +-
arch/x86/include/asm/local.h | 4 +-
arch/x86/include/asm/rmwcc.h | 8 +-
arch/x86/platform/efi/early_printk.c | 2 +-
drivers/firmware/efi/efi-pstore.c | 163 +++++++++++++++++++++++++++++++----
drivers/firmware/efi/efivars.c | 12 ++-
drivers/firmware/efi/vars.c | 12 ++-
include/linux/efi.h | 4 +
11 files changed, 190 insertions(+), 37 deletions(-)
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 41250fb..eda00f9 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -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)
diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h
index da31c8b..b17f4f4 100644
--- a/arch/x86/include/asm/atomic.h
+++ b/arch/x86/include/asm/atomic.h
@@ -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");
}
/**
diff --git a/arch/x86/include/asm/atomic64_64.h b/arch/x86/include/asm/atomic64_64.h
index 3f065c9..46e9052 100644
--- a/arch/x86/include/asm/atomic64_64.h
+++ b/arch/x86/include/asm/atomic64_64.h
@@ -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");
}
/**
diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h
index 6d76d09..9fc1af7 100644
--- a/arch/x86/include/asm/bitops.h
+++ b/arch/x86/include/asm/bitops.h
@@ -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)
diff --git a/arch/x86/include/asm/local.h b/arch/x86/include/asm/local.h
index 5b23e60..4ad6560 100644
--- a/arch/x86/include/asm/local.h
+++ b/arch/x86/include/asm/local.h
@@ -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");
}
/**
diff --git a/arch/x86/include/asm/rmwcc.h b/arch/x86/include/asm/rmwcc.h
index 1ff990f..8f7866a 100644
--- a/arch/x86/include/asm/rmwcc.h
+++ b/arch/x86/include/asm/rmwcc.h
@@ -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 */
diff --git a/arch/x86/platform/efi/early_printk.c b/arch/x86/platform/efi/early_printk.c
index 6599a00..81b506d 100644
--- a/arch/x86/platform/efi/early_printk.c
+++ b/arch/x86/platform/efi/early_printk.c
@@ -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;
diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index 5002d50..743fd42 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -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;
}
diff --git a/drivers/firmware/efi/efivars.c b/drivers/firmware/efi/efivars.c
index 933eb02..3dc2482 100644
--- a/drivers/firmware/efi/efivars.c
+++ b/drivers/firmware/efi/efivars.c
@@ -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;
diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index 391c67b..b22659c 100644
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -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;
}
diff --git a/include/linux/efi.h b/include/linux/efi.h
index bc5687d..11ce678 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -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 */
--
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