From: Matt Fleming <matt@codeblueprint.co.uk>
To: Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
"H . Peter Anvin" <hpa@zytor.com>
Cc: Sylvain Chouleur <sylvain.chouleur@intel.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org,
Matt Fleming <matt@codeblueprint.co.uk>,
Leif Lindholm <leif.lindholm@linaro.org>,
Mark Rutland <mark.rutland@arm.com>,
Sylvain Chouleur <sylvain.chouleur@gmail.com>
Subject: [PATCH 14/29] efi: Use a file local lock for efivars
Date: Fri, 9 Sep 2016 16:18:36 +0100 [thread overview]
Message-ID: <20160909151851.27577-15-matt@codeblueprint.co.uk> (raw)
In-Reply-To: <20160909151851.27577-1-matt@codeblueprint.co.uk>
From: Sylvain Chouleur <sylvain.chouleur@intel.com>
This patch replaces the spinlock in the efivars struct with a single lock
for the whole vars.c file. The goal of this lock is to protect concurrent
calls to efi variable services, registering and unregistering. This allows
us to register new efivars operations without having in-progress call.
Signed-off-by: Sylvain Chouleur <sylvain.chouleur@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Sylvain Chouleur <sylvain.chouleur@gmail.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
---
drivers/firmware/efi/vars.c | 83 +++++++++++++++++++++++++--------------------
include/linux/efi.h | 6 ----
2 files changed, 47 insertions(+), 42 deletions(-)
diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c
index d3b751383286..d0d807e1287e 100644
--- a/drivers/firmware/efi/vars.c
+++ b/drivers/firmware/efi/vars.c
@@ -37,6 +37,14 @@
/* Private pointer to registered efivars */
static struct efivars *__efivars;
+/*
+ * efivars_lock protects three things:
+ * 1) efivarfs_list and efivars_sysfs_list
+ * 2) ->ops calls
+ * 3) (un)registration of __efivars
+ */
+static DEFINE_SPINLOCK(efivars_lock);
+
static bool efivar_wq_enabled = true;
DECLARE_WORK(efivar_work, NULL);
EXPORT_SYMBOL_GPL(efivar_work);
@@ -434,7 +442,7 @@ int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
return -ENOMEM;
}
- spin_lock_irq(&__efivars->lock);
+ spin_lock_irq(&efivars_lock);
/*
* Per EFI spec, the maximum storage allocated for both
@@ -450,7 +458,7 @@ int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
switch (status) {
case EFI_SUCCESS:
if (duplicates)
- spin_unlock_irq(&__efivars->lock);
+ spin_unlock_irq(&efivars_lock);
variable_name_size = var_name_strnsize(variable_name,
variable_name_size);
@@ -477,7 +485,7 @@ int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
}
if (duplicates)
- spin_lock_irq(&__efivars->lock);
+ spin_lock_irq(&efivars_lock);
break;
case EFI_NOT_FOUND:
@@ -491,7 +499,7 @@ int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *),
} while (status != EFI_NOT_FOUND);
- spin_unlock_irq(&__efivars->lock);
+ spin_unlock_irq(&efivars_lock);
kfree(variable_name);
@@ -506,9 +514,9 @@ EXPORT_SYMBOL_GPL(efivar_init);
*/
void efivar_entry_add(struct efivar_entry *entry, struct list_head *head)
{
- spin_lock_irq(&__efivars->lock);
+ spin_lock_irq(&efivars_lock);
list_add(&entry->list, head);
- spin_unlock_irq(&__efivars->lock);
+ spin_unlock_irq(&efivars_lock);
}
EXPORT_SYMBOL_GPL(efivar_entry_add);
@@ -518,9 +526,9 @@ EXPORT_SYMBOL_GPL(efivar_entry_add);
*/
void efivar_entry_remove(struct efivar_entry *entry)
{
- spin_lock_irq(&__efivars->lock);
+ spin_lock_irq(&efivars_lock);
list_del(&entry->list);
- spin_unlock_irq(&__efivars->lock);
+ spin_unlock_irq(&efivars_lock);
}
EXPORT_SYMBOL_GPL(efivar_entry_remove);
@@ -537,10 +545,10 @@ EXPORT_SYMBOL_GPL(efivar_entry_remove);
*/
static void efivar_entry_list_del_unlock(struct efivar_entry *entry)
{
- lockdep_assert_held(&__efivars->lock);
+ lockdep_assert_held(&efivars_lock);
list_del(&entry->list);
- spin_unlock_irq(&__efivars->lock);
+ spin_unlock_irq(&efivars_lock);
}
/**
@@ -563,7 +571,7 @@ int __efivar_entry_delete(struct efivar_entry *entry)
const struct efivar_operations *ops = __efivars->ops;
efi_status_t status;
- lockdep_assert_held(&__efivars->lock);
+ lockdep_assert_held(&efivars_lock);
status = ops->set_variable(entry->var.VariableName,
&entry->var.VendorGuid,
@@ -589,12 +597,12 @@ int efivar_entry_delete(struct efivar_entry *entry)
const struct efivar_operations *ops = __efivars->ops;
efi_status_t status;
- spin_lock_irq(&__efivars->lock);
+ spin_lock_irq(&efivars_lock);
status = ops->set_variable(entry->var.VariableName,
&entry->var.VendorGuid,
0, 0, NULL);
if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) {
- spin_unlock_irq(&__efivars->lock);
+ spin_unlock_irq(&efivars_lock);
return efi_status_to_err(status);
}
@@ -632,10 +640,10 @@ int efivar_entry_set(struct efivar_entry *entry, u32 attributes,
efi_char16_t *name = entry->var.VariableName;
efi_guid_t vendor = entry->var.VendorGuid;
- spin_lock_irq(&__efivars->lock);
+ spin_lock_irq(&efivars_lock);
if (head && efivar_entry_find(name, vendor, head, false)) {
- spin_unlock_irq(&__efivars->lock);
+ spin_unlock_irq(&efivars_lock);
return -EEXIST;
}
@@ -644,7 +652,7 @@ int efivar_entry_set(struct efivar_entry *entry, u32 attributes,
status = ops->set_variable(name, &vendor,
attributes, size, data);
- spin_unlock_irq(&__efivars->lock);
+ spin_unlock_irq(&efivars_lock);
return efi_status_to_err(status);
@@ -658,7 +666,7 @@ EXPORT_SYMBOL_GPL(efivar_entry_set);
* from crash/panic handlers.
*
* Crucially, this function will not block if it cannot acquire
- * __efivars->lock. Instead, it returns -EBUSY.
+ * efivars_lock. Instead, it returns -EBUSY.
*/
static int
efivar_entry_set_nonblocking(efi_char16_t *name, efi_guid_t vendor,
@@ -668,20 +676,20 @@ efivar_entry_set_nonblocking(efi_char16_t *name, efi_guid_t vendor,
unsigned long flags;
efi_status_t status;
- if (!spin_trylock_irqsave(&__efivars->lock, flags))
+ if (!spin_trylock_irqsave(&efivars_lock, flags))
return -EBUSY;
status = check_var_size_nonblocking(attributes,
size + ucs2_strsize(name, 1024));
if (status != EFI_SUCCESS) {
- spin_unlock_irqrestore(&__efivars->lock, flags);
+ spin_unlock_irqrestore(&efivars_lock, flags);
return -ENOSPC;
}
status = ops->set_variable_nonblocking(name, &vendor, attributes,
size, data);
- spin_unlock_irqrestore(&__efivars->lock, flags);
+ spin_unlock_irqrestore(&efivars_lock, flags);
return efi_status_to_err(status);
}
@@ -727,21 +735,21 @@ int efivar_entry_set_safe(efi_char16_t *name, efi_guid_t vendor, u32 attributes,
size, data);
if (!block) {
- if (!spin_trylock_irqsave(&__efivars->lock, flags))
+ if (!spin_trylock_irqsave(&efivars_lock, flags))
return -EBUSY;
} else {
- spin_lock_irqsave(&__efivars->lock, flags);
+ spin_lock_irqsave(&efivars_lock, flags);
}
status = check_var_size(attributes, size + ucs2_strsize(name, 1024));
if (status != EFI_SUCCESS) {
- spin_unlock_irqrestore(&__efivars->lock, flags);
+ spin_unlock_irqrestore(&efivars_lock, flags);
return -ENOSPC;
}
status = ops->set_variable(name, &vendor, attributes, size, data);
- spin_unlock_irqrestore(&__efivars->lock, flags);
+ spin_unlock_irqrestore(&efivars_lock, flags);
return efi_status_to_err(status);
}
@@ -771,7 +779,7 @@ struct efivar_entry *efivar_entry_find(efi_char16_t *name, efi_guid_t guid,
int strsize1, strsize2;
bool found = false;
- lockdep_assert_held(&__efivars->lock);
+ lockdep_assert_held(&efivars_lock);
list_for_each_entry_safe(entry, n, head, list) {
strsize1 = ucs2_strsize(name, 1024);
@@ -814,10 +822,10 @@ int efivar_entry_size(struct efivar_entry *entry, unsigned long *size)
*size = 0;
- spin_lock_irq(&__efivars->lock);
+ spin_lock_irq(&efivars_lock);
status = ops->get_variable(entry->var.VariableName,
&entry->var.VendorGuid, NULL, size, NULL);
- spin_unlock_irq(&__efivars->lock);
+ spin_unlock_irq(&efivars_lock);
if (status != EFI_BUFFER_TOO_SMALL)
return efi_status_to_err(status);
@@ -843,7 +851,7 @@ int __efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
const struct efivar_operations *ops = __efivars->ops;
efi_status_t status;
- lockdep_assert_held(&__efivars->lock);
+ lockdep_assert_held(&efivars_lock);
status = ops->get_variable(entry->var.VariableName,
&entry->var.VendorGuid,
@@ -866,11 +874,11 @@ int efivar_entry_get(struct efivar_entry *entry, u32 *attributes,
const struct efivar_operations *ops = __efivars->ops;
efi_status_t status;
- spin_lock_irq(&__efivars->lock);
+ spin_lock_irq(&efivars_lock);
status = ops->get_variable(entry->var.VariableName,
&entry->var.VendorGuid,
attributes, size, data);
- spin_unlock_irq(&__efivars->lock);
+ spin_unlock_irq(&efivars_lock);
return efi_status_to_err(status);
}
@@ -917,7 +925,7 @@ int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
* set_variable call, and removal of the variable from the efivars
* list (in the case of an authenticated delete).
*/
- spin_lock_irq(&__efivars->lock);
+ spin_lock_irq(&efivars_lock);
/*
* Ensure that the available space hasn't shrunk below the safe level
@@ -957,7 +965,7 @@ int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
if (status == EFI_NOT_FOUND)
efivar_entry_list_del_unlock(entry);
else
- spin_unlock_irq(&__efivars->lock);
+ spin_unlock_irq(&efivars_lock);
if (status && status != EFI_BUFFER_TOO_SMALL)
return efi_status_to_err(status);
@@ -965,7 +973,7 @@ int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes,
return 0;
out:
- spin_unlock_irq(&__efivars->lock);
+ spin_unlock_irq(&efivars_lock);
return err;
}
@@ -980,7 +988,7 @@ EXPORT_SYMBOL_GPL(efivar_entry_set_get_size);
*/
void efivar_entry_iter_begin(void)
{
- spin_lock_irq(&__efivars->lock);
+ spin_lock_irq(&efivars_lock);
}
EXPORT_SYMBOL_GPL(efivar_entry_iter_begin);
@@ -991,7 +999,7 @@ EXPORT_SYMBOL_GPL(efivar_entry_iter_begin);
*/
void efivar_entry_iter_end(void)
{
- spin_unlock_irq(&__efivars->lock);
+ spin_unlock_irq(&efivars_lock);
}
EXPORT_SYMBOL_GPL(efivar_entry_iter_end);
@@ -1112,11 +1120,12 @@ int efivars_register(struct efivars *efivars,
const struct efivar_operations *ops,
struct kobject *kobject)
{
- spin_lock_init(&efivars->lock);
+ spin_lock_irq(&efivars_lock);
efivars->ops = ops;
efivars->kobject = kobject;
__efivars = efivars;
+ spin_unlock_irq(&efivars_lock);
return 0;
}
@@ -1133,6 +1142,7 @@ int efivars_unregister(struct efivars *efivars)
{
int rv;
+ spin_lock_irq(&efivars_lock);
if (!__efivars) {
printk(KERN_ERR "efivars not registered\n");
rv = -EINVAL;
@@ -1148,6 +1158,7 @@ int efivars_unregister(struct efivars *efivars)
rv = 0;
out:
+ spin_unlock_irq(&efivars_lock);
return rv;
}
EXPORT_SYMBOL_GPL(efivars_unregister);
diff --git a/include/linux/efi.h b/include/linux/efi.h
index d8b555db81c7..deecb2902715 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1157,12 +1157,6 @@ struct efivar_operations {
};
struct efivars {
- /*
- * ->lock protects two things:
- * 1) efivarfs_list and efivars_sysfs_list
- * 2) ->ops calls
- */
- spinlock_t lock;
struct kset *kset;
struct kobject *kobject;
const struct efivar_operations *ops;
--
2.9.3
next prev parent reply other threads:[~2016-09-09 15:18 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-09 15:18 [GIT PULL 00/29] EFI changes for v4.9 Matt Fleming
2016-09-09 15:18 ` [PATCH 01/29] x86/efi: Test for EFI_MEMMAP functionality when iterating EFI memmap Matt Fleming
2016-09-09 15:18 ` [PATCH 03/29] efi: Refactor efi_memmap_init_early() into arch-neutral code Matt Fleming
2016-09-09 15:18 ` [PATCH 05/29] efi/fake_mem: Refactor main two code chunks into functions Matt Fleming
2016-09-09 15:18 ` [PATCH 06/29] efi: Split out EFI memory map functions into new file Matt Fleming
2016-09-09 15:18 ` [PATCH 08/29] efi: Allow drivers to reserve boot services forever Matt Fleming
2017-01-04 2:48 ` Dan Williams
[not found] ` <CAA9_cmffnH0CH+3DaUW3ytVnRWbZCHa1VcAfWgwMCfbncN_QcA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-01-04 5:28 ` Dave Young
2017-01-04 14:25 ` Peter Jones
2017-01-04 17:45 ` Nicolai Stange
2017-01-04 18:40 ` Dan Williams
2016-09-09 15:18 ` [PATCH 09/29] efi/runtime-map: Use efi.memmap directly instead of a copy Matt Fleming
2016-09-09 15:18 ` [PATCH 11/29] x86/efi-bgrt: Use efi_mem_reserve() to avoid copying image data Matt Fleming
2016-09-09 15:18 ` Matt Fleming [this message]
2016-09-09 15:18 ` [PATCH 16/29] efi: Replace runtime services spinlock with semaphore Matt Fleming
2016-09-09 15:18 ` [PATCH 17/29] x86/efi: Initialize status to ensure garbage is not returned on small size Matt Fleming
2016-09-09 15:18 ` [PATCH 19/29] lib/ucs2_string: Speed up ucs2_utf8size() Matt Fleming
2016-09-09 15:18 ` [PATCH 21/29] fs/efivarfs: Fix double kfree() in error path Matt Fleming
2016-09-09 15:18 ` [PATCH 22/29] x86/efi: Remove unused find_bits() function Matt Fleming
2016-09-09 15:18 ` [PATCH 23/29] efi/arm64: Add debugfs node to dump UEFI runtime page tables Matt Fleming
2016-09-09 15:18 ` [PATCH 25/29] efi: Add efi_test driver for exporting UEFI runtime service interfaces Matt Fleming
[not found] ` <20160909151851.27577-1-matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
2016-09-09 15:18 ` [PATCH 02/29] x86/efi: Consolidate region mapping logic Matt Fleming
2016-09-09 15:18 ` [PATCH 04/29] efi: Add efi_memmap_init_late() for permanent EFI memmap Matt Fleming
2016-09-09 15:18 ` [PATCH 07/29] efi: Add efi_memmap_install() for installing new EFI memory maps Matt Fleming
2016-09-09 15:18 ` [PATCH 10/29] efi/esrt: Use efi_mem_reserve() and avoid a kmalloc() Matt Fleming
2016-09-09 15:18 ` [PATCH 12/29] efi/esrt: Use memremap not ioremap to access ESRT table in memory Matt Fleming
2016-09-09 15:18 ` [PATCH 13/29] efi/arm*: esrt: Add missing call to efi_esrt_init() Matt Fleming
2016-09-09 15:18 ` [PATCH 15/29] efi: Don't use spinlocks for efi vars Matt Fleming
2016-09-09 15:18 ` [PATCH 18/29] firmware-gsmi: Delete an unnecessary check before the function call "dma_pool_destroy" Matt Fleming
2016-09-09 15:18 ` [PATCH 20/29] x86/efi: Map in physical addresses in efi_map_region_fixed Matt Fleming
2016-09-09 15:18 ` [PATCH 24/29] x86/efi: Defer efi_esrt_init until after memblock_x86_fill Matt Fleming
2016-09-09 15:18 ` [PATCH 26/29] efi/arm64: Treat regions with WT/WC set but WB cleared as memory Matt Fleming
2016-09-09 15:18 ` [PATCH 28/29] x86/efi: Optimize away setup_gop32/64 if unused Matt Fleming
2016-09-12 10:58 ` [GIT PULL 00/29] EFI changes for v4.9 Matt Fleming
[not found] ` <20160912105813.GC3872-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
2016-09-12 11:42 ` Ingo Molnar
2016-09-09 15:18 ` [PATCH 27/29] x86/efi: Use kmalloc_array() in efi_call_phys_prolog() Matt Fleming
2016-09-09 15:18 ` [PATCH 29/29] x86/efi: Allow invocation of arbitrary boot services Matt Fleming
2016-09-13 18:32 ` [GIT PULL 00/29] EFI changes for v4.9 Ingo Molnar
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