summaryrefslogtreecommitdiff
path: root/lib
diff options
context:
space:
mode:
authorStephen Rothwell <sfr@canb.auug.org.au>2016-09-12 15:12:05 +1000
committerStephen Rothwell <sfr@canb.auug.org.au>2016-09-12 15:12:05 +1000
commit583e1baf28d083f1c9a1f76f2c5539bb064071e0 (patch)
tree22ecccfc4059291777e09cc8c628d8e741511fb3 /lib
parentea48cb38efed901148252a70654364797927e0a5 (diff)
parentd481e88ed55345bfdaea6d6b8295e0643d5f0932 (diff)
downloadlinux-next-583e1baf28d083f1c9a1f76f2c5539bb064071e0.tar.gz
Merge branch 'akpm-current/current'
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig7
-rw-r--r--lib/Makefile1
-rw-r--r--lib/crc64_ecma.c341
-rw-r--r--lib/kstrtox.c6
-rw-r--r--lib/nmi_backtrace.c42
-rw-r--r--lib/stackdepot.c6
-rw-r--r--lib/strncpy_from_user.c2
7 files changed, 387 insertions, 18 deletions
diff --git a/lib/Kconfig b/lib/Kconfig
index d79909dc01ec..9d188fbd856a 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -185,6 +185,13 @@ config CRC8
when they need to do cyclic redundancy check according CRC8
algorithm. Module will be called crc8.
+config CRC64_ECMA
+ tristate "CRC64 ECMA function"
+ help
+ This option provides CRC64 ECMA function. Drivers may select this
+ when they need to do cyclic redundancy check according to the CRC64
+ ECMA algorithm.
+
config AUDIT_GENERIC
bool
depends on AUDIT && !AUDIT_ARCH
diff --git a/lib/Makefile b/lib/Makefile
index 5dc77a8ec297..4d5272c04cf9 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -93,6 +93,7 @@ obj-$(CONFIG_CRC32) += crc32.o
obj-$(CONFIG_CRC7) += crc7.o
obj-$(CONFIG_LIBCRC32C) += libcrc32c.o
obj-$(CONFIG_CRC8) += crc8.o
+obj-$(CONFIG_CRC64_ECMA) += crc64_ecma.o
obj-$(CONFIG_GENERIC_ALLOCATOR) += genalloc.o
obj-$(CONFIG_842_COMPRESS) += 842/
diff --git a/lib/crc64_ecma.c b/lib/crc64_ecma.c
new file mode 100644
index 000000000000..41629ea5a60c
--- /dev/null
+++ b/lib/crc64_ecma.c
@@ -0,0 +1,341 @@
+/*
+ * Copyright 2013 Freescale Semiconductor Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * * Neither the name of Freescale Semiconductor nor the
+ * names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ *
+ * ALTERNATIVELY, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") as published by the Free Software
+ * Foundation, either version 2 of that License or (at your option) any
+ * later version.
+ *
+ * THIS SOFTWARE IS PROVIDED BY Freescale Semiconductor ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL Freescale Semiconductor BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/module.h>
+#include <linux/crc64_ecma.h>
+
+
+#define CRC64_BYTE_MASK 0xFF
+#define CRC64_TABLE_SIZE 256
+
+
+struct crc64_table {
+ u64 seed;
+ u64 table[CRC64_TABLE_SIZE];
+};
+
+
+static struct crc64_table CRC64_ECMA_182 = {
+ CRC64_DEFAULT_INITVAL,
+ {
+ 0x0000000000000000ULL,
+ 0xb32e4cbe03a75f6fULL,
+ 0xf4843657a840a05bULL,
+ 0x47aa7ae9abe7ff34ULL,
+ 0x7bd0c384ff8f5e33ULL,
+ 0xc8fe8f3afc28015cULL,
+ 0x8f54f5d357cffe68ULL,
+ 0x3c7ab96d5468a107ULL,
+ 0xf7a18709ff1ebc66ULL,
+ 0x448fcbb7fcb9e309ULL,
+ 0x0325b15e575e1c3dULL,
+ 0xb00bfde054f94352ULL,
+ 0x8c71448d0091e255ULL,
+ 0x3f5f08330336bd3aULL,
+ 0x78f572daa8d1420eULL,
+ 0xcbdb3e64ab761d61ULL,
+ 0x7d9ba13851336649ULL,
+ 0xceb5ed8652943926ULL,
+ 0x891f976ff973c612ULL,
+ 0x3a31dbd1fad4997dULL,
+ 0x064b62bcaebc387aULL,
+ 0xb5652e02ad1b6715ULL,
+ 0xf2cf54eb06fc9821ULL,
+ 0x41e11855055bc74eULL,
+ 0x8a3a2631ae2dda2fULL,
+ 0x39146a8fad8a8540ULL,
+ 0x7ebe1066066d7a74ULL,
+ 0xcd905cd805ca251bULL,
+ 0xf1eae5b551a2841cULL,
+ 0x42c4a90b5205db73ULL,
+ 0x056ed3e2f9e22447ULL,
+ 0xb6409f5cfa457b28ULL,
+ 0xfb374270a266cc92ULL,
+ 0x48190ecea1c193fdULL,
+ 0x0fb374270a266cc9ULL,
+ 0xbc9d3899098133a6ULL,
+ 0x80e781f45de992a1ULL,
+ 0x33c9cd4a5e4ecdceULL,
+ 0x7463b7a3f5a932faULL,
+ 0xc74dfb1df60e6d95ULL,
+ 0x0c96c5795d7870f4ULL,
+ 0xbfb889c75edf2f9bULL,
+ 0xf812f32ef538d0afULL,
+ 0x4b3cbf90f69f8fc0ULL,
+ 0x774606fda2f72ec7ULL,
+ 0xc4684a43a15071a8ULL,
+ 0x83c230aa0ab78e9cULL,
+ 0x30ec7c140910d1f3ULL,
+ 0x86ace348f355aadbULL,
+ 0x3582aff6f0f2f5b4ULL,
+ 0x7228d51f5b150a80ULL,
+ 0xc10699a158b255efULL,
+ 0xfd7c20cc0cdaf4e8ULL,
+ 0x4e526c720f7dab87ULL,
+ 0x09f8169ba49a54b3ULL,
+ 0xbad65a25a73d0bdcULL,
+ 0x710d64410c4b16bdULL,
+ 0xc22328ff0fec49d2ULL,
+ 0x85895216a40bb6e6ULL,
+ 0x36a71ea8a7ace989ULL,
+ 0x0adda7c5f3c4488eULL,
+ 0xb9f3eb7bf06317e1ULL,
+ 0xfe5991925b84e8d5ULL,
+ 0x4d77dd2c5823b7baULL,
+ 0x64b62bcaebc387a1ULL,
+ 0xd7986774e864d8ceULL,
+ 0x90321d9d438327faULL,
+ 0x231c512340247895ULL,
+ 0x1f66e84e144cd992ULL,
+ 0xac48a4f017eb86fdULL,
+ 0xebe2de19bc0c79c9ULL,
+ 0x58cc92a7bfab26a6ULL,
+ 0x9317acc314dd3bc7ULL,
+ 0x2039e07d177a64a8ULL,
+ 0x67939a94bc9d9b9cULL,
+ 0xd4bdd62abf3ac4f3ULL,
+ 0xe8c76f47eb5265f4ULL,
+ 0x5be923f9e8f53a9bULL,
+ 0x1c4359104312c5afULL,
+ 0xaf6d15ae40b59ac0ULL,
+ 0x192d8af2baf0e1e8ULL,
+ 0xaa03c64cb957be87ULL,
+ 0xeda9bca512b041b3ULL,
+ 0x5e87f01b11171edcULL,
+ 0x62fd4976457fbfdbULL,
+ 0xd1d305c846d8e0b4ULL,
+ 0x96797f21ed3f1f80ULL,
+ 0x2557339fee9840efULL,
+ 0xee8c0dfb45ee5d8eULL,
+ 0x5da24145464902e1ULL,
+ 0x1a083bacedaefdd5ULL,
+ 0xa9267712ee09a2baULL,
+ 0x955cce7fba6103bdULL,
+ 0x267282c1b9c65cd2ULL,
+ 0x61d8f8281221a3e6ULL,
+ 0xd2f6b4961186fc89ULL,
+ 0x9f8169ba49a54b33ULL,
+ 0x2caf25044a02145cULL,
+ 0x6b055fede1e5eb68ULL,
+ 0xd82b1353e242b407ULL,
+ 0xe451aa3eb62a1500ULL,
+ 0x577fe680b58d4a6fULL,
+ 0x10d59c691e6ab55bULL,
+ 0xa3fbd0d71dcdea34ULL,
+ 0x6820eeb3b6bbf755ULL,
+ 0xdb0ea20db51ca83aULL,
+ 0x9ca4d8e41efb570eULL,
+ 0x2f8a945a1d5c0861ULL,
+ 0x13f02d374934a966ULL,
+ 0xa0de61894a93f609ULL,
+ 0xe7741b60e174093dULL,
+ 0x545a57dee2d35652ULL,
+ 0xe21ac88218962d7aULL,
+ 0x5134843c1b317215ULL,
+ 0x169efed5b0d68d21ULL,
+ 0xa5b0b26bb371d24eULL,
+ 0x99ca0b06e7197349ULL,
+ 0x2ae447b8e4be2c26ULL,
+ 0x6d4e3d514f59d312ULL,
+ 0xde6071ef4cfe8c7dULL,
+ 0x15bb4f8be788911cULL,
+ 0xa6950335e42fce73ULL,
+ 0xe13f79dc4fc83147ULL,
+ 0x521135624c6f6e28ULL,
+ 0x6e6b8c0f1807cf2fULL,
+ 0xdd45c0b11ba09040ULL,
+ 0x9aefba58b0476f74ULL,
+ 0x29c1f6e6b3e0301bULL,
+ 0xc96c5795d7870f42ULL,
+ 0x7a421b2bd420502dULL,
+ 0x3de861c27fc7af19ULL,
+ 0x8ec62d7c7c60f076ULL,
+ 0xb2bc941128085171ULL,
+ 0x0192d8af2baf0e1eULL,
+ 0x4638a2468048f12aULL,
+ 0xf516eef883efae45ULL,
+ 0x3ecdd09c2899b324ULL,
+ 0x8de39c222b3eec4bULL,
+ 0xca49e6cb80d9137fULL,
+ 0x7967aa75837e4c10ULL,
+ 0x451d1318d716ed17ULL,
+ 0xf6335fa6d4b1b278ULL,
+ 0xb199254f7f564d4cULL,
+ 0x02b769f17cf11223ULL,
+ 0xb4f7f6ad86b4690bULL,
+ 0x07d9ba1385133664ULL,
+ 0x4073c0fa2ef4c950ULL,
+ 0xf35d8c442d53963fULL,
+ 0xcf273529793b3738ULL,
+ 0x7c0979977a9c6857ULL,
+ 0x3ba3037ed17b9763ULL,
+ 0x888d4fc0d2dcc80cULL,
+ 0x435671a479aad56dULL,
+ 0xf0783d1a7a0d8a02ULL,
+ 0xb7d247f3d1ea7536ULL,
+ 0x04fc0b4dd24d2a59ULL,
+ 0x3886b22086258b5eULL,
+ 0x8ba8fe9e8582d431ULL,
+ 0xcc0284772e652b05ULL,
+ 0x7f2cc8c92dc2746aULL,
+ 0x325b15e575e1c3d0ULL,
+ 0x8175595b76469cbfULL,
+ 0xc6df23b2dda1638bULL,
+ 0x75f16f0cde063ce4ULL,
+ 0x498bd6618a6e9de3ULL,
+ 0xfaa59adf89c9c28cULL,
+ 0xbd0fe036222e3db8ULL,
+ 0x0e21ac88218962d7ULL,
+ 0xc5fa92ec8aff7fb6ULL,
+ 0x76d4de52895820d9ULL,
+ 0x317ea4bb22bfdfedULL,
+ 0x8250e80521188082ULL,
+ 0xbe2a516875702185ULL,
+ 0x0d041dd676d77eeaULL,
+ 0x4aae673fdd3081deULL,
+ 0xf9802b81de97deb1ULL,
+ 0x4fc0b4dd24d2a599ULL,
+ 0xfceef8632775faf6ULL,
+ 0xbb44828a8c9205c2ULL,
+ 0x086ace348f355aadULL,
+ 0x34107759db5dfbaaULL,
+ 0x873e3be7d8faa4c5ULL,
+ 0xc094410e731d5bf1ULL,
+ 0x73ba0db070ba049eULL,
+ 0xb86133d4dbcc19ffULL,
+ 0x0b4f7f6ad86b4690ULL,
+ 0x4ce50583738cb9a4ULL,
+ 0xffcb493d702be6cbULL,
+ 0xc3b1f050244347ccULL,
+ 0x709fbcee27e418a3ULL,
+ 0x3735c6078c03e797ULL,
+ 0x841b8ab98fa4b8f8ULL,
+ 0xadda7c5f3c4488e3ULL,
+ 0x1ef430e13fe3d78cULL,
+ 0x595e4a08940428b8ULL,
+ 0xea7006b697a377d7ULL,
+ 0xd60abfdbc3cbd6d0ULL,
+ 0x6524f365c06c89bfULL,
+ 0x228e898c6b8b768bULL,
+ 0x91a0c532682c29e4ULL,
+ 0x5a7bfb56c35a3485ULL,
+ 0xe955b7e8c0fd6beaULL,
+ 0xaeffcd016b1a94deULL,
+ 0x1dd181bf68bdcbb1ULL,
+ 0x21ab38d23cd56ab6ULL,
+ 0x9285746c3f7235d9ULL,
+ 0xd52f0e859495caedULL,
+ 0x6601423b97329582ULL,
+ 0xd041dd676d77eeaaULL,
+ 0x636f91d96ed0b1c5ULL,
+ 0x24c5eb30c5374ef1ULL,
+ 0x97eba78ec690119eULL,
+ 0xab911ee392f8b099ULL,
+ 0x18bf525d915feff6ULL,
+ 0x5f1528b43ab810c2ULL,
+ 0xec3b640a391f4fadULL,
+ 0x27e05a6e926952ccULL,
+ 0x94ce16d091ce0da3ULL,
+ 0xd3646c393a29f297ULL,
+ 0x604a2087398eadf8ULL,
+ 0x5c3099ea6de60cffULL,
+ 0xef1ed5546e415390ULL,
+ 0xa8b4afbdc5a6aca4ULL,
+ 0x1b9ae303c601f3cbULL,
+ 0x56ed3e2f9e224471ULL,
+ 0xe5c372919d851b1eULL,
+ 0xa26908783662e42aULL,
+ 0x114744c635c5bb45ULL,
+ 0x2d3dfdab61ad1a42ULL,
+ 0x9e13b115620a452dULL,
+ 0xd9b9cbfcc9edba19ULL,
+ 0x6a978742ca4ae576ULL,
+ 0xa14cb926613cf817ULL,
+ 0x1262f598629ba778ULL,
+ 0x55c88f71c97c584cULL,
+ 0xe6e6c3cfcadb0723ULL,
+ 0xda9c7aa29eb3a624ULL,
+ 0x69b2361c9d14f94bULL,
+ 0x2e184cf536f3067fULL,
+ 0x9d36004b35545910ULL,
+ 0x2b769f17cf112238ULL,
+ 0x9858d3a9ccb67d57ULL,
+ 0xdff2a94067518263ULL,
+ 0x6cdce5fe64f6dd0cULL,
+ 0x50a65c93309e7c0bULL,
+ 0xe388102d33392364ULL,
+ 0xa4226ac498dedc50ULL,
+ 0x170c267a9b79833fULL,
+ 0xdcd7181e300f9e5eULL,
+ 0x6ff954a033a8c131ULL,
+ 0x28532e49984f3e05ULL,
+ 0x9b7d62f79be8616aULL,
+ 0xa707db9acf80c06dULL,
+ 0x14299724cc279f02ULL,
+ 0x5383edcd67c06036ULL,
+ 0xe0ada17364673f59ULL
+ }
+};
+
+
+/*
+ * crc64_ecma_seed - Initializes the CRC64 ECMA seed.
+ */
+u64 crc64_ecma_seed(void)
+{
+ return CRC64_ECMA_182.seed;
+}
+EXPORT_SYMBOL(crc64_ecma_seed);
+
+/*
+ * crc64_ecma - Computes the 64 bit ECMA CRC.
+ *
+ * pdata: pointer to the data to compute checksum for.
+ * nbytes: number of bytes in data buffer.
+ * seed: CRC seed.
+ */
+u64 crc64_ecma(u8 const *pdata, u32 nbytes, u64 seed)
+{
+ unsigned int i;
+ u64 crc = seed;
+
+ for (i = 0; i < nbytes; i++)
+ crc = CRC64_ECMA_182.table[(crc ^ pdata[i]) & CRC64_BYTE_MASK] ^
+ (crc >> 8);
+
+ return crc;
+}
+EXPORT_SYMBOL(crc64_ecma);
+
+MODULE_DESCRIPTION("CRC64 ECMA function");
+MODULE_AUTHOR("Freescale Semiconductor Inc.");
+MODULE_LICENSE("GPL");
diff --git a/lib/kstrtox.c b/lib/kstrtox.c
index d8a5cf66c316..b8e2080c1a47 100644
--- a/lib/kstrtox.c
+++ b/lib/kstrtox.c
@@ -48,11 +48,9 @@ unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long
{
unsigned long long res;
unsigned int rv;
- int overflow;
res = 0;
rv = 0;
- overflow = 0;
while (*s) {
unsigned int val;
@@ -71,15 +69,13 @@ unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long
*/
if (unlikely(res & (~0ull << 60))) {
if (res > div_u64(ULLONG_MAX - val, base))
- overflow = 1;
+ rv |= KSTRTOX_OVERFLOW;
}
res = res * base + val;
rv++;
s++;
}
*p = res;
- if (overflow)
- rv |= KSTRTOX_OVERFLOW;
return rv;
}
diff --git a/lib/nmi_backtrace.c b/lib/nmi_backtrace.c
index 26caf51cc238..75554754eadf 100644
--- a/lib/nmi_backtrace.c
+++ b/lib/nmi_backtrace.c
@@ -16,21 +16,23 @@
#include <linux/delay.h>
#include <linux/kprobes.h>
#include <linux/nmi.h>
+#include <linux/cpu.h>
-#ifdef arch_trigger_all_cpu_backtrace
+#ifdef arch_trigger_cpumask_backtrace
/* For reliability, we're prepared to waste bits here. */
static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly;
-/* "in progress" flag of arch_trigger_all_cpu_backtrace */
+/* "in progress" flag of arch_trigger_cpumask_backtrace */
static unsigned long backtrace_flag;
/*
- * When raise() is called it will be is passed a pointer to the
+ * When raise() is called it will be passed a pointer to the
* backtrace_mask. Architectures that call nmi_cpu_backtrace()
* directly from their raise() functions may rely on the mask
* they are passed being updated as a side effect of this call.
*/
-void nmi_trigger_all_cpu_backtrace(bool include_self,
+void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
+ bool exclude_self,
void (*raise)(cpumask_t *mask))
{
int i, this_cpu = get_cpu();
@@ -44,13 +46,22 @@ void nmi_trigger_all_cpu_backtrace(bool include_self,
return;
}
- cpumask_copy(to_cpumask(backtrace_mask), cpu_online_mask);
- if (!include_self)
+ cpumask_copy(to_cpumask(backtrace_mask), mask);
+ if (exclude_self)
cpumask_clear_cpu(this_cpu, to_cpumask(backtrace_mask));
+ /*
+ * Don't try to send an NMI to this cpu; it may work on some
+ * architectures, but on others it may not, and we'll get
+ * information at least as useful just by doing a dump_stack() here.
+ * Note that nmi_cpu_backtrace(NULL) will clear the cpu bit.
+ */
+ if (cpumask_test_cpu(this_cpu, to_cpumask(backtrace_mask)))
+ nmi_cpu_backtrace(NULL);
+
if (!cpumask_empty(to_cpumask(backtrace_mask))) {
- pr_info("Sending NMI to %s CPUs:\n",
- (include_self ? "all" : "other"));
+ pr_info("Sending NMI from CPU %d to CPUs %*pbl:\n",
+ this_cpu, nr_cpumask_bits, to_cpumask(backtrace_mask));
raise(to_cpumask(backtrace_mask));
}
@@ -77,11 +88,16 @@ bool nmi_cpu_backtrace(struct pt_regs *regs)
int cpu = smp_processor_id();
if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
- pr_warn("NMI backtrace for cpu %d\n", cpu);
- if (regs)
- show_regs(regs);
- else
- dump_stack();
+ if (regs && cpu_in_idle(instruction_pointer(regs))) {
+ pr_warn("NMI backtrace for cpu %d skipped: idling at pc %#lx\n",
+ cpu, instruction_pointer(regs));
+ } else {
+ pr_warn("NMI backtrace for cpu %d\n", cpu);
+ if (regs)
+ show_regs(regs);
+ else
+ dump_stack();
+ }
cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask));
return true;
}
diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index 60f77f1d470a..da015cda4f4b 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -243,6 +243,12 @@ depot_stack_handle_t depot_save_stack(struct stack_trace *trace,
alloc_flags &= ~GFP_ZONEMASK;
alloc_flags &= (GFP_ATOMIC | GFP_KERNEL);
alloc_flags |= __GFP_NOWARN;
+ /*
+ * Avoid using current->mempolicy which may already have
+ * been freed -- we may be in the process of saving the
+ * stack for exactly that __mpol_put() call.
+ */
+ alloc_flags |= __GFP_THISNODE;
page = alloc_pages(alloc_flags, STACK_ALLOC_ORDER);
if (page)
prealloc = page_address(page);
diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c
index 9c5fe8110413..7e35fc450c5b 100644
--- a/lib/strncpy_from_user.c
+++ b/lib/strncpy_from_user.c
@@ -1,6 +1,7 @@
#include <linux/compiler.h>
#include <linux/export.h>
#include <linux/kasan-checks.h>
+#include <linux/thread_info.h>
#include <linux/uaccess.h>
#include <linux/kernel.h>
#include <linux/errno.h>
@@ -111,6 +112,7 @@ long strncpy_from_user(char *dst, const char __user *src, long count)
long retval;
kasan_check_write(dst, count);
+ check_object_size(dst, count, false);
user_access_begin();
retval = do_strncpy_from_user(dst, src, count, max);
user_access_end();