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authorLinus Torvalds <torvalds@linux-foundation.org>2016-01-21 12:32:08 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-21 12:32:08 -0800
commiteae21770b4fed5597623aad0d618190fa60426ff (patch)
tree23c59fb7a33e93a79525e2b10d56df54d40049d1 /lib
parente9f57ebcba563e0cd532926cab83c92bb4d79360 (diff)
parent9f273c24ec5f4a6f785bb83e931b3808a07b459e (diff)
downloadlinux-eae21770b4fed5597623aad0d618190fa60426ff.tar.bz2
Merge branch 'akpm' (patches from Andrew)
Merge third patch-bomb from Andrew Morton: "I'm pretty much done for -rc1 now: - the rest of MM, basically - lib/ updates - checkpatch, epoll, hfs, fatfs, ptrace, coredump, exit - cpu_mask simplifications - kexec, rapidio, MAINTAINERS etc, etc. - more dma-mapping cleanups/simplifications from hch" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (109 commits) MAINTAINERS: add/fix git URLs for various subsystems mm: memcontrol: add "sock" to cgroup2 memory.stat mm: memcontrol: basic memory statistics in cgroup2 memory controller mm: memcontrol: do not uncharge old page in page cache replacement Documentation: cgroup: add memory.swap.{current,max} description mm: free swap cache aggressively if memcg swap is full mm: vmscan: do not scan anon pages if memcg swap limit is hit swap.h: move memcg related stuff to the end of the file mm: memcontrol: replace mem_cgroup_lruvec_online with mem_cgroup_online mm: vmscan: pass memcg to get_scan_count() mm: memcontrol: charge swap to cgroup2 mm: memcontrol: clean up alloc, online, offline, free functions mm: memcontrol: flatten struct cg_proto mm: memcontrol: rein in the CONFIG space madness net: drop tcp_memcontrol.c mm: memcontrol: introduce CONFIG_MEMCG_LEGACY_KMEM mm: memcontrol: allow to disable kmem accounting for cgroup2 mm: memcontrol: account "kmem" consumers in cgroup2 memory controller mm: memcontrol: move kmem accounting code to CONFIG_MEMCG mm: memcontrol: separate kmem code from legacy tcp accounting code ...
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.debug2
-rw-r--r--lib/Kconfig.ubsan29
-rw-r--r--lib/Makefile7
-rw-r--r--lib/iomap_copy.c21
-rw-r--r--lib/libcrc32c.c1
-rw-r--r--lib/string_helpers.c63
-rw-r--r--lib/test_hexdump.c (renamed from lib/test-hexdump.c)146
-rw-r--r--lib/ubsan.c456
-rw-r--r--lib/ubsan.h84
9 files changed, 743 insertions, 66 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 7d0b49c536c5..ecb9e75614bf 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1893,6 +1893,8 @@ source "samples/Kconfig"
source "lib/Kconfig.kgdb"
+source "lib/Kconfig.ubsan"
+
config ARCH_HAS_DEVMEM_IS_ALLOWED
bool
diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan
new file mode 100644
index 000000000000..49518fb48cab
--- /dev/null
+++ b/lib/Kconfig.ubsan
@@ -0,0 +1,29 @@
+config ARCH_HAS_UBSAN_SANITIZE_ALL
+ bool
+
+config UBSAN
+ bool "Undefined behaviour sanity checker"
+ help
+ This option enables undefined behaviour sanity checker
+ Compile-time instrumentation is used to detect various undefined
+ behaviours in runtime. Various types of checks may be enabled
+ via boot parameter ubsan_handle (see: Documentation/ubsan.txt).
+
+config UBSAN_SANITIZE_ALL
+ bool "Enable instrumentation for the entire kernel"
+ depends on UBSAN
+ depends on ARCH_HAS_UBSAN_SANITIZE_ALL
+ default y
+ help
+ This option activates instrumentation for the entire kernel.
+ If you don't enable this option, you have to explicitly specify
+ UBSAN_SANITIZE := y for the files/directories you want to check for UB.
+
+config UBSAN_ALIGNMENT
+ bool "Enable checking of pointers alignment"
+ depends on UBSAN
+ default y if !HAVE_EFFICIENT_UNALIGNED_ACCESS
+ help
+ This option enables detection of unaligned memory accesses.
+ Enabling this option on architectures that support unalligned
+ accesses may produce a lot of false positives.
diff --git a/lib/Makefile b/lib/Makefile
index 180dd4d0dd41..2d4bc33d09b4 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -31,7 +31,7 @@ obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
obj-y += string_helpers.o
obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o
obj-y += hexdump.o
-obj-$(CONFIG_TEST_HEXDUMP) += test-hexdump.o
+obj-$(CONFIG_TEST_HEXDUMP) += test_hexdump.o
obj-y += kstrtox.o
obj-$(CONFIG_TEST_BPF) += test_bpf.o
obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o
@@ -154,7 +154,7 @@ obj-$(CONFIG_GLOB) += glob.o
obj-$(CONFIG_MPILIB) += mpi/
obj-$(CONFIG_SIGNATURE) += digsig.o
-obj-$(CONFIG_CLZ_TAB) += clz_tab.o
+lib-$(CONFIG_CLZ_TAB) += clz_tab.o
obj-$(CONFIG_DDR) += jedec_ddr_data.o
@@ -209,3 +209,6 @@ quiet_cmd_build_OID_registry = GEN $@
clean-files += oid_registry_data.c
obj-$(CONFIG_UCS2_STRING) += ucs2_string.o
+obj-$(CONFIG_UBSAN) += ubsan.o
+
+UBSAN_SANITIZE_ubsan.o := n
diff --git a/lib/iomap_copy.c b/lib/iomap_copy.c
index 4527e751b5e0..b8f1d6cbb200 100644
--- a/lib/iomap_copy.c
+++ b/lib/iomap_copy.c
@@ -42,6 +42,27 @@ void __attribute__((weak)) __iowrite32_copy(void __iomem *to,
EXPORT_SYMBOL_GPL(__iowrite32_copy);
/**
+ * __ioread32_copy - copy data from MMIO space, in 32-bit units
+ * @to: destination (must be 32-bit aligned)
+ * @from: source, in MMIO space (must be 32-bit aligned)
+ * @count: number of 32-bit quantities to copy
+ *
+ * Copy data from MMIO space to kernel space, in units of 32 bits at a
+ * time. Order of access is not guaranteed, nor is a memory barrier
+ * performed afterwards.
+ */
+void __ioread32_copy(void *to, const void __iomem *from, size_t count)
+{
+ u32 *dst = to;
+ const u32 __iomem *src = from;
+ const u32 __iomem *end = src + count;
+
+ while (src < end)
+ *dst++ = __raw_readl(src++);
+}
+EXPORT_SYMBOL_GPL(__ioread32_copy);
+
+/**
* __iowrite64_copy - copy data to MMIO space, in 64-bit or 32-bit units
* @to: destination, in MMIO space (must be 64-bit aligned)
* @from: source (must be 64-bit aligned)
diff --git a/lib/libcrc32c.c b/lib/libcrc32c.c
index 6a08ce7d6adc..31ce853fbfb1 100644
--- a/lib/libcrc32c.c
+++ b/lib/libcrc32c.c
@@ -36,6 +36,7 @@
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/crc32c.h>
static struct crypto_shash *tfm;
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 5939f63d90cd..5c88204b6f1f 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -43,50 +43,73 @@ void string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
[STRING_UNITS_10] = 1000,
[STRING_UNITS_2] = 1024,
};
- int i, j;
- u32 remainder = 0, sf_cap, exp;
+ static const unsigned int rounding[] = { 500, 50, 5 };
+ int i = 0, j;
+ u32 remainder = 0, sf_cap;
char tmp[8];
const char *unit;
tmp[0] = '\0';
- i = 0;
- if (!size)
+
+ if (blk_size == 0)
+ size = 0;
+ if (size == 0)
goto out;
- while (blk_size >= divisor[units]) {
- remainder = do_div(blk_size, divisor[units]);
+ /* This is Napier's algorithm. Reduce the original block size to
+ *
+ * coefficient * divisor[units]^i
+ *
+ * we do the reduction so both coefficients are just under 32 bits so
+ * that multiplying them together won't overflow 64 bits and we keep
+ * as much precision as possible in the numbers.
+ *
+ * Note: it's safe to throw away the remainders here because all the
+ * precision is in the coefficients.
+ */
+ while (blk_size >> 32) {
+ do_div(blk_size, divisor[units]);
i++;
}
- exp = divisor[units] / (u32)blk_size;
- /*
- * size must be strictly greater than exp here to ensure that remainder
- * is greater than divisor[units] coming out of the if below.
- */
- if (size > exp) {
- remainder = do_div(size, divisor[units]);
- remainder *= blk_size;
+ while (size >> 32) {
+ do_div(size, divisor[units]);
i++;
- } else {
- remainder *= size;
}
+ /* now perform the actual multiplication keeping i as the sum of the
+ * two logarithms */
size *= blk_size;
- size += remainder / divisor[units];
- remainder %= divisor[units];
+ /* and logarithmically reduce it until it's just under the divisor */
while (size >= divisor[units]) {
remainder = do_div(size, divisor[units]);
i++;
}
+ /* work out in j how many digits of precision we need from the
+ * remainder */
sf_cap = size;
for (j = 0; sf_cap*10 < 1000; j++)
sf_cap *= 10;
- if (j) {
+ if (units == STRING_UNITS_2) {
+ /* express the remainder as a decimal. It's currently the
+ * numerator of a fraction whose denominator is
+ * divisor[units], which is 1 << 10 for STRING_UNITS_2 */
remainder *= 1000;
- remainder /= divisor[units];
+ remainder >>= 10;
+ }
+
+ /* add a 5 to the digit below what will be printed to ensure
+ * an arithmetical round up and carry it through to size */
+ remainder += rounding[j];
+ if (remainder >= 1000) {
+ remainder -= 1000;
+ size += 1;
+ }
+
+ if (j) {
snprintf(tmp, sizeof(tmp), ".%03u", remainder);
tmp[j+1] = '\0';
}
diff --git a/lib/test-hexdump.c b/lib/test_hexdump.c
index 5241df36eedf..3f415d8101f3 100644
--- a/lib/test-hexdump.c
+++ b/lib/test_hexdump.c
@@ -42,19 +42,21 @@ static const char * const test_data_8_le[] __initconst = {
"e9ac0f9cad319ca6", "0cafb1439919d14c",
};
-static void __init test_hexdump(size_t len, int rowsize, int groupsize,
- bool ascii)
+#define FILL_CHAR '#'
+
+static unsigned total_tests __initdata;
+static unsigned failed_tests __initdata;
+
+static void __init test_hexdump_prepare_test(size_t len, int rowsize,
+ int groupsize, char *test,
+ size_t testlen, bool ascii)
{
- char test[32 * 3 + 2 + 32 + 1];
- char real[32 * 3 + 2 + 32 + 1];
char *p;
const char * const *result;
size_t l = len;
int gs = groupsize, rs = rowsize;
unsigned int i;
- hex_dump_to_buffer(data_b, l, rs, gs, real, sizeof(real), ascii);
-
if (rs != 16 && rs != 32)
rs = 16;
@@ -73,8 +75,6 @@ static void __init test_hexdump(size_t len, int rowsize, int groupsize,
else
result = test_data_1_le;
- memset(test, ' ', sizeof(test));
-
/* hex dump */
p = test;
for (i = 0; i < l / gs; i++) {
@@ -82,24 +82,49 @@ static void __init test_hexdump(size_t len, int rowsize, int groupsize,
size_t amount = strlen(q);
strncpy(p, q, amount);
- p += amount + 1;
+ p += amount;
+
+ *p++ = ' ';
}
if (i)
p--;
/* ASCII part */
if (ascii) {
- p = test + rs * 2 + rs / gs + 1;
+ do {
+ *p++ = ' ';
+ } while (p < test + rs * 2 + rs / gs + 1);
+
strncpy(p, data_a, l);
p += l;
}
*p = '\0';
+}
- if (strcmp(test, real)) {
+#define TEST_HEXDUMP_BUF_SIZE (32 * 3 + 2 + 32 + 1)
+
+static void __init test_hexdump(size_t len, int rowsize, int groupsize,
+ bool ascii)
+{
+ char test[TEST_HEXDUMP_BUF_SIZE];
+ char real[TEST_HEXDUMP_BUF_SIZE];
+
+ total_tests++;
+
+ memset(real, FILL_CHAR, sizeof(real));
+ hex_dump_to_buffer(data_b, len, rowsize, groupsize, real, sizeof(real),
+ ascii);
+
+ memset(test, FILL_CHAR, sizeof(test));
+ test_hexdump_prepare_test(len, rowsize, groupsize, test, sizeof(test),
+ ascii);
+
+ if (memcmp(test, real, TEST_HEXDUMP_BUF_SIZE)) {
pr_err("Len: %zu row: %d group: %d\n", len, rowsize, groupsize);
pr_err("Result: '%s'\n", real);
pr_err("Expect: '%s'\n", test);
+ failed_tests++;
}
}
@@ -114,52 +139,72 @@ static void __init test_hexdump_set(int rowsize, bool ascii)
test_hexdump(len, rowsize, 1, ascii);
}
-static void __init test_hexdump_overflow(bool ascii)
+static void __init test_hexdump_overflow(size_t buflen, size_t len,
+ int rowsize, int groupsize,
+ bool ascii)
{
- char buf[56];
- const char *t = test_data_1_le[0];
- size_t l = get_random_int() % sizeof(buf);
+ char test[TEST_HEXDUMP_BUF_SIZE];
+ char buf[TEST_HEXDUMP_BUF_SIZE];
+ int rs = rowsize, gs = groupsize;
+ int ae, he, e, f, r;
bool a;
- int e, r;
- memset(buf, ' ', sizeof(buf));
+ total_tests++;
+
+ memset(buf, FILL_CHAR, sizeof(buf));
- r = hex_dump_to_buffer(data_b, 1, 16, 1, buf, l, ascii);
+ r = hex_dump_to_buffer(data_b, len, rs, gs, buf, buflen, ascii);
+
+ /*
+ * Caller must provide the data length multiple of groupsize. The
+ * calculations below are made with that assumption in mind.
+ */
+ ae = rs * 2 /* hex */ + rs / gs /* spaces */ + 1 /* space */ + len /* ascii */;
+ he = (gs * 2 /* hex */ + 1 /* space */) * len / gs - 1 /* no trailing space */;
if (ascii)
- e = 50;
+ e = ae;
else
- e = 2;
- buf[e + 2] = '\0';
-
- if (!l) {
- a = r == e && buf[0] == ' ';
- } else if (l < 3) {
- a = r == e && buf[0] == '\0';
- } else if (l < 4) {
- a = r == e && !strcmp(buf, t);
- } else if (ascii) {
- if (l < 51)
- a = r == e && buf[l - 1] == '\0' && buf[l - 2] == ' ';
- else
- a = r == e && buf[50] == '\0' && buf[49] == '.';
- } else {
- a = r == e && buf[e] == '\0';
+ e = he;
+
+ f = min_t(int, e + 1, buflen);
+ if (buflen) {
+ test_hexdump_prepare_test(len, rs, gs, test, sizeof(test), ascii);
+ test[f - 1] = '\0';
}
+ memset(test + f, FILL_CHAR, sizeof(test) - f);
+
+ a = r == e && !memcmp(test, buf, TEST_HEXDUMP_BUF_SIZE);
+
+ buf[sizeof(buf) - 1] = '\0';
if (!a) {
- pr_err("Len: %zu rc: %u strlen: %zu\n", l, r, strlen(buf));
- pr_err("Result: '%s'\n", buf);
+ pr_err("Len: %zu buflen: %zu strlen: %zu\n",
+ len, buflen, strnlen(buf, sizeof(buf)));
+ pr_err("Result: %d '%s'\n", r, buf);
+ pr_err("Expect: %d '%s'\n", e, test);
+ failed_tests++;
}
}
+static void __init test_hexdump_overflow_set(size_t buflen, bool ascii)
+{
+ unsigned int i = 0;
+ int rs = (get_random_int() % 2 + 1) * 16;
+
+ do {
+ int gs = 1 << i;
+ size_t len = get_random_int() % rs + gs;
+
+ test_hexdump_overflow(buflen, rounddown(len, gs), rs, gs, ascii);
+ } while (i++ < 3);
+}
+
static int __init test_hexdump_init(void)
{
unsigned int i;
int rowsize;
- pr_info("Running tests...\n");
-
rowsize = (get_random_int() % 2 + 1) * 16;
for (i = 0; i < 16; i++)
test_hexdump_set(rowsize, false);
@@ -168,13 +213,26 @@ static int __init test_hexdump_init(void)
for (i = 0; i < 16; i++)
test_hexdump_set(rowsize, true);
- for (i = 0; i < 16; i++)
- test_hexdump_overflow(false);
+ for (i = 0; i <= TEST_HEXDUMP_BUF_SIZE; i++)
+ test_hexdump_overflow_set(i, false);
- for (i = 0; i < 16; i++)
- test_hexdump_overflow(true);
+ for (i = 0; i <= TEST_HEXDUMP_BUF_SIZE; i++)
+ test_hexdump_overflow_set(i, true);
+
+ if (failed_tests == 0)
+ pr_info("all %u tests passed\n", total_tests);
+ else
+ pr_err("failed %u out of %u tests\n", failed_tests, total_tests);
- return -EINVAL;
+ return failed_tests ? -EINVAL : 0;
}
module_init(test_hexdump_init);
+
+static void __exit test_hexdump_exit(void)
+{
+ /* do nothing */
+}
+module_exit(test_hexdump_exit);
+
+MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
MODULE_LICENSE("Dual BSD/GPL");
diff --git a/lib/ubsan.c b/lib/ubsan.c
new file mode 100644
index 000000000000..8799ae5e2e42
--- /dev/null
+++ b/lib/ubsan.c
@@ -0,0 +1,456 @@
+/*
+ * UBSAN error reporting functions
+ *
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/bitops.h>
+#include <linux/bug.h>
+#include <linux/ctype.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+
+#include "ubsan.h"
+
+const char *type_check_kinds[] = {
+ "load of",
+ "store to",
+ "reference binding to",
+ "member access within",
+ "member call on",
+ "constructor call on",
+ "downcast of",
+ "downcast of"
+};
+
+#define REPORTED_BIT 31
+
+#if (BITS_PER_LONG == 64) && defined(__BIG_ENDIAN)
+#define COLUMN_MASK (~(1U << REPORTED_BIT))
+#define LINE_MASK (~0U)
+#else
+#define COLUMN_MASK (~0U)
+#define LINE_MASK (~(1U << REPORTED_BIT))
+#endif
+
+#define VALUE_LENGTH 40
+
+static bool was_reported(struct source_location *location)
+{
+ return test_and_set_bit(REPORTED_BIT, &location->reported);
+}
+
+static void print_source_location(const char *prefix,
+ struct source_location *loc)
+{
+ pr_err("%s %s:%d:%d\n", prefix, loc->file_name,
+ loc->line & LINE_MASK, loc->column & COLUMN_MASK);
+}
+
+static bool suppress_report(struct source_location *loc)
+{
+ return current->in_ubsan || was_reported(loc);
+}
+
+static bool type_is_int(struct type_descriptor *type)
+{
+ return type->type_kind == type_kind_int;
+}
+
+static bool type_is_signed(struct type_descriptor *type)
+{
+ WARN_ON(!type_is_int(type));
+ return type->type_info & 1;
+}
+
+static unsigned type_bit_width(struct type_descriptor *type)
+{
+ return 1 << (type->type_info >> 1);
+}
+
+static bool is_inline_int(struct type_descriptor *type)
+{
+ unsigned inline_bits = sizeof(unsigned long)*8;
+ unsigned bits = type_bit_width(type);
+
+ WARN_ON(!type_is_int(type));
+
+ return bits <= inline_bits;
+}
+
+static s_max get_signed_val(struct type_descriptor *type, unsigned long val)
+{
+ if (is_inline_int(type)) {
+ unsigned extra_bits = sizeof(s_max)*8 - type_bit_width(type);
+ return ((s_max)val) << extra_bits >> extra_bits;
+ }
+
+ if (type_bit_width(type) == 64)
+ return *(s64 *)val;
+
+ return *(s_max *)val;
+}
+
+static bool val_is_negative(struct type_descriptor *type, unsigned long val)
+{
+ return type_is_signed(type) && get_signed_val(type, val) < 0;
+}
+
+static u_max get_unsigned_val(struct type_descriptor *type, unsigned long val)
+{
+ if (is_inline_int(type))
+ return val;
+
+ if (type_bit_width(type) == 64)
+ return *(u64 *)val;
+
+ return *(u_max *)val;
+}
+
+static void val_to_string(char *str, size_t size, struct type_descriptor *type,
+ unsigned long value)
+{
+ if (type_is_int(type)) {
+ if (type_bit_width(type) == 128) {
+#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)
+ u_max val = get_unsigned_val(type, value);
+
+ scnprintf(str, size, "0x%08x%08x%08x%08x",
+ (u32)(val >> 96),
+ (u32)(val >> 64),
+ (u32)(val >> 32),
+ (u32)(val));
+#else
+ WARN_ON(1);
+#endif
+ } else if (type_is_signed(type)) {
+ scnprintf(str, size, "%lld",
+ (s64)get_signed_val(type, value));
+ } else {
+ scnprintf(str, size, "%llu",
+ (u64)get_unsigned_val(type, value));
+ }
+ }
+}
+
+static bool location_is_valid(struct source_location *loc)
+{
+ return loc->file_name != NULL;
+}
+
+static DEFINE_SPINLOCK(report_lock);
+
+static void ubsan_prologue(struct source_location *location,
+ unsigned long *flags)
+{
+ current->in_ubsan++;
+ spin_lock_irqsave(&report_lock, *flags);
+
+ pr_err("========================================"
+ "========================================\n");
+ print_source_location("UBSAN: Undefined behaviour in", location);
+}
+
+static void ubsan_epilogue(unsigned long *flags)
+{
+ dump_stack();
+ pr_err("========================================"
+ "========================================\n");
+ spin_unlock_irqrestore(&report_lock, *flags);
+ current->in_ubsan--;
+}
+
+static void handle_overflow(struct overflow_data *data, unsigned long lhs,
+ unsigned long rhs, char op)
+{
+
+ struct type_descriptor *type = data->type;
+ unsigned long flags;
+ char lhs_val_str[VALUE_LENGTH];
+ char rhs_val_str[VALUE_LENGTH];
+
+ if (suppress_report(&data->location))
+ return;
+
+ ubsan_prologue(&data->location, &flags);
+
+ val_to_string(lhs_val_str, sizeof(lhs_val_str), type, lhs);
+ val_to_string(rhs_val_str, sizeof(rhs_val_str), type, rhs);
+ pr_err("%s integer overflow:\n",
+ type_is_signed(type) ? "signed" : "unsigned");
+ pr_err("%s %c %s cannot be represented in type %s\n",
+ lhs_val_str,
+ op,
+ rhs_val_str,
+ type->type_name);
+
+ ubsan_epilogue(&flags);
+}
+
+void __ubsan_handle_add_overflow(struct overflow_data *data,
+ unsigned long lhs,
+ unsigned long rhs)
+{
+
+ handle_overflow(data, lhs, rhs, '+');
+}
+EXPORT_SYMBOL(__ubsan_handle_add_overflow);
+
+void __ubsan_handle_sub_overflow(struct overflow_data *data,
+ unsigned long lhs,
+ unsigned long rhs)
+{
+ handle_overflow(data, lhs, rhs, '-');
+}
+EXPORT_SYMBOL(__ubsan_handle_sub_overflow);
+
+void __ubsan_handle_mul_overflow(struct overflow_data *data,
+ unsigned long lhs,
+ unsigned long rhs)
+{
+ handle_overflow(data, lhs, rhs, '*');
+}
+EXPORT_SYMBOL(__ubsan_handle_mul_overflow);
+
+void __ubsan_handle_negate_overflow(struct overflow_data *data,
+ unsigned long old_val)
+{
+ unsigned long flags;
+ char old_val_str[VALUE_LENGTH];
+
+ if (suppress_report(&data->location))
+ return;
+
+ ubsan_prologue(&data->location, &flags);
+
+ val_to_string(old_val_str, sizeof(old_val_str), data->type, old_val);
+
+ pr_err("negation of %s cannot be represented in type %s:\n",
+ old_val_str, data->type->type_name);
+
+ ubsan_epilogue(&flags);
+}
+EXPORT_SYMBOL(__ubsan_handle_negate_overflow);
+
+
+void __ubsan_handle_divrem_overflow(struct overflow_data *data,
+ unsigned long lhs,
+ unsigned long rhs)
+{
+ unsigned long flags;
+ char rhs_val_str[VALUE_LENGTH];
+
+ if (suppress_report(&data->location))
+ return;
+
+ ubsan_prologue(&data->location, &flags);
+
+ val_to_string(rhs_val_str, sizeof(rhs_val_str), data->type, rhs);
+
+ if (type_is_signed(data->type) && get_signed_val(data->type, rhs) == -1)
+ pr_err("division of %s by -1 cannot be represented in type %s\n",
+ rhs_val_str, data->type->type_name);
+ else
+ pr_err("division by zero\n");
+
+ ubsan_epilogue(&flags);
+}
+EXPORT_SYMBOL(__ubsan_handle_divrem_overflow);
+
+static void handle_null_ptr_deref(struct type_mismatch_data *data)
+{
+ unsigned long flags;
+
+ if (suppress_report(&data->location))
+ return;
+
+ ubsan_prologue(&data->location, &flags);
+
+ pr_err("%s null pointer of type %s\n",
+ type_check_kinds[data->type_check_kind],
+ data->type->type_name);
+
+ ubsan_epilogue(&flags);
+}
+
+static void handle_missaligned_access(struct type_mismatch_data *data,
+ unsigned long ptr)
+{
+ unsigned long flags;
+
+ if (suppress_report(&data->location))
+ return;
+
+ ubsan_prologue(&data->location, &flags);
+
+ pr_err("%s misaligned address %p for type %s\n",
+ type_check_kinds[data->type_check_kind],
+ (void *)ptr, data->type->type_name);
+ pr_err("which requires %ld byte alignment\n", data->alignment);
+
+ ubsan_epilogue(&flags);
+}
+
+static void handle_object_size_mismatch(struct type_mismatch_data *data,
+ unsigned long ptr)
+{
+ unsigned long flags;
+
+ if (suppress_report(&data->location))
+ return;
+
+ ubsan_prologue(&data->location, &flags);
+ pr_err("%s address %pk with insufficient space\n",
+ type_check_kinds[data->type_check_kind],
+ (void *) ptr);
+ pr_err("for an object of type %s\n", data->type->type_name);
+ ubsan_epilogue(&flags);
+}
+
+void __ubsan_handle_type_mismatch(struct type_mismatch_data *data,
+ unsigned long ptr)
+{
+
+ if (!ptr)
+ handle_null_ptr_deref(data);
+ else if (data->alignment && !IS_ALIGNED(ptr, data->alignment))
+ handle_missaligned_access(data, ptr);
+ else
+ handle_object_size_mismatch(data, ptr);
+}
+EXPORT_SYMBOL(__ubsan_handle_type_mismatch);
+
+void __ubsan_handle_nonnull_return(struct nonnull_return_data *data)
+{
+ unsigned long flags;
+
+ if (suppress_report(&data->location))
+ return;
+
+ ubsan_prologue(&data->location, &flags);
+
+ pr_err("null pointer returned from function declared to never return null\n");
+
+ if (location_is_valid(&data->attr_location))
+ print_source_location("returns_nonnull attribute specified in",
+ &data->attr_location);
+
+ ubsan_epilogue(&flags);
+}
+EXPORT_SYMBOL(__ubsan_handle_nonnull_return);
+
+void __ubsan_handle_vla_bound_not_positive(struct vla_bound_data *data,
+ unsigned long bound)
+{
+ unsigned long flags;
+ char bound_str[VALUE_LENGTH];
+
+ if (suppress_report(&data->location))
+ return;
+
+ ubsan_prologue(&data->location, &flags);
+
+ val_to_string(bound_str, sizeof(bound_str), data->type, bound);
+ pr_err("variable length array bound value %s <= 0\n", bound_str);
+
+ ubsan_epilogue(&flags);
+}
+EXPORT_SYMBOL(__ubsan_handle_vla_bound_not_positive);
+
+void __ubsan_handle_out_of_bounds(struct out_of_bounds_data *data,
+ unsigned long index)
+{
+ unsigned long flags;
+ char index_str[VALUE_LENGTH];
+
+ if (suppress_report(&data->location))
+ return;
+
+ ubsan_prologue(&data->location, &flags);
+
+ val_to_string(index_str, sizeof(index_str), data->index_type, index);
+ pr_err("index %s is out of range for type %s\n", index_str,
+ data->array_type->type_name);
+ ubsan_epilogue(&flags);
+}
+EXPORT_SYMBOL(__ubsan_handle_out_of_bounds);
+
+void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data,
+ unsigned long lhs, unsigned long rhs)
+{
+ unsigned long flags;
+ struct type_descriptor *rhs_type = data->rhs_type;
+ struct type_descriptor *lhs_type = data->lhs_type;
+ char rhs_str[VALUE_LENGTH];
+ char lhs_str[VALUE_LENGTH];
+
+ if (suppress_report(&data->location))
+ return;
+
+ ubsan_prologue(&data->location, &flags);
+
+ val_to_string(rhs_str, sizeof(rhs_str), rhs_type, rhs);
+ val_to_string(lhs_str, sizeof(lhs_str), lhs_type, lhs);
+
+ if (val_is_negative(rhs_type, rhs))
+ pr_err("shift exponent %s is negative\n", rhs_str);
+
+ else if (get_unsigned_val(rhs_type, rhs) >=
+ type_bit_width(lhs_type))
+ pr_err("shift exponent %s is too large for %u-bit type %s\n",
+ rhs_str,
+ type_bit_width(lhs_type),
+ lhs_type->type_name);
+ else if (val_is_negative(lhs_type, lhs))
+ pr_err("left shift of negative value %s\n",
+ lhs_str);
+ else
+ pr_err("left shift of %s by %s places cannot be"
+ " represented in type %s\n",
+ lhs_str, rhs_str,
+ lhs_type->type_name);
+
+ ubsan_epilogue(&flags);
+}
+EXPORT_SYMBOL(__ubsan_handle_shift_out_of_bounds);
+
+
+void __noreturn
+__ubsan_handle_builtin_unreachable(struct unreachable_data *data)
+{
+ unsigned long flags;
+
+ ubsan_prologue(&data->location, &flags);
+ pr_err("calling __builtin_unreachable()\n");
+ ubsan_epilogue(&flags);
+ panic("can't return from __builtin_unreachable()");
+}
+EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable);
+
+void __ubsan_handle_load_invalid_value(struct invalid_value_data *data,
+ unsigned long val)
+{
+ unsigned long flags;
+ char val_str[VALUE_LENGTH];
+
+ if (suppress_report(&data->location))
+ return;
+
+ ubsan_prologue(&data->location, &flags);
+
+ val_to_string(val_str, sizeof(val_str), data->type, val);
+
+ pr_err("load of value %s is not a valid value for type %s\n",
+ val_str, data->type->type_name);
+
+ ubsan_epilogue(&flags);
+}
+EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
diff --git a/lib/ubsan.h b/lib/ubsan.h
new file mode 100644
index 000000000000..b2d18d4a53f5
--- /dev/null
+++ b/lib/ubsan.h
@@ -0,0 +1,84 @@
+#ifndef _LIB_UBSAN_H
+#define _LIB_UBSAN_H
+
+enum {
+ type_kind_int = 0,
+ type_kind_float = 1,
+ type_unknown = 0xffff
+};
+
+struct type_descriptor {
+ u16 type_kind;
+ u16 type_info;
+ char type_name[1];
+};
+
+struct source_location {
+ const char *file_name;
+ union {
+ unsigned long reported;
+ struct {
+ u32 line;
+ u32 column;
+ };
+ };
+};
+
+struct overflow_data {
+ struct source_location location;
+ struct type_descriptor *type;
+};
+
+struct type_mismatch_data {
+ struct source_location location;
+ struct type_descriptor *type;
+ unsigned long alignment;
+ unsigned char type_check_kind;
+};
+
+struct nonnull_arg_data {
+ struct source_location location;
+ struct source_location attr_location;
+ int arg_index;
+};
+
+struct nonnull_return_data {
+ struct source_location location;
+ struct source_location attr_location;
+};
+
+struct vla_bound_data {
+ struct source_location location;
+ struct type_descriptor *type;
+};
+
+struct out_of_bounds_data {
+ struct source_location location;
+ struct type_descriptor *array_type;
+ struct type_descriptor *index_type;
+};
+
+struct shift_out_of_bounds_data {
+ struct source_location location;
+ struct type_descriptor *lhs_type;
+ struct type_descriptor *rhs_type;
+};
+
+struct unreachable_data {
+ struct source_location location;
+};
+
+struct invalid_value_data {
+ struct source_location location;
+ struct type_descriptor *type;
+};
+
+#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)
+typedef __int128 s_max;
+typedef unsigned __int128 u_max;
+#else
+typedef s64 s_max;
+typedef u64 u_max;
+#endif
+
+#endif