tools: bpf: make use of reallocarray
reallocarray() is a safer variant of realloc which checks for multiplication overflow in case of array allocation. Since it's not available in Glibc < 2.26 import kernel's overflow.h and add a static inline implementation when needed. Use feature detection to probe for existence of reallocarray. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jiong Wang <jiong.wang@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This commit is contained in:
Jakub Kicinski
Daniel Borkmann
parent
8d13406c02
commit
531b014e7a
|
|
@ -52,7 +52,7 @@ INSTALL ?= install
|
|||
RM ?= rm -f
|
||||
|
||||
FEATURE_USER = .bpftool
|
||||
FEATURE_TESTS = libbfd disassembler-four-args
|
||||
FEATURE_TESTS = libbfd disassembler-four-args reallocarray
|
||||
FEATURE_DISPLAY = libbfd disassembler-four-args
|
||||
|
||||
check_feat := 1
|
||||
|
|
@ -75,6 +75,10 @@ ifeq ($(feature-disassembler-four-args), 1)
|
|||
CFLAGS += -DDISASM_FOUR_ARGS_SIGNATURE
|
||||
endif
|
||||
|
||||
ifeq ($(feature-reallocarray), 0)
|
||||
CFLAGS += -DCOMPAT_NEED_REALLOCARRAY
|
||||
endif
|
||||
|
||||
include $(wildcard $(OUTPUT)*.d)
|
||||
|
||||
all: $(OUTPUT)bpftool
|
||||
|
|
|
|||
|
|
@ -42,6 +42,7 @@
|
|||
#include <linux/compiler.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/hashtable.h>
|
||||
#include <tools/libc_compat.h>
|
||||
|
||||
#include "json_writer.h"
|
||||
|
||||
|
|
|
|||
|
|
@ -35,6 +35,7 @@
|
|||
* POSSIBILITY OF SUCH DAMAGE.
|
||||
*/
|
||||
|
||||
#define _GNU_SOURCE
|
||||
#include <stdarg.h>
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
|
|
@ -66,9 +67,8 @@ void kernel_syms_load(struct dump_data *dd)
|
|||
while (!feof(fp)) {
|
||||
if (!fgets(buff, sizeof(buff), fp))
|
||||
break;
|
||||
tmp = realloc(dd->sym_mapping,
|
||||
(dd->sym_count + 1) *
|
||||
sizeof(*dd->sym_mapping));
|
||||
tmp = reallocarray(dd->sym_mapping, dd->sym_count + 1,
|
||||
sizeof(*dd->sym_mapping));
|
||||
if (!tmp) {
|
||||
out:
|
||||
free(dd->sym_mapping);
|
||||
|
|
|
|||
|
|
@ -14,6 +14,7 @@ FILES= \
|
|||
test-libaudit.bin \
|
||||
test-libbfd.bin \
|
||||
test-disassembler-four-args.bin \
|
||||
test-reallocarray.bin \
|
||||
test-liberty.bin \
|
||||
test-liberty-z.bin \
|
||||
test-cplus-demangle.bin \
|
||||
|
|
@ -204,6 +205,9 @@ $(OUTPUT)test-libbfd.bin:
|
|||
$(OUTPUT)test-disassembler-four-args.bin:
|
||||
$(BUILD) -DPACKAGE='"perf"' -lbfd -lopcodes
|
||||
|
||||
$(OUTPUT)test-reallocarray.bin:
|
||||
$(BUILD)
|
||||
|
||||
$(OUTPUT)test-liberty.bin:
|
||||
$(CC) $(CFLAGS) -Wall -Werror -o $@ test-libbfd.c -DPACKAGE='"perf"' $(LDFLAGS) -lbfd -ldl -liberty
|
||||
|
||||
|
|
|
|||
|
|
@ -0,0 +1,8 @@
|
|||
// SPDX-License-Identifier: GPL-2.0
|
||||
#define _GNU_SOURCE
|
||||
#include <stdlib.h>
|
||||
|
||||
int main(void)
|
||||
{
|
||||
return !!reallocarray(NULL, 1, 1);
|
||||
}
|
||||
|
|
@ -36,3 +36,7 @@
|
|||
#endif
|
||||
#define __printf(a, b) __attribute__((format(printf, a, b)))
|
||||
#define __scanf(a, b) __attribute__((format(scanf, a, b)))
|
||||
|
||||
#if GCC_VERSION >= 50100
|
||||
#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
|
||||
#endif
|
||||
|
|
|
|||
|
|
@ -0,0 +1,278 @@
|
|||
/* SPDX-License-Identifier: GPL-2.0 OR MIT */
|
||||
#ifndef __LINUX_OVERFLOW_H
|
||||
#define __LINUX_OVERFLOW_H
|
||||
|
||||
#include <linux/compiler.h>
|
||||
|
||||
/*
|
||||
* In the fallback code below, we need to compute the minimum and
|
||||
* maximum values representable in a given type. These macros may also
|
||||
* be useful elsewhere, so we provide them outside the
|
||||
* COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW block.
|
||||
*
|
||||
* It would seem more obvious to do something like
|
||||
*
|
||||
* #define type_min(T) (T)(is_signed_type(T) ? (T)1 << (8*sizeof(T)-1) : 0)
|
||||
* #define type_max(T) (T)(is_signed_type(T) ? ((T)1 << (8*sizeof(T)-1)) - 1 : ~(T)0)
|
||||
*
|
||||
* Unfortunately, the middle expressions, strictly speaking, have
|
||||
* undefined behaviour, and at least some versions of gcc warn about
|
||||
* the type_max expression (but not if -fsanitize=undefined is in
|
||||
* effect; in that case, the warning is deferred to runtime...).
|
||||
*
|
||||
* The slightly excessive casting in type_min is to make sure the
|
||||
* macros also produce sensible values for the exotic type _Bool. [The
|
||||
* overflow checkers only almost work for _Bool, but that's
|
||||
* a-feature-not-a-bug, since people shouldn't be doing arithmetic on
|
||||
* _Bools. Besides, the gcc builtins don't allow _Bool* as third
|
||||
* argument.]
|
||||
*
|
||||
* Idea stolen from
|
||||
* https://mail-index.netbsd.org/tech-misc/2007/02/05/0000.html -
|
||||
* credit to Christian Biere.
|
||||
*/
|
||||
#define is_signed_type(type) (((type)(-1)) < (type)1)
|
||||
#define __type_half_max(type) ((type)1 << (8*sizeof(type) - 1 - is_signed_type(type)))
|
||||
#define type_max(T) ((T)((__type_half_max(T) - 1) + __type_half_max(T)))
|
||||
#define type_min(T) ((T)((T)-type_max(T)-(T)1))
|
||||
|
||||
|
||||
#ifdef COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW
|
||||
/*
|
||||
* For simplicity and code hygiene, the fallback code below insists on
|
||||
* a, b and *d having the same type (similar to the min() and max()
|
||||
* macros), whereas gcc's type-generic overflow checkers accept
|
||||
* different types. Hence we don't just make check_add_overflow an
|
||||
* alias for __builtin_add_overflow, but add type checks similar to
|
||||
* below.
|
||||
*/
|
||||
#define check_add_overflow(a, b, d) ({ \
|
||||
typeof(a) __a = (a); \
|
||||
typeof(b) __b = (b); \
|
||||
typeof(d) __d = (d); \
|
||||
(void) (&__a == &__b); \
|
||||
(void) (&__a == __d); \
|
||||
__builtin_add_overflow(__a, __b, __d); \
|
||||
})
|
||||
|
||||
#define check_sub_overflow(a, b, d) ({ \
|
||||
typeof(a) __a = (a); \
|
||||
typeof(b) __b = (b); \
|
||||
typeof(d) __d = (d); \
|
||||
(void) (&__a == &__b); \
|
||||
(void) (&__a == __d); \
|
||||
__builtin_sub_overflow(__a, __b, __d); \
|
||||
})
|
||||
|
||||
#define check_mul_overflow(a, b, d) ({ \
|
||||
typeof(a) __a = (a); \
|
||||
typeof(b) __b = (b); \
|
||||
typeof(d) __d = (d); \
|
||||
(void) (&__a == &__b); \
|
||||
(void) (&__a == __d); \
|
||||
__builtin_mul_overflow(__a, __b, __d); \
|
||||
})
|
||||
|
||||
#else
|
||||
|
||||
|
||||
/* Checking for unsigned overflow is relatively easy without causing UB. */
|
||||
#define __unsigned_add_overflow(a, b, d) ({ \
|
||||
typeof(a) __a = (a); \
|
||||
typeof(b) __b = (b); \
|
||||
typeof(d) __d = (d); \
|
||||
(void) (&__a == &__b); \
|
||||
(void) (&__a == __d); \
|
||||
*__d = __a + __b; \
|
||||
*__d < __a; \
|
||||
})
|
||||
#define __unsigned_sub_overflow(a, b, d) ({ \
|
||||
typeof(a) __a = (a); \
|
||||
typeof(b) __b = (b); \
|
||||
typeof(d) __d = (d); \
|
||||
(void) (&__a == &__b); \
|
||||
(void) (&__a == __d); \
|
||||
*__d = __a - __b; \
|
||||
__a < __b; \
|
||||
})
|
||||
/*
|
||||
* If one of a or b is a compile-time constant, this avoids a division.
|
||||
*/
|
||||
#define __unsigned_mul_overflow(a, b, d) ({ \
|
||||
typeof(a) __a = (a); \
|
||||
typeof(b) __b = (b); \
|
||||
typeof(d) __d = (d); \
|
||||
(void) (&__a == &__b); \
|
||||
(void) (&__a == __d); \
|
||||
*__d = __a * __b; \
|
||||
__builtin_constant_p(__b) ? \
|
||||
__b > 0 && __a > type_max(typeof(__a)) / __b : \
|
||||
__a > 0 && __b > type_max(typeof(__b)) / __a; \
|
||||
})
|
||||
|
||||
/*
|
||||
* For signed types, detecting overflow is much harder, especially if
|
||||
* we want to avoid UB. But the interface of these macros is such that
|
||||
* we must provide a result in *d, and in fact we must produce the
|
||||
* result promised by gcc's builtins, which is simply the possibly
|
||||
* wrapped-around value. Fortunately, we can just formally do the
|
||||
* operations in the widest relevant unsigned type (u64) and then
|
||||
* truncate the result - gcc is smart enough to generate the same code
|
||||
* with and without the (u64) casts.
|
||||
*/
|
||||
|
||||
/*
|
||||
* Adding two signed integers can overflow only if they have the same
|
||||
* sign, and overflow has happened iff the result has the opposite
|
||||
* sign.
|
||||
*/
|
||||
#define __signed_add_overflow(a, b, d) ({ \
|
||||
typeof(a) __a = (a); \
|
||||
typeof(b) __b = (b); \
|
||||
typeof(d) __d = (d); \
|
||||
(void) (&__a == &__b); \
|
||||
(void) (&__a == __d); \
|
||||
*__d = (u64)__a + (u64)__b; \
|
||||
(((~(__a ^ __b)) & (*__d ^ __a)) \
|
||||
& type_min(typeof(__a))) != 0; \
|
||||
})
|
||||
|
||||
/*
|
||||
* Subtraction is similar, except that overflow can now happen only
|
||||
* when the signs are opposite. In this case, overflow has happened if
|
||||
* the result has the opposite sign of a.
|
||||
*/
|
||||
#define __signed_sub_overflow(a, b, d) ({ \
|
||||
typeof(a) __a = (a); \
|
||||
typeof(b) __b = (b); \
|
||||
typeof(d) __d = (d); \
|
||||
(void) (&__a == &__b); \
|
||||
(void) (&__a == __d); \
|
||||
*__d = (u64)__a - (u64)__b; \
|
||||
((((__a ^ __b)) & (*__d ^ __a)) \
|
||||
& type_min(typeof(__a))) != 0; \
|
||||
})
|
||||
|
||||
/*
|
||||
* Signed multiplication is rather hard. gcc always follows C99, so
|
||||
* division is truncated towards 0. This means that we can write the
|
||||
* overflow check like this:
|
||||
*
|
||||
* (a > 0 && (b > MAX/a || b < MIN/a)) ||
|
||||
* (a < -1 && (b > MIN/a || b < MAX/a) ||
|
||||
* (a == -1 && b == MIN)
|
||||
*
|
||||
* The redundant casts of -1 are to silence an annoying -Wtype-limits
|
||||
* (included in -Wextra) warning: When the type is u8 or u16, the
|
||||
* __b_c_e in check_mul_overflow obviously selects
|
||||
* __unsigned_mul_overflow, but unfortunately gcc still parses this
|
||||
* code and warns about the limited range of __b.
|
||||
*/
|
||||
|
||||
#define __signed_mul_overflow(a, b, d) ({ \
|
||||
typeof(a) __a = (a); \
|
||||
typeof(b) __b = (b); \
|
||||
typeof(d) __d = (d); \
|
||||
typeof(a) __tmax = type_max(typeof(a)); \
|
||||
typeof(a) __tmin = type_min(typeof(a)); \
|
||||
(void) (&__a == &__b); \
|
||||
(void) (&__a == __d); \
|
||||
*__d = (u64)__a * (u64)__b; \
|
||||
(__b > 0 && (__a > __tmax/__b || __a < __tmin/__b)) || \
|
||||
(__b < (typeof(__b))-1 && (__a > __tmin/__b || __a < __tmax/__b)) || \
|
||||
(__b == (typeof(__b))-1 && __a == __tmin); \
|
||||
})
|
||||
|
||||
|
||||
#define check_add_overflow(a, b, d) \
|
||||
__builtin_choose_expr(is_signed_type(typeof(a)), \
|
||||
__signed_add_overflow(a, b, d), \
|
||||
__unsigned_add_overflow(a, b, d))
|
||||
|
||||
#define check_sub_overflow(a, b, d) \
|
||||
__builtin_choose_expr(is_signed_type(typeof(a)), \
|
||||
__signed_sub_overflow(a, b, d), \
|
||||
__unsigned_sub_overflow(a, b, d))
|
||||
|
||||
#define check_mul_overflow(a, b, d) \
|
||||
__builtin_choose_expr(is_signed_type(typeof(a)), \
|
||||
__signed_mul_overflow(a, b, d), \
|
||||
__unsigned_mul_overflow(a, b, d))
|
||||
|
||||
|
||||
#endif /* COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW */
|
||||
|
||||
/**
|
||||
* array_size() - Calculate size of 2-dimensional array.
|
||||
*
|
||||
* @a: dimension one
|
||||
* @b: dimension two
|
||||
*
|
||||
* Calculates size of 2-dimensional array: @a * @b.
|
||||
*
|
||||
* Returns: number of bytes needed to represent the array or SIZE_MAX on
|
||||
* overflow.
|
||||
*/
|
||||
static inline __must_check size_t array_size(size_t a, size_t b)
|
||||
{
|
||||
size_t bytes;
|
||||
|
||||
if (check_mul_overflow(a, b, &bytes))
|
||||
return SIZE_MAX;
|
||||
|
||||
return bytes;
|
||||
}
|
||||
|
||||
/**
|
||||
* array3_size() - Calculate size of 3-dimensional array.
|
||||
*
|
||||
* @a: dimension one
|
||||
* @b: dimension two
|
||||
* @c: dimension three
|
||||
*
|
||||
* Calculates size of 3-dimensional array: @a * @b * @c.
|
||||
*
|
||||
* Returns: number of bytes needed to represent the array or SIZE_MAX on
|
||||
* overflow.
|
||||
*/
|
||||
static inline __must_check size_t array3_size(size_t a, size_t b, size_t c)
|
||||
{
|
||||
size_t bytes;
|
||||
|
||||
if (check_mul_overflow(a, b, &bytes))
|
||||
return SIZE_MAX;
|
||||
if (check_mul_overflow(bytes, c, &bytes))
|
||||
return SIZE_MAX;
|
||||
|
||||
return bytes;
|
||||
}
|
||||
|
||||
static inline __must_check size_t __ab_c_size(size_t n, size_t size, size_t c)
|
||||
{
|
||||
size_t bytes;
|
||||
|
||||
if (check_mul_overflow(n, size, &bytes))
|
||||
return SIZE_MAX;
|
||||
if (check_add_overflow(bytes, c, &bytes))
|
||||
return SIZE_MAX;
|
||||
|
||||
return bytes;
|
||||
}
|
||||
|
||||
/**
|
||||
* struct_size() - Calculate size of structure with trailing array.
|
||||
* @p: Pointer to the structure.
|
||||
* @member: Name of the array member.
|
||||
* @n: Number of elements in the array.
|
||||
*
|
||||
* Calculates size of memory needed for structure @p followed by an
|
||||
* array of @n @member elements.
|
||||
*
|
||||
* Return: number of bytes needed or SIZE_MAX on overflow.
|
||||
*/
|
||||
#define struct_size(p, member, n) \
|
||||
__ab_c_size(n, \
|
||||
sizeof(*(p)->member) + __must_be_array((p)->member),\
|
||||
sizeof(*(p)))
|
||||
|
||||
#endif /* __LINUX_OVERFLOW_H */
|
||||
|
|
@ -0,0 +1,20 @@
|
|||
// SPDX-License-Identifier: GPL-2.0+
|
||||
/* Copyright (C) 2018 Netronome Systems, Inc. */
|
||||
|
||||
#ifndef __TOOLS_LIBC_COMPAT_H
|
||||
#define __TOOLS_LIBC_COMPAT_H
|
||||
|
||||
#include <stdlib.h>
|
||||
#include <linux/overflow.h>
|
||||
|
||||
#ifdef COMPAT_NEED_REALLOCARRAY
|
||||
static inline void *reallocarray(void *ptr, size_t nmemb, size_t size)
|
||||
{
|
||||
size_t bytes;
|
||||
|
||||
if (unlikely(check_mul_overflow(nmemb, size, &bytes)))
|
||||
return NULL;
|
||||
return realloc(ptr, bytes);
|
||||
}
|
||||
#endif
|
||||
#endif
|
||||
|
|
@ -66,7 +66,7 @@ ifndef VERBOSE
|
|||
endif
|
||||
|
||||
FEATURE_USER = .libbpf
|
||||
FEATURE_TESTS = libelf libelf-getphdrnum libelf-mmap bpf
|
||||
FEATURE_TESTS = libelf libelf-getphdrnum libelf-mmap bpf reallocarray
|
||||
FEATURE_DISPLAY = libelf bpf
|
||||
|
||||
INCLUDES = -I. -I$(srctree)/tools/include -I$(srctree)/tools/arch/$(ARCH)/include/uapi -I$(srctree)/tools/include/uapi -I$(srctree)/tools/perf
|
||||
|
|
@ -120,6 +120,10 @@ ifeq ($(feature-libelf-getphdrnum), 1)
|
|||
override CFLAGS += -DHAVE_ELF_GETPHDRNUM_SUPPORT
|
||||
endif
|
||||
|
||||
ifeq ($(feature-reallocarray), 0)
|
||||
override CFLAGS += -DCOMPAT_NEED_REALLOCARRAY
|
||||
endif
|
||||
|
||||
# Append required CFLAGS
|
||||
override CFLAGS += $(EXTRA_WARNINGS)
|
||||
override CFLAGS += -Werror -Wall
|
||||
|
|
|
|||
|
|
@ -22,6 +22,7 @@
|
|||
* License along with this program; if not, see <http://www.gnu.org/licenses>
|
||||
*/
|
||||
|
||||
#define _GNU_SOURCE
|
||||
#include <stdlib.h>
|
||||
#include <stdio.h>
|
||||
#include <stdarg.h>
|
||||
|
|
@ -41,6 +42,7 @@
|
|||
#include <sys/stat.h>
|
||||
#include <sys/types.h>
|
||||
#include <sys/vfs.h>
|
||||
#include <tools/libc_compat.h>
|
||||
#include <libelf.h>
|
||||
#include <gelf.h>
|
||||
|
||||
|
|
@ -321,7 +323,7 @@ bpf_object__add_program(struct bpf_object *obj, void *data, size_t size,
|
|||
progs = obj->programs;
|
||||
nr_progs = obj->nr_programs;
|
||||
|
||||
progs = realloc(progs, sizeof(progs[0]) * (nr_progs + 1));
|
||||
progs = reallocarray(progs, nr_progs + 1, sizeof(progs[0]));
|
||||
if (!progs) {
|
||||
/*
|
||||
* In this case the original obj->programs
|
||||
|
|
@ -822,8 +824,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
|
|||
continue;
|
||||
}
|
||||
|
||||
reloc = realloc(reloc,
|
||||
sizeof(*obj->efile.reloc) * nr_reloc);
|
||||
reloc = reallocarray(reloc, nr_reloc,
|
||||
sizeof(*obj->efile.reloc));
|
||||
if (!reloc) {
|
||||
pr_warning("realloc failed\n");
|
||||
err = -ENOMEM;
|
||||
|
|
@ -1115,7 +1117,7 @@ bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
|
|||
return -LIBBPF_ERRNO__RELOC;
|
||||
}
|
||||
new_cnt = prog->insns_cnt + text->insns_cnt;
|
||||
new_insn = realloc(prog->insns, new_cnt * sizeof(*insn));
|
||||
new_insn = reallocarray(prog->insns, new_cnt, sizeof(*insn));
|
||||
if (!new_insn) {
|
||||
pr_warning("oom in prog realloc\n");
|
||||
return -ENOMEM;
|
||||
|
|
|
|||
Loading…
Reference in New Issue