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Print the first argument of memfd_create syscall as a path

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The limit imposed by the kernel on the length of memfd_create first
argument is NAME_MAX - strlen("memfd:").

* memfd_create.c (SYS_FUNC(memfd_create)): Print the first argument
using printpathn.
* tests/memfd_create.c: Check it.
This commit is contained in:
Дмитрий Левин 2017-11-18 00:19:31 +00:00
parent 596662a61d
commit c75392f67a
2 changed files with 51 additions and 6 deletions
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2
memfd_create.c
View File

@ -32,7 +32,7 @@
SYS_FUNC(memfd_create)
{
printstr(tcp, tcp->u_arg[0]);
printpathn(tcp, tcp->u_arg[0], 255 - (sizeof("memfd:") - 1));
tprints(", ");
printflags(memfd_create_flags, tcp->u_arg[1], "MFD_???");

55
tests/memfd_create.c
View File

@ -1,3 +1,32 @@
/*
* Check decoding of memfd_create syscall.
*
* Copyright (c) 2015-2017 Dmitry V. Levin <ldv@altlinux.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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 "tests.h"
#include <asm/unistd.h>
#include "scno.h"
@ -5,17 +34,33 @@
#ifdef __NR_memfd_create
# include <stdio.h>
# include <stdint.h>
# include <unistd.h>
static const char *errstr;
static long
k_memfd_create(const kernel_ulong_t name, const kernel_ulong_t flags)
{
const long rc = syscall(__NR_memfd_create, name, flags);
errstr = sprintrc(rc);
return rc;
}
int
main(void)
{
static const char text[] = "strace";
int rc = syscall(__NR_memfd_create, text, 0xf);
const size_t size = 255 - (sizeof("memfd:") - 1) + 1;
char *const pattern = tail_alloc(size);
fill_memory_ex(pattern, size, '0', 10);
printf("memfd_create(\"%s\", %s) = %s\n",
text, "MFD_CLOEXEC|MFD_ALLOW_SEALING|MFD_HUGETLB|0x8",
sprintrc(rc));
const kernel_ulong_t flags = (kernel_ulong_t) 0xfacefeed0000000fULL;
k_memfd_create((uintptr_t) pattern, flags);
printf("memfd_create(\"%.*s\"..., %s) = %s\n",
(int) size - 1, pattern,
"MFD_CLOEXEC|MFD_ALLOW_SEALING|MFD_HUGETLB|0x8",
errstr);
puts("+++ exited with 0 +++");
return 0;