8dedb0dc96
* mem.c (sys_mmap): Ensure unsigned expansion of tcp->u_arg[5]. Add page shift of offset for I386. Use tcp->ext_arg[5] as offset for X32. (sys_old_mmap): [X32] Remove this function, X32 doesn't use is. Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
50 lines
1.3 KiB
C
50 lines
1.3 KiB
C
// Test program which explores whether mmap's ofs parameter
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// is 64-bit, and whether it needs to be shifted << PAGE_SHIFT.
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// Apparently it is 64-bit and isn't shifted.
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//
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// Build: x86_64-gcc -static -Wall -ox32_mmap x32_mmap.c
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// Typical output:
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// 7f9390696000-7f93906a6000 r--s 12345670000 08:06 2224545 /etc/passwd
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// ^^^^^^^^^^^
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#define _GNU_SOURCE
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#include <sys/types.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <errno.h>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <sys/syscall.h>
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// Ensure we are compiling to 64 bits
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struct bug { int t[sizeof(long) > 4 ? 1 : -1]; };
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int main(int argc, char **argv)
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{
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long ofs = 0x12345670000; // fails if not page-aligned
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errno = 0;
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close(0);
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if (open("/etc/passwd", O_RDONLY))
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return 1;
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long r = syscall(
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(long) (__NR_mmap | 0x40000000), // make x32 call
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(long) (0), // start
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(long) (0x10000), // len
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(long) (PROT_READ), // prot
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(long) (MAP_SHARED), // flags
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(long) (0), // fd
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(long) (ofs) // ofs
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);
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printf("ret:0x%lx errno:%m\n", r);
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char buf[16*1024];
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sprintf(buf, "/proc/%d/maps", getpid());
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int fd = open(buf, O_RDONLY);
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if (fd > 0) {
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int sz = read(fd, buf, sizeof(buf));
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if (sz > 0)
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write(1, buf, sz);
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}
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return 0;
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}
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