user-level: 0.813
graphic: 0.758
KVM: 0.730
TCG: 0.726
x86: 0.714
register: 0.710
performance: 0.705
semantic: 0.690
i386: 0.686
device: 0.686
ppc: 0.685
arm: 0.683
mistranslation: 0.681
permissions: 0.675
debug: 0.672
vnc: 0.667
architecture: 0.667
virtual: 0.654
VMM: 0.652
PID: 0.636
peripherals: 0.634
assembly: 0.627
hypervisor: 0.614
socket: 0.602
network: 0.599
kernel: 0.594
risc-v: 0.582
boot: 0.568
files: 0.515
--------------------
x86: 0.990
user-level: 0.896
debug: 0.745
TCG: 0.528
virtual: 0.091
files: 0.079
performance: 0.072
PID: 0.053
register: 0.029
assembly: 0.026
kernel: 0.021
hypervisor: 0.018
semantic: 0.009
architecture: 0.008
device: 0.007
ppc: 0.005
network: 0.004
risc-v: 0.004
socket: 0.003
VMM: 0.002
graphic: 0.002
permissions: 0.002
boot: 0.002
peripherals: 0.002
vnc: 0.001
KVM: 0.001
mistranslation: 0.001
arm: 0.000
i386: 0.000

qemu-x86_64 crashes when the application calls pthread_getattr_np()
Description of problem:
QEMU user emulation crashes with this program:
```
#define _GNU_SOURCE
#include <stdio.h>
#include <pthread.h>

int main()
{
        pthread_attr_t attr;
        int error = pthread_getattr_np(pthread_self(), &attr);

        printf("%d\n", error);
        return 0;
}
```
Steps to reproduce:
1. Compile the program above
2. Run QEMU
Additional information:
QEMU crashes with:
```
qemu-x86_64: QEMU internal SIGSEGV {code=MAPERR, addr=0x20}
Segmentation fault (core dumped)

```

In gdb I get this backtrace:
```
#0  0x0000555555627d6d in open_self_maps_2 (opaque=0x7fffffffc020, guest_start=18446744073699065856, guest_end=<optimized out>, flags=12) at ../linux-user/syscall.c:8089
#1  0x000055555560ce67 in walk_memory_regions (priv=priv@entry=0x7fffffffc020, fn=fn@entry=0x555555627d30 <open_self_maps_2>) at ../accel/tcg/user-exec.c:176
#2  0x0000555555628b3a in open_self_maps_1 (smaps=<optimized out>, fd=<optimized out>, env=<optimized out>) at ../linux-user/syscall.c:8112
#3  open_self_maps (cpu_env=<optimized out>, fd=3) at ../linux-user/syscall.c:8122
#4  0x0000555555631e24 in do_guest_openat (cpu_env=cpu_env@entry=0x55555583ae20, dirfd=dirfd@entry=-100, fname=fname@entry=0x2aaaab496eb4 "/proc/self/maps", flags=524288, mode=mode@entry=0, safe=safe@entry=true) at ../linux-user/syscall.c:8381
#5  0x0000555555638f71 in do_syscall1 (cpu_env=cpu_env@entry=0x55555583ae20, num=num@entry=257, arg1=arg1@entry=4294967196, arg2=arg2@entry=46912506523316, arg3=arg3@entry=524288, arg4=arg4@entry=0, arg5=<optimized out>, arg6=<optimized out>, arg8=0, arg7=0) at ../linux-user/syscall.c:9075
#6  0x000055555563b659 in do_syscall (cpu_env=cpu_env@entry=0x55555583ae20, num=257, arg1=4294967196, arg2=46912506523316, arg3=524288, arg4=0, arg5=8, arg6=1, arg7=0, arg8=0) at ../linux-user/syscall.c:13658
#7  0x000055555558db19 in cpu_loop (env=env@entry=0x55555583ae20) at ../linux-user/x86_64/../i386/cpu_loop.c:242
#8  0x00005555555898d8 in main (argc=<optimized out>, argv=0x7fffffffdd38, envp=<optimized out>) at ../linux-user/main.c:1012

```

This bug was introduced in the rewrite of `open_self_maps` in 7b7a3366e142d3baeb3fd1d3660a50e7956c19eb.
The current master (5767815218efd3cbfd409505ed824d5f356044ae) is still affected.