[Qemu-devel] [PATCH] Revert "Use the host exit syscall for exiting (Lauro Ramos Venancio)."

[Qemu-devel] [PATCH] Revert "Use the host exit syscall for exiting (Lauro Ramos Venancio)."

[Felipe Contreras]

This breaks pthread_join on arm-linux-user.

---
 linux-user/syscall.c |    4 +---
 1 files changed, 1 insertions(+), 3 deletions(-)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 40eab4e..572fa0a 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -156,7 +156,6 @@ static type name (type1 arg1,type2 arg2,type3 arg3,type4 arg4,type5 arg5,	\
 }
 
 
-#define __NR_sys_exit __NR_exit
 #define __NR_sys_uname __NR_uname
 #define __NR_sys_faccessat __NR_faccessat
 #define __NR_sys_fchmodat __NR_fchmodat
@@ -198,7 +197,6 @@ static int gettid(void) {
     return -ENOSYS;
 }
 #endif
-_syscall1(int,sys_exit,int,status)
 _syscall1(int,sys_uname,struct new_utsname *,buf)
 #if defined(TARGET_NR_faccessat) && defined(__NR_faccessat)
 _syscall4(int,sys_faccessat,int,dirfd,const char *,pathname,int,mode,int,flags)
@@ -3433,7 +3431,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
 #endif
         gdb_exit(cpu_env, arg1);
         /* XXX: should free thread stack and CPU env */
-        sys_exit(arg1);
+        _exit(arg1);
         ret = 0; /* avoid warning */
         break;
     case TARGET_NR_read:
-- 
1.6.2

Re: [Qemu-devel] [PATCH] Revert "Use the host exit syscall for exiting (Lauro Ramos Venancio)."

[Laurent Desnogues]

On Sat, Mar 7, 2009 at 1:20 PM, Felipe Contreras
<felipe.contreras@gmail.com> wrote:
> This breaks pthread_join on arm-linux-user.

I am not sure the fix is correct.  If you run tests/testthread.c you'll
notice the thread2 doesn't print the 20 values it should.

BTW it looks like this test doesn't run on i386 and x86_64:  it
ends immediately.


Laurent

> ---
>  linux-user/syscall.c |    4 +---
>  1 files changed, 1 insertions(+), 3 deletions(-)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 40eab4e..572fa0a 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -156,7 +156,6 @@ static type name (type1 arg1,type2 arg2,type3 arg3,type4 arg4,type5 arg5,   \
>  }
>
>
> -#define __NR_sys_exit __NR_exit
>  #define __NR_sys_uname __NR_uname
>  #define __NR_sys_faccessat __NR_faccessat
>  #define __NR_sys_fchmodat __NR_fchmodat
> @@ -198,7 +197,6 @@ static int gettid(void) {
>     return -ENOSYS;
>  }
>  #endif
> -_syscall1(int,sys_exit,int,status)
>  _syscall1(int,sys_uname,struct new_utsname *,buf)
>  #if defined(TARGET_NR_faccessat) && defined(__NR_faccessat)
>  _syscall4(int,sys_faccessat,int,dirfd,const char *,pathname,int,mode,int,flags)
> @@ -3433,7 +3431,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
>  #endif
>         gdb_exit(cpu_env, arg1);
>         /* XXX: should free thread stack and CPU env */
> -        sys_exit(arg1);
> +        _exit(arg1);
>         ret = 0; /* avoid warning */
>         break;
>     case TARGET_NR_read:
> --
> 1.6.2
>
>
>
>

Re: [Qemu-devel] [PATCH] Revert "Use the host exit syscall for exiting (Lauro Ramos Venancio)."

[Paul Brook]

On Saturday 07 March 2009, Felipe Contreras wrote:
> This breaks pthread_join on arm-linux-user.
>..
>          /* XXX: should free thread stack and CPU env */
> -        sys_exit(arg1);
> +        _exit(arg1);

No. You're just reverting an earlier (also incorrect) change.

Paul

Re: [Qemu-devel] [PATCH] Revert "Use the host exit syscall for exiting (Lauro Ramos Venancio)."

[Felipe Contreras]

On Sat, Mar 7, 2009 at 4:05 PM, Paul Brook <paul@codesourcery.com> wrote:
> On Saturday 07 March 2009, Felipe Contreras wrote:
>> This breaks pthread_join on arm-linux-user.
>>..
>>          /* XXX: should free thread stack and CPU env */
>> -        sys_exit(arg1);
>> +        _exit(arg1);
>
> No. You're just reverting an earlier (also incorrect) change.

That commit introduced a regression arm-linux-user, I'm just reverting
the change.

What do you propose? Leaving arm-linux-user broken is not good.

-- 
Felipe Contreras

Re: [Qemu-devel] [PATCH] Revert "Use the host exit syscall for exiting (Lauro Ramos Venancio)."

[Paul Brook]

On Saturday 07 March 2009, Felipe Contreras wrote:
> On Sat, Mar 7, 2009 at 4:05 PM, Paul Brook <paul@codesourcery.com> wrote:
> > On Saturday 07 March 2009, Felipe Contreras wrote:
> >> This breaks pthread_join on arm-linux-user.
> >>..
> >>          /* XXX: should free thread stack and CPU env */
> >> -        sys_exit(arg1);
> >> +        _exit(arg1);
> >
> > No. You're just reverting an earlier (also incorrect) change.
>
> That commit introduced a regression arm-linux-user, I'm just reverting
> the change.
>
> What do you propose? Leaving arm-linux-user broken is not good.

It's broken both after your patch, you're just exchanging one bit of 
brokenness for another. The solution is to fix it properly, like I already 
did.

Paul

Re: [Qemu-devel] [PATCH] Revert "Use the host exit syscall for exiting (Lauro Ramos Venancio)."

[Felipe Contreras]

On Sat, Mar 7, 2009 at 6:08 PM, Paul Brook <paul@codesourcery.com> wrote:
> On Saturday 07 March 2009, Felipe Contreras wrote:
>> On Sat, Mar 7, 2009 at 4:05 PM, Paul Brook <paul@codesourcery.com> wrote:
>> > On Saturday 07 March 2009, Felipe Contreras wrote:
>> >> This breaks pthread_join on arm-linux-user.
>> >>..
>> >>          /* XXX: should free thread stack and CPU env */
>> >> -        sys_exit(arg1);
>> >> +        _exit(arg1);
>> >
>> > No. You're just reverting an earlier (also incorrect) change.
>>
>> That commit introduced a regression arm-linux-user, I'm just reverting
>> the change.
>>
>> What do you propose? Leaving arm-linux-user broken is not good.
>
> It's broken both after your patch, you're just exchanging one bit of
> brokenness for another. The solution is to fix it properly, like I already
> did.

Cool, I confirm your patch also fixes the issue.

Thanks.

-- 
Felipe Contreras

Re: [Qemu-devel] [PATCH] Revert "Use the host exit syscall for exiting (Lauro Ramos Venancio)."

[Laurent Desnogues]

On Sat, Mar 7, 2009 at 5:02 PM, Felipe Contreras
<felipe.contreras@gmail.com> wrote:
> On Sat, Mar 7, 2009 at 4:05 PM, Paul Brook <paul@codesourcery.com> wrote:
[...]
>> No. You're just reverting an earlier (also incorrect) change.
>
> That commit introduced a regression arm-linux-user, I'm just reverting
> the change.
>
> What do you propose? Leaving arm-linux-user broken is not good.

Paul's commit 6735 fixes at least testthread for ARM (though it doesn't
fix it from i386 and x86_64).


Laurent

Re: [Qemu-devel] [PATCH] Revert "Use the host exit syscall for exiting (Lauro Ramos Venancio)."

[Paul Brook]

> >> No. You're just reverting an earlier (also incorrect) change.
> >
> > That commit introduced a regression arm-linux-user, I'm just reverting
> > the change.
> >
> > What do you propose? Leaving arm-linux-user broken is not good.
>
> Paul's commit 6735 fixes at least testthread for ARM (though it doesn't
> fix it from i386 and x86_64).

That's because x86/x86-64 doesn't support threads/NPTL at all.

Paul