[v3,6/9] aarch64: Use tpidr_el0 rather than __errno_location in librt

  From: Richard Henderson <rth@redhat.com>

---
 sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data |  1 -
 sysdeps/unix/sysv/linux/aarch64/sysdep.h           | 19 +++++--------------
 2 files changed, 5 insertions(+), 15 deletions(-)
  

On 25 May 2014 20:41, Richard Henderson <rth@twiddle.net> wrote:
> From: Richard Henderson <rth@redhat.com>
>
> ---
>  sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data |  1 -
>  sysdeps/unix/sysv/linux/aarch64/sysdep.h           | 19 +++++--------------
>  2 files changed, 5 insertions(+), 15 deletions(-)
>

This looks ok. /Marcus
  

On 2014/5/26 3:41, Richard Henderson wrote:
> From: Richard Henderson <rth@redhat.com>
> 
> ---
>  sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data |  1 -
>  sysdeps/unix/sysv/linux/aarch64/sysdep.h           | 19 +++++--------------
>  2 files changed, 5 insertions(+), 15 deletions(-)
> 
> diff --git a/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data b/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data
> index 84af95d..dfca9a7 100644
> --- a/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data
> +++ b/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data
> @@ -12,4 +12,3 @@ libm.so: matherr
>  libm.so: __signbit
>  libm.so: __signbitf
>  libm.so: __signbitl
> -libpthread.so: __errno_location
> diff --git a/sysdeps/unix/sysv/linux/aarch64/sysdep.h b/sysdeps/unix/sysv/linux/aarch64/sysdep.h
> index 0e91f83..8cce986 100644
> --- a/sysdeps/unix/sysv/linux/aarch64/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/aarch64/sysdep.h
> @@ -123,21 +123,12 @@
>  
>  #   define SYSCALL_ERROR_HANDLER				\
>  .Lsyscall_error:						\
> -	stp     x29, x30, [sp, -32]!;				\
> -	cfi_adjust_cfa_offset (32);				\
> -	cfi_rel_offset (x29, 0);				\
> -	cfi_rel_offset (x30, 8);				\
> -        add     x29, sp, 0;					\
> -        str     x19, [sp,16];					\
> -	neg	x19, x0;					\
> -	bl	C_SYMBOL_NAME(__errno_location);		\
> -	str	w19, [x0];					\
> +	adrp	x1, :gottprel:errno;				\
> +	neg	w2, w0;						\
> +	ldr	x1, [x1, :gottprel_lo12:errno];			\
> +	mrs	x3, tpidr_el0;					\
>  	mov	x0, -1;						\
> -        ldr     x19, [sp,16];					\
> -        ldp     x29, x30, [sp], 32;				\
> -	cfi_adjust_cfa_offset (-32);				\
> -	cfi_restore (x29);					\
> -	cfi_restore (x30);					\
> +	str	w2, [x1, x3];					\
>  	RET;
>  #  endif
>  # else
> 
Hi,

I met a Segmentation fault when I ran an ilp32 application on big-endian arm64 with this patch.

----------------cut here--------------------
mq_timedreceive[1041]: unhandled input address range fault (11) at 0xa00000f752f850, esr 0x92000044
pgd = ffffffc03ee92000
[a00000f752f850] *pgd=000000003ef17003, *pmd=0000000000000000

CPU: 2 PID: 1041 Comm: mq_timedreceive Not tainted 3.16.0+ #10
task: ffffffc03ec19ec0 ti: ffffffc03ef7c000 task.ti: ffffffc03ef7c000
PC is at 0xf6fdc668
LR is at 0x401fcc
pc : [<00000000f6fdc668>] lr : [<0000000000401fcc>] pstate: 20000000
sp : 00000000ffb3d130
x29: 00000000ffb3d130 x28: 0000000000000000 
x27: 0000000000405000 x26: 0000000000000003 
x25: 00000000004057a0 x24: 00000000ffb3f1d0 
x23: 000000000041c000 x22: 000000000041c000 
x21: 0000000000417798 x20: 00000000f703f860 
x19: 00000000ffb3d1d0 x18: 000000000ebf6480 
x17: 00000000f6fdc680 x16: 0000000000000000 
x15: 000c7fb76c000000 x14: 0000000000000000 
x13: 00000003e8000000 x12: 0000000000000018 
x11: 0000000000033320 x10: 00000000544d96a3 
x9 : 0000000000003d2e x8 : 00000000000000b7 
x7 : 0000000000000000 x6 : 00000000f7042000 
x5 : 00000000ffb3d1b8 x4 : 00000000ffb3d1c0 
x3 : 00000000f703f850 x2 : 000000000000005a 
x1 : 0fa00000004f0000 x0 : ffffffffffffffff 

Segmentation fault
---------------------------------------------

The register x1 got a bad value.

Do we have any patch to fix this ?


Regards,
Yang
  

ldr     x1, [x1, :gottprel_lo12:errno]; 
Needs to change to be:
ldr PTR_REG(1), [x1, :gottprel_lo12:errno]; 

Thanks,
Andrew Pinski
  

On 2014/11/12 11:45, Pinski, Andrew wrote:
> ldr     x1, [x1, :gottprel_lo12:errno]; 
> Needs to change to be:
> ldr PTR_REG(1), [x1, :gottprel_lo12:errno]; 
> 
> Thanks,
> Andrew Pinski
> ________________________________________
It works.

Thanks!