Re: [PATCH] gas/config/tc-score7.c: Use symbol_get_frag() instead of direct reference to fix segment fault issue

[Chen Gang <gang dot chen dot 5i5j at gmail dot com>]

Hello Maintainers:

Is it patch OK? please help check when you have free time, thanks.

Originally, I could not find the related Changelog for 'gas', so I did
not mark change log for it.

BTW: After fix this issue, binutiles and gcc can generated score-elf-*
to compile Linux upstream kernel. And now it can compile Linux upstream
kernel successfully! :-)

Thanks.

On 06/08/2014 12:56 PM, Chen Gang wrote:
> If 'symbol' is 'local_symbol' and already local_symbol_converted_p(),
> caller has to use symbol_get_frag() instead of direct reference to get
> 'frag', or may use invalid pointer to cause segment fault.
> 
> The related assembly file for score is below, and related statement is
> "beq   .L10".
> 
> 	.file	"conftest.c"
> 	.text
> 	.align	2
> 	.globl	foo
> .LFB0:
> 	.ent	foo
> foo:
> 	.frame	r2,24,r3, 0		# vars= 4, regs= 4, args= 4, gp= 0
> 	.mask	0x0000300c,-4
> 	sw	r13, [r0,-4]+
> .LCFI0:
> 	sw	r12, [r0,-4]+
> .LCFI1:
> 	sw	r3, [r0,-4]+
> .LCFI2:
> 	sw	r2, [r0,-4]+
> .LCFI3:
> 	addi	r0, -8
> .LCFI4:
> 	mv!	r2, r0
> .LCFI5:
> .LEHB0:
> 	jl	bar
> .LEHE0:
> 	ldiu!	r12, 1
> .L5:
> 	addri	r6, r2, 4
> 	mv!	r4, r6
> .LEHB1:
> 	jl	clean
> 	cmpi.c  r12, 1
> 	beq    .L10
> 	j	.L9
> .L6:
> 	mv!	r13, r4
> 	ldiu!	r12, 0
> 	j	.L5
> .L9:
> 	mv!	r6, r13
> 	mv!	r4, r6
> 	jl	_Unwind_Resume
> .LEHE1:
> .L10:
> 	#nop!
> 	addi	r2, 8
> 	mv!	r0, r2
> 	lw	r2, [r0]+, 4
> 	lw	r3, [r0]+, 4
> 	lw	r12, [r0]+, 4
> 	lw	r13, [r0]+, 4
> 	br!	r3
> 	.end	foo
> .LFE0:
> 	.globl	__gcc_personality_v0
> 	.section	.gcc_except_table,"aw",@progbits
> .LLSDA0:
> 	.byte	0xff
> 	.byte	0xff
> 	.byte	0x3
> 	.byte	0x1a
> 	.4byte	.LEHB0-.LFB0
> 	.4byte	.LEHE0-.LEHB0
> 	.4byte	.L6-.LFB0
> 	.byte	0
> 	.4byte	.LEHB1-.LFB0
> 	.4byte	.LEHE1-.LEHB1
> 	.4byte	0
> 	.byte	0
> 	.text
> 	.size	foo, .-foo
> 	.section	.eh_frame,"aw",@progbits
> .Lframe1:
> 	.4byte	.LECIE1-.LSCIE1
> .LSCIE1:
> 	.4byte	0
> 	.byte	0x3
> 	.string	"zPL"
> 	.byte	0x1
> 	.byte	0x7c
> 	.byte	0x3
> 	.byte	0x6
> 	.byte	0
> 	.4byte	__gcc_personality_v0
> 	.byte	0
> 	.byte	0xc
> 	.byte	0
> 	.byte	0
> 	.align	2
> .LECIE1:
> .LSFDE1:
> 	.4byte	.LEFDE1-.LASFDE1
> .LASFDE1:
> 	.4byte	.LASFDE1-.Lframe1
> 	.4byte	.LFB0
> 	.4byte	.LFE0-.LFB0
> 	.byte	0x4
> 	.4byte	.LLSDA0
> 	.byte	0x4
> 	.4byte	.LCFI0-.LFB0
> 	.byte	0xe
> 	.byte	0x4
> 	.byte	0x8d
> 	.byte	0x1
> 	.byte	0x4
> 	.4byte	.LCFI1-.LCFI0
> 	.byte	0xe
> 	.byte	0x8
> 	.byte	0x8c
> 	.byte	0x2
> 	.byte	0x4
> 	.4byte	.LCFI2-.LCFI1
> 	.byte	0xe
> 	.byte	0xc
> 	.byte	0x83
> 	.byte	0x3
> 	.byte	0x4
> 	.4byte	.LCFI3-.LCFI2
> 	.byte	0xe
> 	.byte	0x10
> 	.byte	0x82
> 	.byte	0x4
> 	.byte	0x4
> 	.4byte	.LCFI4-.LCFI3
> 	.byte	0xe
> 	.byte	0x18
> 	.byte	0x4
> 	.4byte	.LCFI5-.LCFI4
> 	.byte	0xd
> 	.byte	0x2
> 	.align	2
> .LEFDE1:
> 	.ident	"GCC: (GNU) 4.10.0 20140530 (experimental)"
> 
> 
> Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
> ---
>  gas/config/tc-score7.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/gas/config/tc-score7.c b/gas/config/tc-score7.c
> index 0a0db2d..8b4206d 100644
> --- a/gas/config/tc-score7.c
> +++ b/gas/config/tc-score7.c
> @@ -5264,7 +5264,7 @@ s7_b32_relax_to_b16 (fragS * fragp)
>    else
>      {
>        if (s->bsym != 0)
> -	symbol_address = (addressT) s->sy_frag->fr_address;
> +	symbol_address = (addressT) symbol_get_frag(s)->fr_address;
>      }
>  
>    value = s7_md_chars_to_number (fragp->fr_literal, s7_INSN_SIZE);
> 

-- 
Chen Gang

Open, share, and attitude like air, water, and life which God blessed