svn commit: r355045 - head/libexec/rtld-elf/powerpc

Konstantin Belousov kostikbel at gmail.com
Sun Nov 24 13:04:50 UTC 2019


On Sun, Nov 24, 2019 at 04:35:29AM +0000, Justin Hibbits wrote:
> Author: jhibbits
> Date: Sun Nov 24 04:35:29 2019
> New Revision: 355045
> URL: https://svnweb.freebsd.org/changeset/base/355045
> 
> Log:
>   rtld/powerpc: Fix _rtld_bind_start for powerpcspe
>   
>   Summary:
>   We need to save off the full 64-bit register, not just the low 32 bits,
>   of all registers getting saved off in _rtld_bind_start.  Additionally,
>   we need to save off the other SPE registers (SPEFSCR and accumulator),
>   so that their program state is not affected by the PLT resolver.
Why do you need to save these registers ?  Why would rtld touch them ?

>   
>   Reviewed by:	bdragon
>   Differential Revision:	https://reviews.freebsd.org/D22520
> 
> Modified:
>   head/libexec/rtld-elf/powerpc/rtld_start.S
> 
> Modified: head/libexec/rtld-elf/powerpc/rtld_start.S
> ==============================================================================
> --- head/libexec/rtld-elf/powerpc/rtld_start.S	Sun Nov 24 02:27:50 2019	(r355044)
> +++ head/libexec/rtld-elf/powerpc/rtld_start.S	Sun Nov 24 04:35:29 2019	(r355045)
> @@ -30,6 +30,7 @@
>   */
>  
>  #include <machine/asm.h>
> +#include <machine/spr.h>	/* For SPR_SPEFSCR if needed. */
>  
>  .extern _GLOBAL_OFFSET_TABLE_
>  .extern _DYNAMIC
> @@ -101,6 +102,20 @@ _ENTRY(.rtld_start)
>  	li      %r0,1		/* _exit() */
>  	sc
>  
> +#ifdef __SPE__
> +/* stack space for 30 GPRs + SPEFSCR/ACC/lr/cr */
> +#define	NREGS		31
> +#define	GPRWIDTH	8
> +#define	FUDGE		4	/* Fudge factor for alignment */
> +#else
> +/* stack space for 30 GPRs + lr/cr */
> +#define	NREGS		30
> +#define	GPRWIDTH	4
> +#define	FUDGE		0
> +#endif
> +/* Stack frame needs the 12-byte ABI frame plus fudge factor. */
> +#define	STACK_SIZE	(NREGS * GPRWIDTH + 4 * 2 + 12 + FUDGE)
> +
>  /*
>   * _rtld_bind_secureplt_start()
>   *
> @@ -110,8 +125,12 @@ _ENTRY(.rtld_start)
>   * So for bss-plt, we multiply the index by 12 to get the offset.
>   */
>  _ENTRY(_rtld_bind_secureplt_start)
> -	stwu    %r1,-160(%r1)		# stack space for 29 regs + r0/lr/cr
> +	stwu    %r1,-STACK_SIZE(%r1)
> +#ifdef __SPE__
> +	evstdd	%r0,24(%r1)
> +#else
>  	stw     %r0,20(%r1)		# save r0
> +#endif
>  
>  	/*
>  	 * Instead of division which is costly we will use multiplicative
> @@ -137,28 +156,113 @@ _ENTRY(_rtld_bind_secureplt_start)
>  	.globl  _rtld_bind
>  
>  _ENTRY(_rtld_bind_start)
> -	stwu    %r1,-160(%r1)		# stack space for 29 regs + r0/lr/cr
> +	stwu    %r1,-STACK_SIZE(%r1)
> +#ifdef __SPE__
> +	evstdd	%r0,24(%r1)
> +#else
>  	stw     %r0,20(%r1)		# save r0
> +#endif
>  1:
>  	mflr    %r0
>  	stw     %r0,16(%r1)		# save lr
>  	mfcr    %r0
>  	stw     %r0,12(%r1)		# save cr
> +#ifdef __SPE__
> +	evstdd	%r3, 32(%r1)
> +	evstdd	%r4, 40(%r1)
> +	evstdd	%r5, 48(%r1)
> +	evstdd	%r6, 56(%r1)
> +	evstdd	%r7, 64(%r1)
> +	evstdd	%r8, 72(%r1)
> +	evstdd	%r9, 80(%r1)
> +	evstdd	%r10, 88(%r1)
> +	evstdd	%r11, 96(%r1)
> +	evstdd	%r12, 104(%r1)
> +	evstdd	%r13, 112(%r1)
> +	evstdd	%r14, 120(%r1)
> +	evstdd	%r15, 128(%r1)
> +	evstdd	%r16, 136(%r1)
> +	evstdd	%r17, 144(%r1)
> +	evstdd	%r18, 152(%r1)
> +	evstdd	%r19, 160(%r1)
> +	evstdd	%r20, 168(%r1)
> +	evstdd	%r21, 176(%r1)
> +	evstdd	%r22, 184(%r1)
> +	evstdd	%r23, 192(%r1)
> +	evstdd	%r24, 200(%r1)
> +	evstdd	%r25, 208(%r1)
> +	evstdd	%r26, 216(%r1)
> +	evstdd	%r27, 224(%r1)
> +	evstdd	%r28, 232(%r1)
> +	evstdd	%r29, 240(%r1)
> +	evstdd	%r30, 248(%r1)
> +	li	%r3, 256
> +	evstddx	%r31, %r1, %r3
> +	evxor	%r0, %r0, %r0
> +	li	%r3, 264
> +	evmwumiaa	%r0, %r0, %r0
> +	evstddx	%r0, %r1, %r3
> +	mfspr	%r3, SPR_SPEFSCR
> +	stw	%r3, 20(%r1)
> +#else
>  	stmw    %r3,24(%r1)		# save r3-r31
> +#endif
>  
>  	mr      %r3,%r12		# obj
>  	mulli   %r4,%r11,12		# rela index * sizeof(Elf_Rela)
>  	bl      _rtld_bind		# target addr = _rtld_bind(obj, reloff)
>  	mtctr   %r3			# move absolute target addr into ctr
>  
> +#ifdef __SPE__
> +	lwz	%r3, 20(%r1)
> +	mtspr	SPR_SPEFSCR, %r3
> +	li	%r3, 264
> +	evlddx	%r0, %r3, %r1
> +	evmra	%r0, %r0
> +	evldd	%r3, 32(%r1)
> +	evldd	%r4, 40(%r1)
> +	evldd	%r5, 48(%r1)
> +	evldd	%r6, 56(%r1)
> +	evldd	%r7, 64(%r1)
> +	evldd	%r8, 72(%r1)
> +	evldd	%r9, 80(%r1)
> +	evldd	%r10, 88(%r1)
> +	evldd	%r11, 96(%r1)
> +	evldd	%r12, 104(%r1)
> +	evldd	%r13, 112(%r1)
> +	evldd	%r14, 120(%r1)
> +	evldd	%r15, 128(%r1)
> +	evldd	%r16, 136(%r1)
> +	evldd	%r17, 144(%r1)
> +	evldd	%r18, 152(%r1)
> +	evldd	%r19, 160(%r1)
> +	evldd	%r20, 168(%r1)
> +	evldd	%r21, 176(%r1)
> +	evldd	%r22, 184(%r1)
> +	evldd	%r23, 192(%r1)
> +	evldd	%r24, 200(%r1)
> +	evldd	%r25, 208(%r1)
> +	evldd	%r26, 216(%r1)
> +	evldd	%r27, 224(%r1)
> +	evldd	%r28, 232(%r1)
> +	evldd	%r29, 240(%r1)
> +	evldd	%r30, 248(%r1)
> +	li	%r0, 256
> +	evlddx	%r31, %r1, %r0
> +#else
>          lmw     %r3,24(%r1)		# restore r3-r31
> +#endif
>          lwz     %r0,12(%r1)		# restore cr
>          mtcr    %r0
>          lwz     %r0,16(%r1)		# restore lr
>          mtlr    %r0
> +#ifdef __SPE__
> +	evldd	%r0,24(%r1)
> +#else
>          lwz     %r0,20(%r1)		# restore r0
> +#endif
>  
> -        addi    %r1,%r1,160		# restore stack
> +        addi    %r1,%r1,STACK_SIZE	# restore stack
>          bctr				# jump to target
>  
>  


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