Patchwork ARM: Clear icache when creating a closure

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Submitter Andrew Haley
Date July 26, 2011, 1:03 p.m.
Message ID <4E2EBB34.10604@redhat.com>
Download mbox | patch
Permalink /patch/106869/
State New
Headers show

Comments

Andrew Haley - July 26, 2011, 1:03 p.m.
On 07/25/2011 10:33 AM, Andrew Haley wrote:
> On 21/07/11 16:33, Joseph S. Myers wrote:
>> My suggestion would be putting the instruction sequence in a .s file, 
>> rather than hardcoding the instruction encodings here, and writing the 
>> code to read from the sequence as assembled by the assembler.  That way it 
>> will have the appropriate mapping symbols to mark it as ARM-mode code and 
>> the linker will deal with adjusting endianness, so you don't need to test 
>> for BE-8 at all.

I did this, and it passes the testsuite.  Is it OK?

Andrew.


2011-07-26  Andrew Haley  <aph@redhat.com>

	* src/arm/ffi.c (FFI_INIT_TRAMPOLINE): Remove hard-coded assembly
	instructions.
	* src/arm/sysv.S (ffi_arm_trampoline): Put them here instead.

Patch

Index: src/arm/ffi.c
===================================================================
--- src/arm/ffi.c	(revision 176744)
+++ src/arm/ffi.c	(working copy)
@@ -337,14 +337,14 @@ 

 /* How to make a trampoline.  */

+extern unsigned int ffi_arm_trampoline[3];
+
 #define FFI_INIT_TRAMPOLINE(TRAMP,FUN,CTX)				\
 ({ unsigned char *__tramp = (unsigned char*)(TRAMP);			\
    unsigned int  __fun = (unsigned int)(FUN);				\
    unsigned int  __ctx = (unsigned int)(CTX);				\
    unsigned char *insns = (unsigned char *)(CTX);                       \
-   *(unsigned int*) &__tramp[0] = 0xe92d000f; /* stmfd sp!, {r0-r3} */	\
-   *(unsigned int*) &__tramp[4] = 0xe59f0000; /* ldr r0, [pc] */	\
-   *(unsigned int*) &__tramp[8] = 0xe59ff000; /* ldr pc, [pc] */	\
+   memcpy (__tramp, ffi_arm_trampoline, sizeof ffi_arm_trampoline);     \
    *(unsigned int*) &__tramp[12] = __ctx;				\
    *(unsigned int*) &__tramp[16] = __fun;				\
    __clear_cache((&__tramp[0]), (&__tramp[19])); /* Clear data mapping.  */ \
Index: src/arm/sysv.S
===================================================================
--- src/arm/sysv.S	(revision 176744)
+++ src/arm/sysv.S	(working copy)
@@ -461,6 +461,11 @@ 
 	UNWIND .fnend
         .size    CNAME(ffi_closure_VFP),.ffi_closure_VFP_end-CNAME(ffi_closure_VFP)

+ENTRY(ffi_arm_trampoline)
+	stmfd sp!, {r0-r3}
+	ldr r0, [pc]
+	ldr pc, [pc]
+
 #if defined __ELF__ && defined __linux__
 	.section	.note.GNU-stack,"",%progbits
 #endif