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powerpc: Fix kernel thread creation on ABIv2

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Change how we setup registers for ret_from_kernel_thread. In
ABIv1, instead of passing a function descriptor in, dereference
it and pass the target in directly.

Use ppc_global_function_entry to get it right on both ABIv1 and ABIv2.

Signed-off-by: Anton Blanchard <anton@samba.org>
This commit is contained in:
Anton Blanchard 2014-02-04 16:08:51 +11:00
parent b86206e4c3
commit 7cedd6014b
2 changed files with 8 additions and 13 deletions
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4
arch/powerpc/kernel/entry_64.S
View File

@ -378,9 +378,11 @@ _GLOBAL(ret_from_fork)
_GLOBAL(ret_from_kernel_thread)
bl schedule_tail
REST_NVGPRS(r1)
ld r14, 0(r14)
mtlr r14
mr r3,r15
#if defined(_CALL_ELF) && _CALL_ELF == 2
mr r12,r14
#endif
blrl
li r3,0
b syscall_exit

17
arch/powerpc/kernel/process.c
View File

@ -54,6 +54,7 @@
#ifdef CONFIG_PPC64
#include <asm/firmware.h>
#endif
#include <asm/code-patching.h>
#include <linux/kprobes.h>
#include <linux/kdebug.h>
@ -1108,7 +1109,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
struct thread_info *ti = (void *)task_stack_page(p);
memset(childregs, 0, sizeof(struct pt_regs));
childregs->gpr[1] = sp + sizeof(struct pt_regs);
childregs->gpr[14] = usp; /* function */
/* function */
if (usp)
childregs->gpr[14] = ppc_function_entry((void *)usp);
#ifdef CONFIG_PPC64
clear_tsk_thread_flag(p, TIF_32BIT);
childregs->softe = 1;
@ -1187,17 +1190,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
if (cpu_has_feature(CPU_FTR_HAS_PPR))
p->thread.ppr = INIT_PPR;
#endif
/*
* The PPC64 ABI makes use of a TOC to contain function
* pointers. The function (ret_from_except) is actually a pointer
* to the TOC entry. The first entry is a pointer to the actual
* function.
*/
#ifdef CONFIG_PPC64
kregs->nip = *((unsigned long *)f);
#else
kregs->nip = (unsigned long)f;
#endif
kregs->nip = ppc_function_entry(f);
return 0;
}