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Commit 7cedd601 authored by Anton Blanchard's avatar Anton Blanchard
Browse files

powerpc: Fix kernel thread creation on ABIv2 



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: default avatarAnton Blanchard <anton@samba.org>
parent b86206e4

arch/powerpc/kernel/entry_64.S

+3 −1
Original line number Diff line number Diff line
@@ -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

arch/powerpc/kernel/process.c

+5 −12
Original line number Diff line number Diff line
@@ -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;

}