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Commit 934d1585 authored by Andi Kleen's avatar Andi Kleen Committed by Ingo Molnar
Browse files

x86: remove set_kernel_exec() 



The SMP trampoline always runs in real mode, so making it executable
in the page tables doesn't make much sense because it executes
before page tables are set up. That was the only user of
set_kernel_exec(). Remove set_kernel_exec().

Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Acked-by: default avatarJan Beulich <jbeulich@novell.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 1e8e23bc

arch/x86/kernel/smpboot_32.c

+0 −11
Original line number Diff line number Diff line
@@ -107,7 +107,6 @@ u8 apicid_2_node[MAX_APICID]; 
extern const unsigned char trampoline_data [];

extern const unsigned char trampoline_end  [];

static unsigned char *trampoline_base;

static int trampoline_exec;



static void map_cpu_to_logical_apicid(void);
@@ -139,10 +138,6 @@ void __init smp_alloc_memory(void) 
	 */

	if (__pa(trampoline_base) >= 0x9F000)

		BUG();

	/*

	 * Make the SMP trampoline executable:

	 */

	trampoline_exec = set_kernel_exec((unsigned long)trampoline_base, 1);

}



/*
@@ -1290,12 +1285,6 @@ void __init native_smp_cpus_done(unsigned int max_cpus) 
	setup_ioapic_dest();

#endif

	zap_low_mappings();

#ifndef CONFIG_HOTPLUG_CPU

	/*

	 * Disable executability of the SMP trampoline:

	 */

	set_kernel_exec((unsigned long)trampoline_base, trampoline_exec);

#endif

}



void __init smp_intr_init(void)

arch/x86/mm/init_32.c

+0 −29
Original line number Diff line number Diff line
@@ -529,35 +529,6 @@ static void __init set_nx(void) 
	}

}



/*

 * Enables/disables executability of a given kernel page and

 * returns the previous setting.

 */

int __init set_kernel_exec(unsigned long vaddr, int enable)

{

	pte_t *pte;

	int ret = 1;

	int level;



	if (!nx_enabled)

		goto out;



	pte = lookup_address(vaddr, &level);

	BUG_ON(!pte);



	if (!pte_exec(*pte))

		ret = 0;



	if (enable)

		pte->pte_high &= ~(1 << (_PAGE_BIT_NX - 32));

	else

		pte->pte_high |= 1 << (_PAGE_BIT_NX - 32);

	pte_update_defer(&init_mm, vaddr, pte);

	__flush_tlb_all();

out:

	return ret;

}



#endif



/*

include/asm-x86/pgtable_32.h

+0 −12
Original line number Diff line number Diff line
@@ -184,18 +184,6 @@ static inline void clone_pgd_range(pgd_t *dst, pgd_t *src, int count) 
 */

extern pte_t *lookup_address(unsigned long address, int *level);



/*

 * Make a given kernel text page executable/non-executable.

 * Returns the previous executability setting of that page (which

 * is used to restore the previous state). Used by the SMP bootup code.

 * NOTE: this is an __init function for security reasons.

 */

#ifdef CONFIG_X86_PAE

 extern int set_kernel_exec(unsigned long vaddr, int enable);

#else

 static inline int set_kernel_exec(unsigned long vaddr, int enable) { return 0;}

#endif



#if defined(CONFIG_HIGHPTE)

#define pte_offset_map(dir, address) \

	((pte_t *)kmap_atomic_pte(pmd_page(*(dir)),KM_PTE0) + pte_index(address))