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Commit 8827247f authored by Wang Chen's avatar Wang Chen Committed by Ingo Molnar
Browse files

x86: don't define __this_fixmap_does_not_exist() 



Impact: improve out-of-range fixmap index debugging

Commit "1b42f516"
defined the __this_fixmap_does_not_exist() function
with a WARN_ON(1) in it.

This causes the linker to not report an error when
__this_fixmap_does_not_exist() is called with a
non-constant parameter.

Ingo defined __this_fixmap_does_not_exist() because he
wanted to get virt addresses of fix memory of nest level
by non-constant index.

But we can fix this and still keep the link-time check:

We can get the four slot virt addresses on link time and
store them to array slot_virt[].

Then we can then refer the slot_virt with non-constant index,
in the ioremap-leak detection code.

Signed-off-by: default avatarWang Chen <wangchen@cn.fujitsu.com>
LKML-Reference: <49B2075B.4070509@cn.fujitsu.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 31bbed52

arch/x86/mm/ioremap.c

+11 −8
Original line number Diff line number Diff line
@@ -504,13 +504,19 @@ static inline pte_t * __init early_ioremap_pte(unsigned long addr) 
	return &bm_pte[pte_index(addr)];

}



static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata;



void __init early_ioremap_init(void)

{

	pmd_t *pmd;

	int i;



	if (early_ioremap_debug)

		printk(KERN_INFO "early_ioremap_init()\n");



	for (i = 0; i < FIX_BTMAPS_SLOTS; i++)

		slot_virt[i] = fix_to_virt(FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*i);



	pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));

	memset(bm_pte, 0, sizeof(bm_pte));

	pmd_populate_kernel(&init_mm, pmd, bm_pte);
@@ -577,6 +583,7 @@ static inline void __init early_clear_fixmap(enum fixed_addresses idx) 


static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata;

static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;



static int __init check_early_ioremap_leak(void)

{

	int count = 0;
@@ -598,7 +605,8 @@ static int __init check_early_ioremap_leak(void) 
}

late_initcall(check_early_ioremap_leak);



static void __init __iomem *__early_ioremap(unsigned long phys_addr, unsigned long size, pgprot_t prot)

static void __init __iomem *

__early_ioremap(unsigned long phys_addr, unsigned long size, pgprot_t prot)

{

	unsigned long offset, last_addr;

	unsigned int nrpages;
@@ -664,9 +672,9 @@ static void __init __iomem *__early_ioremap(unsigned long phys_addr, unsigned lo 
		--nrpages;

	}

	if (early_ioremap_debug)

		printk(KERN_CONT "%08lx + %08lx\n", offset, fix_to_virt(idx0));

		printk(KERN_CONT "%08lx + %08lx\n", offset, slot_virt[slot]);



	prev_map[slot] = (void __iomem *)(offset + fix_to_virt(idx0));

	prev_map[slot] = (void __iomem *)(offset + slot_virt[slot]);

	return prev_map[slot];

}
@@ -734,8 +742,3 @@ void __init early_iounmap(void __iomem *addr, unsigned long size) 
	}

	prev_map[slot] = NULL;

}
 


void __this_fixmap_does_not_exist(void)

{

	WARN_ON(1);

}