Messages in this thread Patch in this message | | | From | Andy Lutomirski <> | Subject | [PATCH v5 1/7] x86,mm: Ensure correct alignment of the fixmap | Date | Mon, 5 May 2014 12:19:31 -0700 |
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The early_ioremap code requires that its buffers not span a PMD boundary. The logic for ensuring that only works if the fixmap is aligned, so assert that it's aligned correctly.
To make this work reliably, reserve_top_address needs to be adjusted.
Signed-off-by: Andy Lutomirski <luto@amacapital.net> --- arch/x86/mm/ioremap.c | 6 ++++++ arch/x86/mm/pgtable.c | 6 +++--- 2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 597ac15..6ef98c5 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -355,6 +355,12 @@ void __init early_ioremap_init(void) { pmd_t *pmd; +#ifdef CONFIG_X86_64 + BUILD_BUG_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1)); +#else + WARN_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1)); +#endif + early_ioremap_setup(); pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN)); diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index c96314a..5f8bdda 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -449,9 +449,9 @@ void __init reserve_top_address(unsigned long reserve) { #ifdef CONFIG_X86_32 BUG_ON(fixmaps_set > 0); - printk(KERN_INFO "Reserving virtual address space above 0x%08x\n", - (int)-reserve); - __FIXADDR_TOP = -reserve - PAGE_SIZE; + __FIXADDR_TOP = round_down(-reserve, 1 << PMD_SHIFT) - PAGE_SIZE; + printk(KERN_INFO "Reserving virtual address space above 0x%08lx (rounded to 0x%08lx)\n", + -reserve, __FIXADDR_TOP + PAGE_SIZE); #endif } -- 1.9.0
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