Commit-ID: 855c743a27bb58a9a521bdc485ef5acfdb69badc Gitweb: http://git.kernel.org/tip/855c743a27bb58a9a521bdc485ef5acfdb69badc Author: Stanislaw Gruszka <sgruszka@xxxxxxxxxx> AuthorDate: Tue, 6 Dec 2011 09:08:34 +0100 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Tue, 6 Dec 2011 09:23:53 +0100 x86/mm: Initialize high mem before free_all_bootmem() Patch fixes a boot crash with pagealloc debugging enabled: Initializing HighMem for node 0 (000377fe:0003fff0) BUG: unable to handle kernel paging request at f6fefe80 IP: [<c1621ab5>] find_range_array+0x5e/0x69 [...] Call Trace: [<c1622064>] __get_free_all_memory_range+0x39/0xb4 [<c1620dd0>] add_highpages_with_active_regions+0x18/0x9b [<c1621a2e>] set_highmem_pages_init+0x70/0x90 [<c162122b>] mem_init+0x50/0x21b [<c16155bd>] start_kernel+0x1bf/0x31c [<c1615065>] i386_start_kernel+0x65/0x67 The crash happens when memblock wants to allocate big area for temporary "struct range" array and reuses pages from top of low memory, which were already passed to the buddy allocator. Reported-by: Ingo Molnar <mingo@xxxxxxx> Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx> Cc: linux-mm@xxxxxxxxx Cc: Mel Gorman <mgorman@xxxxxxx> Link: http://lkml.kernel.org/r/20111206080833.GB3105@xxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- arch/x86/mm/init_32.c | 13 +++++++++++-- 1 files changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index 3bebaed..a2fecb1 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -744,6 +744,17 @@ void __init mem_init(void) #ifdef CONFIG_FLATMEM BUG_ON(!mem_map); #endif + /* + * With CONFIG_DEBUG_PAGEALLOC initialization of highmem pages has to + * be done before free_all_bootmem(). Memblock use free low memory for + * temporary data (see find_range_array()) and for this purpose can use + * pages that was already passed to the buddy allocator, hence marked as + * not accessible in the page tables when compiled with + * CONFIG_DEBUG_PAGEALLOC. Otherwise order of initialization is not + * important here. + */ + set_highmem_pages_init(); + /* this will put all low memory onto the freelists */ totalram_pages += free_all_bootmem(); @@ -755,8 +766,6 @@ void __init mem_init(void) if (page_is_ram(tmp) && PageReserved(pfn_to_page(tmp))) reservedpages++; - set_highmem_pages_init(); - codesize = (unsigned long) &_etext - (unsigned long) &_text; datasize = (unsigned long) &_edata - (unsigned long) &_etext; initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin; -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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