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Message-Id: <1235785882-17580-6-git-send-email-jeremy@goop.org> Date: Fri, 27 Feb 2009 17:51:22 -0800 From: Jeremy Fitzhardinge <jeremy@...p.org> To: "H. Peter Anvin" <hpa@...or.com> Cc: the arch/x86 maintainers <x86@...nel.org>, Linux Kernel Mailing List <linux-kernel@...r.kernel.org>, Jeremy Fitzhardinge <jeremy.fitzhardinge@...rix.com> Subject: [PATCH] x86: leave _brk_end defined From: Jeremy Fitzhardinge <jeremy.fitzhardinge@...rix.com> highmap_end_pfn refers to _brk_end, so leave it as normal data with a meaningful value. Make extend_brk() check for a NULL _brk_start to look for uses after the brk memory has been reserved and locked down. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@...rix.com> --- arch/x86/kernel/setup.c | 5 +++-- 1 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 1d4fe19..11c4198 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -116,7 +116,7 @@ unsigned int boot_cpu_id __read_mostly; extern char __brk_base[]; __initdata unsigned long _brk_start = (unsigned long)__brk_base; -__initdata unsigned long _brk_end = (unsigned long)&__brk_base; +unsigned long _brk_end = (unsigned long)&__brk_base; #ifdef CONFIG_X86_64 int default_cpu_present_to_apicid(int mps_cpu) @@ -337,6 +337,7 @@ void * __init extend_brk(size_t size, size_t align) size_t mask = align - 1; void *ret; + BUG_ON(_brk_start == 0); BUG_ON(align & mask); _brk_end = (_brk_end + mask) & ~mask; @@ -352,7 +353,7 @@ static void __init reserve_brk(void) if (_brk_end > _brk_start) reserve_early(__pa(_brk_start), __pa(_brk_end), "BRK"); - _brk_end = _brk_start = 0xdeadb00c + POISON_POINTER_DELTA; + _brk_start = 0; } static void __init reserve_initrd(void) -- 1.6.0.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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