From d68612b257b5f4ea2e6535859c5a26b10011a9df Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Tue, 28 Oct 2008 11:45:42 -0700 Subject: resources: fix x86info results ioremap.c:226 __ioremap_caller+0xf2/0x2d6() WARNINGs Impact: avoid false-positive WARN_ON() Andi Kleen reported: > When running x86info on a 2.6.27-git8 system I get > > resource map sanity check conflict: 0x9e000 0x9efff 0x10000 0x9e7ff System RAM > ------------[ cut here ]------------ > WARNING: at /home/lsrc/linux/arch/x86/mm/ioremap.c:226 __ioremap_caller+0xf2/0x2d6() > ... Some of the pages below the 1MB ISA addresses will be shared typically by both BIOS and system usable RAM. For example: BIOS-e820: 0000000000000000 - 000000000009f800 (usable) BIOS-e820: 000000000009f800 - 00000000000a0000 (reserved) x86info reads the low physical address using /dev/mem, which internally uses ioremap() for accessing non RAM pages. ioremap() of such low pages conflicts with multiple resource entities leading to the above warning. Change the iomem_map_sanity_check() to allow mapping a page spanning multiple resource entities (minimum granularity that one can map is a page anyhow). Signed-off-by: Suresh Siddha Signed-off-by: Ingo Molnar --- kernel/resource.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel/resource.c') diff --git a/kernel/resource.c b/kernel/resource.c index 7fec0e427234..6aac5c60b25d 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -17,6 +17,7 @@ #include #include #include +#include #include @@ -849,7 +850,8 @@ int iomem_map_sanity_check(resource_size_t addr, unsigned long size) continue; if (p->end < addr) continue; - if (p->start <= addr && (p->end >= addr + size - 1)) + if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && + PFN_DOWN(p->end) >= PFN_DOWN(addr + size - 1)) continue; printk(KERN_WARNING "resource map sanity check conflict: " "0x%llx 0x%llx 0x%llx 0x%llx %s\n", -- cgit v1.2.2 From 42c0202363194007a1ac377d047a95aa39246eb0 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 1 Nov 2008 09:53:58 -0700 Subject: reserve_region_with_split: Fix GFP_KERNEL usage under spinlock This one apparently doesn't generate any warnings, because the function is only used during system bootup, when the warnings are disabled. But it's still very wrong. The __reserve_region_with_split() function is called with the resource_lock held for writing, so it must only ever do GFP_ATOMIC allocations. Signed-off-by: Linus Torvalds --- kernel/resource.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/resource.c') diff --git a/kernel/resource.c b/kernel/resource.c index 6aac5c60b25d..4337063663ef 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -523,7 +523,7 @@ static void __init __reserve_region_with_split(struct resource *root, { struct resource *parent = root; struct resource *conflict; - struct resource *res = kzalloc(sizeof(*res), GFP_KERNEL); + struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC); if (!res) return; -- cgit v1.2.2