[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH] xen/setup: add paranoid index check and warning
In a call to set_phys_range_identity, i-1 is used without checking that i is non-zero. Although unlikely, a bug in the code before it could cause the value to be 0, leading to erroneous behavior. This patch adds a check against 0 value and a corresponding warning. Signed-off-by: Martin Kelly <martkell@xxxxxxxxxx> --- arch/x86/xen/setup.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index af72161..26e39af 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -671,7 +671,10 @@ char * __init xen_memory_setup(void) * PFNs above MAX_P2M_PFN are considered identity mapped as * well. */ - set_phys_range_identity(map[i-1].addr / PAGE_SIZE, ~0ul); + if (i > 0) + set_phys_range_identity(map[i-1].addr / PAGE_SIZE, ~0ul); + else + WARN(1, "Something went wrong clamping memory to a factor of EXTRA_MEM_RATIO!"); /* * In domU, the ISA region is normal, usable memory, but we -- 2.1.1 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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