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 <martk...@amazon.com>
---
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
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