4.19-stable review patch. If anyone has any objections, please let me know.
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From: Juergen Gross jgross@suse.com
[ Upstream commit fac1bceeeb04886fc2ee952672e6e6c85ce41dca ]
When running as a Xen PV dom0 the kernel is loaded by the hypervisor using a different memory map than that of the host. In order to minimize the required changes in the kernel, the kernel adapts its memory map to that of the host. In order to do that it is checking for conflicts of its load address with the host memory map.
Unfortunately the tested memory range does not include the .brk area, which might result in crashes or memory corruption when this area does conflict with the memory map of the host.
Fix the test by using the _end label instead of __bss_stop.
Fixes: 808fdb71936c ("xen: check for kernel memory conflicting with memory layout")
Signed-off-by: Juergen Gross jgross@suse.com Tested-by: Marek Marczykowski-Górecki marmarek@invisiblethingslab.com Reviewed-by: Jan Beulich jbeulich@suse.com Signed-off-by: Juergen Gross jgross@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/xen/setup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 075ed47993bbf..69fd1134b7fcf 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -862,7 +862,7 @@ char * __init xen_memory_setup(void) * to relocating (and even reusing) pages with kernel text or data. */ if (xen_is_e820_reserved(__pa_symbol(_text), - __pa_symbol(__bss_stop) - __pa_symbol(_text))) { + __pa_symbol(_end) - __pa_symbol(_text))) { xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n"); BUG(); }