From cafeba3c2a1f015e26feb5629ae696e84cfb5ec9 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Sat, 3 Aug 2024 08:01:22 +0200 Subject: [PATCH] xen: use correct end address of kernel for conflict checking MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ 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 Tested-by: Marek Marczykowski-Górecki Reviewed-by: Jan Beulich Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin --- 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 380591028cb8..d44d6d8b3319 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -825,7 +825,7 @@ 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(); }