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Peter Anvin" , xen-devel@lists.xenproject.org, =?utf-8?q?Marek_Marczykowski-G=C3=B3recki?= Subject: [PATCH 1/5] xen: use correct end address of kernel for conflict checking Date: Wed, 7 Aug 2024 12:41:06 +0200 Message-ID: <20240807104110.18117-2-jgross@suse.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240807104110.18117-1-jgross@suse.com> References: <20240807104110.18117-1-jgross@suse.com> MIME-Version: 1.0 X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Spamd-Result: default: False [-4.00 / 50.00]; REPLY(-4.00)[] X-Rspamd-Queue-Id: AA10021CFE X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Action: no action 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 withe 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 --- 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 806ddb2391d9..4bcc70a71b7d 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(); }