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Jason Andryuk
36104cb901
Commit2cc42bac1c("x86-64/Xen: eliminate W+X mappings") introduced a call to get_cpu_cap, which is fstack-protected. This is works on x86-64 as commit4f277295e5("x86/xen: init %gs very early to avoid page faults with stack protector") ensures the stack protector is configured, but it it did not cover x86-32. Delay calling get_cpu_cap until after xen_setup_gdt has initialized the stack canary. Without this, a 32bit PV machine crashes early in boot. (XEN) Domain 0 (vcpu#0) crashed on cpu#0: (XEN) ----[ Xen-4.6.6-xc x86_64 debug=n Tainted: C ]---- (XEN) CPU: 0 (XEN) RIP: e019:[<00000000c10362f8>] And the PV kernel IP corresponds to init_scattered_cpuid_features 0xc10362f8 <+24>: mov %gs:0x14,%eax Fixes2cc42bac1c("x86-64/Xen: eliminate W+X mappings") Signed-off-by: Jason Andryuk <jandryuk@gmail.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.