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| author | Jason Andryuk <[email protected]> | 2018-03-19 16:58:04 +0000 |
|---|---|---|
| committer | Boris Ostrovsky <[email protected]> | 2018-03-21 12:29:04 +0000 |
| commit | 36104cb9012a82e73c32a3b709257766b16bcd1d (patch) | |
| tree | d1f809002dd821eace1c88fd0e6c5a443895bd8b /drivers/xen/xen-acpi-processor.c | |
| parent | xen: xenbus_dev_frontend: Verify body of XS_TRANSACTION_END (diff) | |
| download | kernel-36104cb9012a82e73c32a3b709257766b16bcd1d.tar.gz kernel-36104cb9012a82e73c32a3b709257766b16bcd1d.zip | |
x86/xen: Delay get_cpu_cap until stack canary is established
Commit 2cc42bac1c79 ("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 commit 4f277295e54c ("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
Fixes 2cc42bac1c79 ("x86-64/Xen: eliminate W+X mappings")
Signed-off-by: Jason Andryuk <[email protected]>
Reviewed-by: Boris Ostrovsky <[email protected]>
Signed-off-by: Boris Ostrovsky <[email protected]>
Diffstat (limited to 'drivers/xen/xen-acpi-processor.c')
0 files changed, 0 insertions, 0 deletions