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| author | Jason Gunthorpe <jgg@nvidia.com> | 2020-11-17 20:20:26 +0100 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2020-11-17 20:20:26 +0100 |
| commit | bf3b7b7ba9e3db55d164ec7bf05e6947f79637cd (patch) | |
| tree | 7de81ebc8339c2a985b2af0e360368e281564c93 /arch/x86/kernel/head_64.S | |
| parent | RDMA/mlx5: Lower setting the umem's PAS for SRQ (diff) | |
| parent | IB/hfi1: Fix error return code in hfi1_init_dd() (diff) | |
| download | linux-bf3b7b7ba9e3db55d164ec7bf05e6947f79637cd.tar.xz linux-bf3b7b7ba9e3db55d164ec7bf05e6947f79637cd.zip | |
Merge branch 'for-rc' into rdma.git
From https://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git
The rc RDMA branch is needed due to dependencies on the next patches.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'arch/x86/kernel/head_64.S')
| -rw-r--r-- | arch/x86/kernel/head_64.S | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 7eb2a1c87969..3c417734790f 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -161,6 +161,21 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) /* Setup early boot stage 4-/5-level pagetables. */ addq phys_base(%rip), %rax + + /* + * For SEV guests: Verify that the C-bit is correct. A malicious + * hypervisor could lie about the C-bit position to perform a ROP + * attack on the guest by writing to the unencrypted stack and wait for + * the next RET instruction. + * %rsi carries pointer to realmode data and is callee-clobbered. Save + * and restore it. + */ + pushq %rsi + movq %rax, %rdi + call sev_verify_cbit + popq %rsi + + /* Switch to new page-table */ movq %rax, %cr3 /* Ensure I am executing from virtual addresses */ @@ -279,6 +294,7 @@ SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL) SYM_CODE_END(secondary_startup_64) #include "verify_cpu.S" +#include "sev_verify_cbit.S" #ifdef CONFIG_HOTPLUG_CPU /* |