x86/kexec: Fix bug with call depth tracking

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The call to cc_platform_has() triggers a fault and system crash if call depth
tracking is active because the GS segment has been reset by load_segments() and
GS_BASE is now 0 but call depth tracking uses per-CPU variables to operate.

Call cc_platform_has() earlier in the function when GS is still valid.

  [ bp: Massage. ]

Fixes: 5d8213864a ("x86/retbleed: Add SKL return thunk")
Signed-off-by: David Kaplan <david.kaplan@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/20240603083036.637-1-bp@kernel.org

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David Kaplan 2024-06-02 13:19:09 -05:00 • committed by Borislav Petkov (AMD)

parent c3f38fa61a

commit 93c1800b37

1 changed files with 9 additions and 2 deletions

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arch/x86/kernel/machine_kexec_64.c

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