6.6-stable review patch. If anyone has any objections, please let me know.
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From: Kevin Loughlin kevinloughlin@google.com
[ Upstream commit 72dafb567760320f2de7447cd6e979bf9d4e5d17 ]
The following commit:
1c811d403afd ("x86/sev: Fix position dependent variable references in startup code")
introduced RIP_REL_REF() to force RIP-relative accesses to global variables, as needed to prevent crashes during early SEV/SME startup code.
For completeness, RIP_REL_REF() should be used with additional variables during sme_enable():
https://lore.kernel.org/all/CAMj1kXHnA0fJu6zh634=fbJswp59kSRAbhW+ubDGj1+NYwZ...
Access these vars with RIP_REL_REF() to prevent problem reoccurence.
Fixes: 1c811d403afd ("x86/sev: Fix position dependent variable references in startup code") Signed-off-by: Kevin Loughlin kevinloughlin@google.com Signed-off-by: Ingo Molnar mingo@kernel.org Reviewed-by: Ard Biesheuvel ardb@kernel.org Reviewed-by: Tom Lendacky thomas.lendacky@amd.com Cc: Dave Hansen dave.hansen@linux.intel.com Link: https://lore.kernel.org/r/20241122202322.977678-1-kevinloughlin@google.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/mm/mem_encrypt_identity.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c index cc47a818a640a..075899e3fc8a4 100644 --- a/arch/x86/mm/mem_encrypt_identity.c +++ b/arch/x86/mm/mem_encrypt_identity.c @@ -562,7 +562,7 @@ void __head sme_enable(struct boot_params *bp) }
RIP_REL_REF(sme_me_mask) = me_mask; - physical_mask &= ~me_mask; - cc_vendor = CC_VENDOR_AMD; + RIP_REL_REF(physical_mask) &= ~me_mask; + RIP_REL_REF(cc_vendor) = CC_VENDOR_AMD; cc_set_mask(me_mask); }