From: "tip-bot2 for Joerg Roedel" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Joerg Roedel <jroedel@suse.de>, Borislav Petkov <bp@suse.de>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: [tip: x86/sev] x86/sev: Propagate #GP if getting linear instruction address failed
Date: Tue, 15 Jun 2021 10:51:55 -0000 [thread overview]
Message-ID: <162375431608.19906.8487681008973797088.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20210614135327.9921-7-joro@8bytes.org>
The following commit has been merged into the x86/sev branch of tip:
Commit-ID: 07570cef5e5c3fcec40f82a9075abb4c1da63319
Gitweb: https://git.kernel.org/tip/07570cef5e5c3fcec40f82a9075abb4c1da63319
Author: Joerg Roedel <jroedel@suse.de>
AuthorDate: Mon, 14 Jun 2021 15:53:27 +02:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Tue, 15 Jun 2021 11:55:26 +02:00
x86/sev: Propagate #GP if getting linear instruction address failed
When an instruction is fetched from user-space, segmentation needs to
be taken into account. This means that getting the linear address of an
instruction can fail. Hardware would raise a #GP exception in that case,
but the #VC exception handler would emulate it as a page-fault.
The insn_fetch_from_user*() functions now provide the relevant
information in case of a failure. Use that and propagate a #GP when the
linear address of an instruction to fetch could not be calculated.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210614135327.9921-7-joro@8bytes.org
---
arch/x86/kernel/sev.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index a1eeaa7..8178db0 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -261,11 +261,18 @@ static enum es_result __vc_decode_user_insn(struct es_em_ctxt *ctxt)
int insn_bytes;
insn_bytes = insn_fetch_from_user_inatomic(ctxt->regs, buffer);
- if (insn_bytes <= 0) {
+ if (insn_bytes == 0) {
+ /* Nothing could be copied */
ctxt->fi.vector = X86_TRAP_PF;
ctxt->fi.error_code = X86_PF_INSTR | X86_PF_USER;
ctxt->fi.cr2 = ctxt->regs->ip;
return ES_EXCEPTION;
+ } else if (insn_bytes == -EINVAL) {
+ /* Effective RIP could not be calculated */
+ ctxt->fi.vector = X86_TRAP_GP;
+ ctxt->fi.error_code = 0;
+ ctxt->fi.cr2 = 0;
+ return ES_EXCEPTION;
}
if (!insn_decode_from_regs(&ctxt->insn, ctxt->regs, buffer, insn_bytes))
prev parent reply other threads:[~2021-06-15 10:52 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-14 13:53 [PATCH v5 0/6] x86/sev-es: Fixes for SEV-ES Guest Support Joerg Roedel
2021-06-14 13:53 ` [PATCH v5 1/6] x86/sev-es: Fix error message in runtime #VC handler Joerg Roedel
2021-06-15 10:51 ` [tip: x86/sev] x86/sev: " tip-bot2 for Joerg Roedel
2021-06-14 13:53 ` [PATCH v5 2/6] x86/sev-es: Make sure IRQs are disabled while GHCB is active Joerg Roedel
2021-06-14 16:25 ` Borislav Petkov
2021-06-14 16:30 ` Borislav Petkov
2021-06-15 9:37 ` Joerg Roedel
2021-06-14 13:53 ` [PATCH v5 3/6] x86/sev-es: Split up runtime #VC handler for correct state tracking Joerg Roedel
2021-06-16 16:04 ` Peter Zijlstra
2021-06-16 19:01 ` Joerg Roedel
2021-06-14 13:53 ` [PATCH v5 4/6] x86/insn-eval: Make 0 a valid RIP for insn_get_effective_ip() Joerg Roedel
2021-06-15 10:51 ` [tip: x86/sev] " tip-bot2 for Joerg Roedel
2021-06-14 13:53 ` [PATCH v5 5/6] x86/insn: Extend error reporting from insn_fetch_from_user[_inatomic]() Joerg Roedel
2021-06-15 10:51 ` [tip: x86/sev] " tip-bot2 for Joerg Roedel
2021-06-14 13:53 ` [PATCH v5 6/6] x86/sev-es: Propagate #GP if getting linear instruction address failed Joerg Roedel
2021-06-15 10:51 ` tip-bot2 for Joerg Roedel [this message]
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