From: Borislav Petkov <bp@alien8.de>
To: X86 ML <x86@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH v2 12/21] x86/sev-es: Split vc_decode_insn()
Date: Wed, 24 Feb 2021 12:02:24 +0100 [thread overview]
Message-ID: <20210224110233.19715-13-bp@alien8.de> (raw)
In-Reply-To: <20210224110233.19715-1-bp@alien8.de>
From: Borislav Petkov <bp@suse.de>
Split it into two helpers - a user- and a kernel-mode one for
readability. Yes, the original function body is not that convoluted but
splitting it makes following through that code trivial than having to
pay attention to each little difference when in user or in kernel mode.
No functional changes.
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/kernel/sev-es.c | 59 ++++++++++++++++++++++++++--------------
1 file changed, 38 insertions(+), 21 deletions(-)
diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c
index 248d14ae5602..6513e94d53f2 100644
--- a/arch/x86/kernel/sev-es.c
+++ b/arch/x86/kernel/sev-es.c
@@ -241,41 +241,58 @@ static int vc_fetch_insn_kernel(struct es_em_ctxt *ctxt,
return copy_from_kernel_nofault(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE);
}
-static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
+static enum es_result __vc_decode_user_insn(struct es_em_ctxt *ctxt)
{
char buffer[MAX_INSN_SIZE];
enum es_result ret;
int res;
- if (user_mode(ctxt->regs)) {
- res = insn_fetch_from_user(ctxt->regs, buffer);
- if (!res) {
- 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;
- }
+ res = insn_fetch_from_user(ctxt->regs, buffer);
+ if (!res) {
+ 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;
+ }
- if (!insn_decode_from_regs(&ctxt->insn, ctxt->regs, buffer, res))
- return ES_DECODE_FAILED;
- } else {
- res = vc_fetch_insn_kernel(ctxt, buffer);
- if (res) {
- ctxt->fi.vector = X86_TRAP_PF;
- ctxt->fi.error_code = X86_PF_INSTR;
- ctxt->fi.cr2 = ctxt->regs->ip;
- return ES_EXCEPTION;
- }
+ if (!insn_decode_from_regs(&ctxt->insn, ctxt->regs, buffer, res))
+ return ES_DECODE_FAILED;
+
+ ret = ctxt->insn.immediate.got ? ES_OK : ES_DECODE_FAILED;
+
+ return ret;
+}
- insn_init(&ctxt->insn, buffer, MAX_INSN_SIZE - res, 1);
- insn_get_length(&ctxt->insn);
+static enum es_result __vc_decode_kern_insn(struct es_em_ctxt *ctxt)
+{
+ char buffer[MAX_INSN_SIZE];
+ enum es_result ret;
+ int res;
+
+ res = vc_fetch_insn_kernel(ctxt, buffer);
+ if (res) {
+ ctxt->fi.vector = X86_TRAP_PF;
+ ctxt->fi.error_code = X86_PF_INSTR;
+ ctxt->fi.cr2 = ctxt->regs->ip;
+ return ES_EXCEPTION;
}
+ insn_init(&ctxt->insn, buffer, MAX_INSN_SIZE - res, 1);
+ insn_get_length(&ctxt->insn);
+
ret = ctxt->insn.immediate.got ? ES_OK : ES_DECODE_FAILED;
return ret;
}
+static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
+{
+ if (user_mode(ctxt->regs))
+ return __vc_decode_user_insn(ctxt);
+ else
+ return __vc_decode_kern_insn(ctxt);
+}
+
static enum es_result vc_write_mem(struct es_em_ctxt *ctxt,
char *dst, char *buf, size_t size)
{
--
2.29.2
next prev parent reply other threads:[~2021-02-24 11:12 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-24 11:02 [PATCH v2 00/21] x86/insn: Add an insn_decode() API Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 01/21] x86/insn: Rename insn_decode() to insn_decode_from_regs() Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 02/21] x86/insn: Add @buf_len param to insn_init() kernel-doc comment Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 03/21] x86/insn: Add a __ignore_sync_check__ marker Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 04/21] x86/insn: Add an insn_decode() API Borislav Petkov
2021-02-26 15:45 ` Masami Hiramatsu
2021-02-26 18:30 ` Borislav Petkov
2021-02-28 14:51 ` Masami Hiramatsu
2021-02-24 11:02 ` [PATCH v2 05/21] x86/insn-eval: Handle return values from the decoder Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 06/21] x86/boot/compressed/sev-es: Convert to insn_decode() Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 07/21] perf/x86/intel/ds: Check insn_get_length() retval Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 08/21] perf/x86/intel/ds: Check return values of insn decoder functions Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 09/21] x86/alternative: Use insn_decode() Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 10/21] x86/mce: Convert to insn_decode() Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 11/21] x86/kprobes: " Borislav Petkov
2021-02-24 11:02 ` Borislav Petkov [this message]
2021-02-24 11:02 ` [PATCH v2 13/21] x86/sev-es: " Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 14/21] x86/traps: " Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 15/21] x86/uprobes: " Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 16/21] x86/tools/insn_decoder_test: " Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 17/21] tools/objtool: " Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 18/21] x86/tools/insn_sanity: " Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 19/21] tools/perf: " Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 20/21] x86/insn: Remove kernel_insn_init() Borislav Petkov
2021-02-24 11:02 ` [PATCH v2 21/21] x86/insn: Make insn_complete() static Borislav Petkov
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