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Message-ID: <163938901224.23020.15161128488578371433.tip-bot2@tip-bot2>
Date: Mon, 13 Dec 2021 09:50:12 -0000
From: "tip-bot2 for Peter Zijlstra" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: "Peter Zijlstra (Intel)" <peterz@...radead.org>,
Josh Poimboeuf <jpoimboe@...hat.com>, x86@...nel.org,
linux-kernel@...r.kernel.org
Subject: [tip: x86/core] x86/sgx: Remove .fixup usage
The following commit has been merged into the x86/core branch of tip:
Commit-ID: 5ce8e39f55521c762f0e6d1bba9597284b1f2e69
Gitweb: https://git.kernel.org/tip/5ce8e39f55521c762f0e6d1bba9597284b1f2e69
Author: Peter Zijlstra <peterz@...radead.org>
AuthorDate: Wed, 10 Nov 2021 11:01:20 +01:00
Committer: Peter Zijlstra <peterz@...radead.org>
CommitterDate: Sat, 11 Dec 2021 09:09:49 +01:00
x86/sgx: Remove .fixup usage
Create EX_TYPE_FAULT_SGX which does as EX_TYPE_FAULT does, except adds
this extra bit that SGX really fancies having.
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@...hat.com>
Link: https://lore.kernel.org/r/20211110101325.961246679@infradead.org
---
arch/x86/include/asm/extable_fixup_types.h | 2 +-
arch/x86/include/asm/sgx.h | 18 +++++++++++-
arch/x86/kernel/cpu/sgx/encls.h | 36 ++-------------------
arch/x86/mm/extable.c | 10 ++++++-
4 files changed, 35 insertions(+), 31 deletions(-)
diff --git a/arch/x86/include/asm/extable_fixup_types.h b/arch/x86/include/asm/extable_fixup_types.h
index 31ad42f..8278ed2 100644
--- a/arch/x86/include/asm/extable_fixup_types.h
+++ b/arch/x86/include/asm/extable_fixup_types.h
@@ -48,4 +48,6 @@
#define EX_TYPE_ZERO_REG (EX_TYPE_IMM_REG | EX_DATA_IMM(0))
#define EX_TYPE_ONE_REG (EX_TYPE_IMM_REG | EX_DATA_IMM(1))
+#define EX_TYPE_FAULT_SGX 18
+
#endif
diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h
index 05f3e21..3f9334e 100644
--- a/arch/x86/include/asm/sgx.h
+++ b/arch/x86/include/asm/sgx.h
@@ -46,6 +46,24 @@ enum sgx_encls_function {
};
/**
+ * SGX_ENCLS_FAULT_FLAG - flag signifying an ENCLS return code is a trapnr
+ *
+ * ENCLS has its own (positive value) error codes and also generates
+ * ENCLS specific #GP and #PF faults. And the ENCLS values get munged
+ * with system error codes as everything percolates back up the stack.
+ * Unfortunately (for us), we need to precisely identify each unique
+ * error code, e.g. the action taken if EWB fails varies based on the
+ * type of fault and on the exact SGX error code, i.e. we can't simply
+ * convert all faults to -EFAULT.
+ *
+ * To make all three error types coexist, we set bit 30 to identify an
+ * ENCLS fault. Bit 31 (technically bits N:31) is used to differentiate
+ * between positive (faults and SGX error codes) and negative (system
+ * error codes) values.
+ */
+#define SGX_ENCLS_FAULT_FLAG 0x40000000
+
+/**
* enum sgx_return_code - The return code type for ENCLS, ENCLU and ENCLV
* %SGX_NOT_TRACKED: Previous ETRACK's shootdown sequence has not
* been completed yet.
diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h
index 9b20484..fa04a73 100644
--- a/arch/x86/kernel/cpu/sgx/encls.h
+++ b/arch/x86/kernel/cpu/sgx/encls.h
@@ -11,26 +11,8 @@
#include <asm/traps.h>
#include "sgx.h"
-/**
- * ENCLS_FAULT_FLAG - flag signifying an ENCLS return code is a trapnr
- *
- * ENCLS has its own (positive value) error codes and also generates
- * ENCLS specific #GP and #PF faults. And the ENCLS values get munged
- * with system error codes as everything percolates back up the stack.
- * Unfortunately (for us), we need to precisely identify each unique
- * error code, e.g. the action taken if EWB fails varies based on the
- * type of fault and on the exact SGX error code, i.e. we can't simply
- * convert all faults to -EFAULT.
- *
- * To make all three error types coexist, we set bit 30 to identify an
- * ENCLS fault. Bit 31 (technically bits N:31) is used to differentiate
- * between positive (faults and SGX error codes) and negative (system
- * error codes) values.
- */
-#define ENCLS_FAULT_FLAG 0x40000000
-
/* Retrieve the encoded trapnr from the specified return code. */
-#define ENCLS_TRAPNR(r) ((r) & ~ENCLS_FAULT_FLAG)
+#define ENCLS_TRAPNR(r) ((r) & ~SGX_ENCLS_FAULT_FLAG)
/* Issue a WARN() about an ENCLS function. */
#define ENCLS_WARN(r, name) { \
@@ -50,7 +32,7 @@
*/
static inline bool encls_faulted(int ret)
{
- return ret & ENCLS_FAULT_FLAG;
+ return ret & SGX_ENCLS_FAULT_FLAG;
}
/**
@@ -88,11 +70,7 @@ static inline bool encls_failed(int ret)
asm volatile( \
"1: .byte 0x0f, 0x01, 0xcf;\n\t" \
"2:\n" \
- ".section .fixup,\"ax\"\n" \
- "3: orl $"__stringify(ENCLS_FAULT_FLAG)",%%eax\n" \
- " jmp 2b\n" \
- ".previous\n" \
- _ASM_EXTABLE_FAULT(1b, 3b) \
+ _ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_FAULT_SGX) \
: "=a"(ret) \
: "a"(rax), inputs \
: "memory", "cc"); \
@@ -127,7 +105,7 @@ static inline bool encls_failed(int ret)
*
* Return:
* 0 on success,
- * trapnr with ENCLS_FAULT_FLAG set on fault
+ * trapnr with SGX_ENCLS_FAULT_FLAG set on fault
*/
#define __encls_N(rax, rbx_out, inputs...) \
({ \
@@ -136,11 +114,7 @@ static inline bool encls_failed(int ret)
"1: .byte 0x0f, 0x01, 0xcf;\n\t" \
" xor %%eax,%%eax;\n" \
"2:\n" \
- ".section .fixup,\"ax\"\n" \
- "3: orl $"__stringify(ENCLS_FAULT_FLAG)",%%eax\n" \
- " jmp 2b\n" \
- ".previous\n" \
- _ASM_EXTABLE_FAULT(1b, 3b) \
+ _ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_FAULT_SGX) \
: "=a"(ret), "=b"(rbx_out) \
: "a"(rax), inputs \
: "memory"); \
diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c
index 717cd35..c869f43 100644
--- a/arch/x86/mm/extable.c
+++ b/arch/x86/mm/extable.c
@@ -10,6 +10,7 @@
#include <asm/traps.h>
#include <asm/kdebug.h>
#include <asm/insn-eval.h>
+#include <asm/sgx.h>
static inline unsigned long *pt_regs_nr(struct pt_regs *regs, int nr)
{
@@ -47,6 +48,13 @@ static bool ex_handler_fault(const struct exception_table_entry *fixup,
return ex_handler_default(fixup, regs);
}
+static bool ex_handler_sgx(const struct exception_table_entry *fixup,
+ struct pt_regs *regs, int trapnr)
+{
+ regs->ax = trapnr | SGX_ENCLS_FAULT_FLAG;
+ return ex_handler_default(fixup, regs);
+}
+
/*
* Handler for when we fail to restore a task's FPU state. We should never get
* here because the FPU state of a task using the FPU (task->thread.fpu.state)
@@ -207,6 +215,8 @@ int fixup_exception(struct pt_regs *regs, int trapnr, unsigned long error_code,
return ex_handler_pop_zero(e, regs);
case EX_TYPE_IMM_REG:
return ex_handler_imm_reg(e, regs, reg, imm);
+ case EX_TYPE_FAULT_SGX:
+ return ex_handler_sgx(e, regs, trapnr);
}
BUG();
}
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