From: Amit Daniel Kachhap <amit.kachhap@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Mark Rutland <mark.rutland@arm.com>,
Kees Cook <keescook@chromium.org>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Will Deacon <will.deacon@arm.com>,
Kristina Martsenko <kristina.martsenko@arm.com>,
James Morse <james.morse@arm.com>,
Ramana Radhakrishnan <ramana.radhakrishnan@arm.com>,
Amit Daniel Kachhap <amit.kachhap@arm.com>,
Vincenzo Frascino <Vincenzo.Frascino@arm.com>,
Dave Martin <Dave.Martin@arm.com>
Subject: [PATCH v2 02/14] arm64: install user ptrauth keys at kernel exit time
Date: Tue, 19 Nov 2019 18:02:14 +0530 [thread overview]
Message-ID: <1574166746-27197-3-git-send-email-amit.kachhap@arm.com> (raw)
In-Reply-To: <1574166746-27197-1-git-send-email-amit.kachhap@arm.com>
From: Kristina Martsenko <kristina.martsenko@arm.com>
As we're going to enable pointer auth within the kernel and use a
different APIAKey for the kernel itself, so move the user APIAKey
switch to EL0 exception return.
The other 4 keys could remain switched during task switch, but are also
moved to keep things consistent.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[Amit: commit msg]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
---
Changes since last version:
* Minor change in commit.
arch/arm64/include/asm/asm_pointer_auth.h | 45 +++++++++++++++++++++++++++++++
arch/arm64/include/asm/pointer_auth.h | 30 +--------------------
arch/arm64/kernel/asm-offsets.c | 11 ++++++++
arch/arm64/kernel/entry.S | 3 +++
arch/arm64/kernel/pointer_auth.c | 3 ---
arch/arm64/kernel/process.c | 1 -
6 files changed, 60 insertions(+), 33 deletions(-)
create mode 100644 arch/arm64/include/asm/asm_pointer_auth.h
diff --git a/arch/arm64/include/asm/asm_pointer_auth.h b/arch/arm64/include/asm/asm_pointer_auth.h
new file mode 100644
index 0000000..cb21a06
--- /dev/null
+++ b/arch/arm64/include/asm/asm_pointer_auth.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_ASM_POINTER_AUTH_H
+#define __ASM_ASM_POINTER_AUTH_H
+
+#include <asm/alternative.h>
+#include <asm/asm-offsets.h>
+#include <asm/cpufeature.h>
+#include <asm/sysreg.h>
+
+#ifdef CONFIG_ARM64_PTR_AUTH
+
+ .macro ptrauth_keys_install_user tsk, tmp1, tmp2, tmp3
+ mov \tmp1, #THREAD_KEYS_USER
+ add \tmp1, \tsk, \tmp1
+alternative_if_not ARM64_HAS_ADDRESS_AUTH
+ b .Laddr_auth_skip_\@
+alternative_else_nop_endif
+ ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_KEY_APIA]
+ msr_s SYS_APIAKEYLO_EL1, \tmp2
+ msr_s SYS_APIAKEYHI_EL1, \tmp3
+ ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_KEY_APIB]
+ msr_s SYS_APIBKEYLO_EL1, \tmp2
+ msr_s SYS_APIBKEYHI_EL1, \tmp3
+ ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_KEY_APDA]
+ msr_s SYS_APDAKEYLO_EL1, \tmp2
+ msr_s SYS_APDAKEYHI_EL1, \tmp3
+ ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_KEY_APDB]
+ msr_s SYS_APDBKEYLO_EL1, \tmp2
+ msr_s SYS_APDBKEYHI_EL1, \tmp3
+.Laddr_auth_skip_\@:
+alternative_if ARM64_HAS_GENERIC_AUTH
+ ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_KEY_APGA]
+ msr_s SYS_APGAKEYLO_EL1, \tmp2
+ msr_s SYS_APGAKEYHI_EL1, \tmp3
+alternative_else_nop_endif
+ .endm
+
+#else /* CONFIG_ARM64_PTR_AUTH */
+
+ .macro ptrauth_keys_install_user tsk, tmp1, tmp2, tmp3
+ .endm
+
+#endif /* CONFIG_ARM64_PTR_AUTH */
+
+#endif /* __ASM_ASM_POINTER_AUTH_H */
diff --git a/arch/arm64/include/asm/pointer_auth.h b/arch/arm64/include/asm/pointer_auth.h
index 7a24bad..21c2115 100644
--- a/arch/arm64/include/asm/pointer_auth.h
+++ b/arch/arm64/include/asm/pointer_auth.h
@@ -43,26 +43,6 @@ static inline void ptrauth_keys_init(struct ptrauth_keys *keys)
get_random_bytes(&keys->apga, sizeof(keys->apga));
}
-#define __ptrauth_key_install(k, v) \
-do { \
- struct ptrauth_key __pki_v = (v); \
- write_sysreg_s(__pki_v.lo, SYS_ ## k ## KEYLO_EL1); \
- write_sysreg_s(__pki_v.hi, SYS_ ## k ## KEYHI_EL1); \
-} while (0)
-
-static inline void ptrauth_keys_switch(struct ptrauth_keys *keys)
-{
- if (system_supports_address_auth()) {
- __ptrauth_key_install(APIA, keys->apia);
- __ptrauth_key_install(APIB, keys->apib);
- __ptrauth_key_install(APDA, keys->apda);
- __ptrauth_key_install(APDB, keys->apdb);
- }
-
- if (system_supports_generic_auth())
- __ptrauth_key_install(APGA, keys->apga);
-}
-
extern int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg);
/*
@@ -78,20 +58,12 @@ static inline unsigned long ptrauth_strip_insn_pac(unsigned long ptr)
}
#define ptrauth_thread_init_user(tsk) \
-do { \
- struct task_struct *__ptiu_tsk = (tsk); \
- ptrauth_keys_init(&__ptiu_tsk->thread.keys_user); \
- ptrauth_keys_switch(&__ptiu_tsk->thread.keys_user); \
-} while (0)
-
-#define ptrauth_thread_switch(tsk) \
- ptrauth_keys_switch(&(tsk)->thread.keys_user)
+ ptrauth_keys_init(&(tsk)->thread.keys_user)
#else /* CONFIG_ARM64_PTR_AUTH */
#define ptrauth_prctl_reset_keys(tsk, arg) (-EINVAL)
#define ptrauth_strip_insn_pac(lr) (lr)
#define ptrauth_thread_init_user(tsk)
-#define ptrauth_thread_switch(tsk)
#endif /* CONFIG_ARM64_PTR_AUTH */
#endif /* __ASM_POINTER_AUTH_H */
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index 2146857..ef0c24b 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -40,6 +40,9 @@ int main(void)
#endif
BLANK();
DEFINE(THREAD_CPU_CONTEXT, offsetof(struct task_struct, thread.cpu_context));
+#ifdef CONFIG_ARM64_PTR_AUTH
+ DEFINE(THREAD_KEYS_USER, offsetof(struct task_struct, thread.keys_user));
+#endif
BLANK();
DEFINE(S_X0, offsetof(struct pt_regs, regs[0]));
DEFINE(S_X2, offsetof(struct pt_regs, regs[2]));
@@ -127,5 +130,13 @@ int main(void)
DEFINE(SDEI_EVENT_INTREGS, offsetof(struct sdei_registered_event, interrupted_regs));
DEFINE(SDEI_EVENT_PRIORITY, offsetof(struct sdei_registered_event, priority));
#endif
+#ifdef CONFIG_ARM64_PTR_AUTH
+ DEFINE(PTRAUTH_KEY_APIA, offsetof(struct ptrauth_keys, apia));
+ DEFINE(PTRAUTH_KEY_APIB, offsetof(struct ptrauth_keys, apib));
+ DEFINE(PTRAUTH_KEY_APDA, offsetof(struct ptrauth_keys, apda));
+ DEFINE(PTRAUTH_KEY_APDB, offsetof(struct ptrauth_keys, apdb));
+ DEFINE(PTRAUTH_KEY_APGA, offsetof(struct ptrauth_keys, apga));
+ BLANK();
+#endif
return 0;
}
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index cf3bd29..6a4e402 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -14,6 +14,7 @@
#include <asm/alternative.h>
#include <asm/assembler.h>
#include <asm/asm-offsets.h>
+#include <asm/asm_pointer_auth.h>
#include <asm/cpufeature.h>
#include <asm/errno.h>
#include <asm/esr.h>
@@ -341,6 +342,8 @@ alternative_else_nop_endif
msr cntkctl_el1, x1
4:
#endif
+ ptrauth_keys_install_user tsk, x0, x1, x2
+
apply_ssbd 0, x0, x1
.endif
diff --git a/arch/arm64/kernel/pointer_auth.c b/arch/arm64/kernel/pointer_auth.c
index c507b58..95985be 100644
--- a/arch/arm64/kernel/pointer_auth.c
+++ b/arch/arm64/kernel/pointer_auth.c
@@ -19,7 +19,6 @@ int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg)
if (!arg) {
ptrauth_keys_init(keys);
- ptrauth_keys_switch(keys);
return 0;
}
@@ -41,7 +40,5 @@ int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg)
if (arg & PR_PAC_APGAKEY)
get_random_bytes(&keys->apga, sizeof(keys->apga));
- ptrauth_keys_switch(keys);
-
return 0;
}
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 71f788c..3716528 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -505,7 +505,6 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev,
contextidr_thread_switch(next);
entry_task_switch(next);
uao_thread_switch(next);
- ptrauth_thread_switch(next);
ssbs_thread_switch(next);
/*
--
2.7.4
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next prev parent reply other threads:[~2019-11-19 12:33 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-19 12:32 [PATCH v2 00/14] arm64: return address signing Amit Daniel Kachhap
2019-11-19 12:32 ` [PATCH v2 01/14] arm64: cpufeature: add pointer auth meta-capabilities Amit Daniel Kachhap
2019-11-19 12:32 ` Amit Daniel Kachhap [this message]
2019-11-19 12:32 ` [PATCH v2 03/14] arm64: create macro to park cpu in an infinite loop Amit Daniel Kachhap
2019-11-19 12:32 ` [PATCH v2 04/14] arm64: ptrauth: Add bootup/runtime flags for __cpu_setup Amit Daniel Kachhap
2019-11-19 12:32 ` [PATCH v2 05/14] arm64: enable ptrauth earlier Amit Daniel Kachhap
2019-11-19 12:32 ` [PATCH v2 06/14] arm64: rename ptrauth key structures to be user-specific Amit Daniel Kachhap
2019-11-22 13:28 ` Ard Biesheuvel
2019-11-25 9:22 ` Amit Kachhap
2019-11-19 12:32 ` [PATCH v2 07/14] arm64: initialize and switch ptrauth kernel keys Amit Daniel Kachhap
2019-11-22 19:19 ` Richard Henderson
2019-11-25 9:34 ` Amit Kachhap
2019-11-25 9:39 ` Ard Biesheuvel
2019-11-25 11:01 ` Amit Kachhap
2019-11-19 12:32 ` [PATCH v2 08/14] arm64: mask PAC bits of __builtin_return_address Amit Daniel Kachhap
2019-11-21 17:42 ` Ard Biesheuvel
2019-11-22 8:48 ` Richard Henderson
2019-11-22 13:27 ` Ard Biesheuvel
2019-11-25 9:18 ` Amit Kachhap
2019-11-25 9:12 ` Amit Kachhap
2019-11-25 5:42 ` Amit Kachhap
2019-11-19 12:32 ` [PATCH v2 09/14] arm64: unwind: strip PAC from kernel addresses Amit Daniel Kachhap
2019-11-19 12:32 ` [PATCH v2 10/14] arm64: __show_regs: strip PAC from lr in printk Amit Daniel Kachhap
2019-11-19 12:32 ` [PATCH v2 11/14] arm64: suspend: restore the kernel ptrauth keys Amit Daniel Kachhap
2019-11-19 12:32 ` [PATCH v2 12/14] arm64: kprobe: disable probe of ptrauth instruction Amit Daniel Kachhap
2019-11-19 12:32 ` [PATCH v2 13/14] arm64: compile the kernel with ptrauth return address signing Amit Daniel Kachhap
2019-11-21 15:06 ` Mark Brown
2019-11-26 7:00 ` Amit Kachhap
2019-11-25 17:35 ` Mark Brown
2019-11-19 12:32 ` [PATCH v2 14/14] lkdtm: arm64: test kernel pointer authentication Amit Daniel Kachhap
2019-11-21 17:39 ` Ard Biesheuvel
2019-11-22 18:51 ` Richard Henderson
2019-11-25 9:25 ` Amit Kachhap
2019-11-25 5:34 ` Amit Kachhap
2019-11-20 16:05 ` [PATCH v2 00/14] arm64: return address signing Ard Biesheuvel
2019-11-21 12:15 ` Amit Kachhap
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