From: guoren@kernel.org
To: linux-csky@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
arnd@arndb.de, Mao Han <han_mao@c-sky.com>,
Guo Ren <guoren@kernel.org>
Subject: [PATCH 2/5] csky: Initial stack protector support
Date: Mon, 30 Dec 2019 16:23:28 +0800 [thread overview]
Message-ID: <20191230082331.30976-2-guoren@kernel.org> (raw)
In-Reply-To: <20191230082331.30976-1-guoren@kernel.org>
From: Mao Han <han_mao@c-sky.com>
This is a basic -fstack-protector support without per-task canary
switching. The protector will report something like when stack
corruption is detected:
It's tested with strcpy local array overflow in sys_kill and get:
stack-protector: Kernel stack is corrupted in: sys_kill+0x23c/0x23c
TODO:
- Support task switch for different cannary
Signed-off-by: Mao Han <han_mao@c-sky.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
---
arch/csky/Kconfig | 1 +
arch/csky/include/asm/stackprotector.h | 29 ++++++++++++++++++++++++++
arch/csky/kernel/process.c | 6 ++++++
3 files changed, 36 insertions(+)
create mode 100644 arch/csky/include/asm/stackprotector.h
diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
index 3973847b5f42..285234300740 100644
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig
@@ -48,6 +48,7 @@ config CSKY
select HAVE_PERF_USER_STACK_DUMP
select HAVE_DMA_API_DEBUG
select HAVE_DMA_CONTIGUOUS
+ select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
select MAY_HAVE_SPARSE_IRQ
select MODULES_USE_ELF_RELA if MODULES
diff --git a/arch/csky/include/asm/stackprotector.h b/arch/csky/include/asm/stackprotector.h
new file mode 100644
index 000000000000..d7cd4e51edd9
--- /dev/null
+++ b/arch/csky/include/asm/stackprotector.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_STACKPROTECTOR_H
+#define _ASM_STACKPROTECTOR_H 1
+
+#include <linux/random.h>
+#include <linux/version.h>
+
+extern unsigned long __stack_chk_guard;
+
+/*
+ * Initialize the stackprotector canary value.
+ *
+ * NOTE: this must only be called from functions that never return,
+ * and it must always be inlined.
+ */
+static __always_inline void boot_init_stack_canary(void)
+{
+ unsigned long canary;
+
+ /* Try to get a semi random initial value. */
+ get_random_bytes(&canary, sizeof(canary));
+ canary ^= LINUX_VERSION_CODE;
+ canary &= CANARY_MASK;
+
+ current->stack_canary = canary;
+ __stack_chk_guard = current->stack_canary;
+}
+
+#endif /* __ASM_SH_STACKPROTECTOR_H */
diff --git a/arch/csky/kernel/process.c b/arch/csky/kernel/process.c
index f320d9248a22..5349cd8c0f30 100644
--- a/arch/csky/kernel/process.c
+++ b/arch/csky/kernel/process.c
@@ -16,6 +16,12 @@
struct cpuinfo_csky cpu_data[NR_CPUS];
+#ifdef CONFIG_STACKPROTECTOR
+#include <linux/stackprotector.h>
+unsigned long __stack_chk_guard __read_mostly;
+EXPORT_SYMBOL(__stack_chk_guard);
+#endif
+
asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);
--
2.17.0
next prev parent reply other threads:[~2019-12-30 8:24 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-30 8:23 [PATCH 1/5] MAINTAINERS: csky: Add mailing list for csky guoren
2019-12-30 8:23 ` guoren [this message]
2019-12-30 8:23 ` [PATCH 3/5] csky: Tightly-Coupled Memory or Sram support guoren
2019-12-30 8:23 ` [PATCH 4/5] csky: Separate fixaddr_init from highmem guoren
2019-12-30 8:23 ` [PATCH 5/5] csky/mm: Fixup export invalid_pte_table symbol guoren
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