From: Zong Li <zong.li@sifive.com>
To: palmer@dabbelt.com, paul.walmsley@sifive.com,
aou@eecs.berkeley.edu, linux-riscv@lists.infradead.org,
linux-kernel@vger.kernel.org
Cc: Zong Li <zong.li@sifive.com>
Subject: [PATCH v2 9/9] riscv: patch code by fixmap mapping
Date: Mon, 9 Mar 2020 16:22:29 +0800 [thread overview]
Message-ID: <4e0f705ad808e9e0ec2db346c548dd2c5522e109.1583741997.git.zong.li@sifive.com> (raw)
In-Reply-To: <cover.1583741997.git.zong.li@sifive.com>
On strict kernel memory permission, the ftrace have to change the
permission of text for dynamic patching the intructions. Use
riscv_patch_text_nosync() to patch code instead of probe_kernel_write.
Signed-off-by: Zong Li <zong.li@sifive.com>
---
arch/riscv/kernel/ftrace.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c
index c40fdcdeb950..ce69b34ff55d 100644
--- a/arch/riscv/kernel/ftrace.c
+++ b/arch/riscv/kernel/ftrace.c
@@ -8,6 +8,7 @@
#include <linux/ftrace.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
+#include <asm/patch.h>
#ifdef CONFIG_DYNAMIC_FTRACE
static int ftrace_check_current_call(unsigned long hook_pos,
@@ -46,20 +47,14 @@ static int __ftrace_modify_call(unsigned long hook_pos, unsigned long target,
{
unsigned int call[2];
unsigned int nops[2] = {NOP4, NOP4};
- int ret = 0;
make_call(hook_pos, target, call);
- /* replace the auipc-jalr pair at once */
- ret = probe_kernel_write((void *)hook_pos, enable ? call : nops,
- MCOUNT_INSN_SIZE);
- /* return must be -EPERM on write error */
- if (ret)
+ /* Replace the auipc-jalr pair at once. Return -EPERM on write error. */
+ if (riscv_patch_text_nosync
+ ((void *)hook_pos, enable ? call : nops, MCOUNT_INSN_SIZE))
return -EPERM;
- smp_mb();
- flush_icache_range((void *)hook_pos, (void *)hook_pos + MCOUNT_INSN_SIZE);
-
return 0;
}
--
2.25.1
next prev parent reply other threads:[~2020-03-09 8:23 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-09 8:22 [PATCH v2 0/9] Support strict kernel memory permissions for security Zong Li
2020-03-09 8:22 ` [PATCH v2 1/9] riscv: add ARCH_HAS_SET_MEMORY support Zong Li
2020-03-09 12:50 ` kbuild test robot
2020-03-09 8:22 ` [PATCH v2 2/9] riscv: add ARCH_HAS_SET_DIRECT_MAP support Zong Li
2020-03-09 8:22 ` [PATCH v2 3/9] riscv: add ARCH_SUPPORTS_DEBUG_PAGEALLOC support Zong Li
2020-03-09 8:22 ` [PATCH v2 4/9] riscv: move exception table immediately after RO_DATA Zong Li
2020-03-09 8:22 ` [PATCH v2 5/9] riscv: add alignment for text, rodata and data sections Zong Li
2020-03-09 8:22 ` [PATCH v2 6/9] riscv: add STRICT_KERNEL_RWX support Zong Li
2020-03-09 13:13 ` kbuild test robot
2020-03-09 8:22 ` [PATCH v2 7/9] riscv: add macro to get instruction length Zong Li
2020-03-09 8:22 ` [PATCH v2 8/9] riscv: introduce interfaces to patch kernel code Zong Li
2020-03-09 12:49 ` kbuild test robot
2020-03-09 13:12 ` kbuild test robot
2020-03-09 8:22 ` Zong Li [this message]
2020-03-09 8:33 ` [PATCH v2 0/9] Support strict kernel memory permissions for security Zong Li
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