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| author | Zong Li <zong.li@sifive.com> | 2020-03-10 00:55:44 +0800 |
|---|---|---|
| committer | Palmer Dabbelt <palmerdabbelt@google.com> | 2020-03-26 09:24:55 -0700 |
| commit | 8fdddb2eae731dd6beb89f9b812e5915d1beb744 (patch) | |
| tree | 698aa44a6e112eb6a8fa5a695097f798c54cd2d0 /arch/riscv/kernel | |
| parent | 043cb41a85de1c0e944da61ad7a264960e22c865 (diff) | |
| download | linux-8fdddb2eae731dd6beb89f9b812e5915d1beb744.tar.bz2 | |
riscv: patch code by fixmap mapping
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>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Diffstat (limited to 'arch/riscv/kernel')
| -rw-r--r-- | arch/riscv/kernel/ftrace.c | 13 |
1 files 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; } |