On 2021/10/20 22:06, Jisheng Zhang wrote:
From: Jisheng Zhang <jszhang@xxxxxxxxxx>
Consolidate all the __ex_table constuction code with a _ASM_EXTABLE
helper.
There should be no functional change as a result of this patch.
Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
---
arch/riscv/include/asm/futex.h | 12 +++-------
arch/riscv/include/asm/uaccess.h | 40 +++++++++++---------------------
2 files changed, 17 insertions(+), 35 deletions(-)
diff --git a/arch/riscv/include/asm/futex.h b/arch/riscv/include/asm/futex.h
index 1b00badb9f87..3191574e135c 100644
--- a/arch/riscv/include/asm/futex.h
+++ b/arch/riscv/include/asm/futex.h
@@ -30,10 +30,7 @@
"3: li %[r],%[e] \n" \
" jump 2b,%[t] \n" \
" .previous \n" \
- " .section __ex_table,\"a\" \n" \
- " .balign " RISCV_SZPTR " \n" \
- " " RISCV_PTR " 1b, 3b \n" \
- " .previous \n" \
+ _ASM_EXTABLE(1b, 3b) \
: [r] "+r" (ret), [ov] "=&r" (oldval), \
[u] "+m" (*uaddr), [t] "=&r" (tmp) \
: [op] "Jr" (oparg), [e] "i" (-EFAULT) \
@@ -103,11 +100,8 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
"4: li %[r],%[e] \n"
" jump 3b,%[t] \n"
" .previous \n"
- " .section __ex_table,\"a\" \n"
- " .balign " RISCV_SZPTR " \n"
- " " RISCV_PTR " 1b, 4b \n"
- " " RISCV_PTR " 2b, 4b \n"
- " .previous \n"
+ _ASM_EXTABLE(1b, 4b) \
+ _ASM_EXTABLE(2b, 4b) \
: [r] "+r" (ret), [v] "=&r" (val), [u] "+m" (*uaddr), [t] "=&r" (tmp)
: [ov] "Jr" (oldval), [nv] "Jr" (newval), [e] "i" (-EFAULT)
: "memory");
diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h
index f314ff44c48d..35802e72ace8 100644
--- a/arch/riscv/include/asm/uaccess.h
+++ b/arch/riscv/include/asm/uaccess.h
@@ -10,6 +10,12 @@
#include <asm/pgtable.h> /* for TASK_SIZE */
+#define _ASM_EXTABLE(from, to) \
+ " .pushsection __ex_table, \"a\"\n" \
+ " .balign " RISCV_SZPTR " \n" \
+ " " RISCV_PTR "(" #from "), (" #to ")\n" \
+ " .popsection\n"
+
The jump_label mechanism could use this macro too,
see arch/riscv/include/asm/jump_label.h, maybe move the above into asm.h
and also do some replace in next patch ?
Question: the jump label use relative address, but why not trigger the
Section mismatch issue?
