[PATCH V2] LoongArch: Adjust {copy, clear}_user exception handler behavior
From: Weihao Li
Date: Wed Aug 30 2023 - 23:38:14 EST
The {copy, clear}_user function should returns number of bytes that could
not be {copied, cleared}. So, try to {copy, clear} byte by byte when
ld.{d,w,h} and st.{d,w,h} trapped into an exception.
Signed-off-by: Weihao Li <liweihao@xxxxxxxxxxx>
Reviewed-by: WANG Rui <wangrui@xxxxxxxxxxx>
Reviewed-by: Huacai Chen <chenhuacai@xxxxxxxxxx>
---
v2:
- Fix jump target error in __clear_user_fast
- Adjust commit message and email format
arch/loongarch/lib/clear_user.S | 87 ++++++++---------
arch/loongarch/lib/copy_user.S | 161 ++++++++++++++++----------------
2 files changed, 127 insertions(+), 121 deletions(-)
diff --git a/arch/loongarch/lib/clear_user.S b/arch/loongarch/lib/clear_user.S
index 0790eadce166..be741544e62b 100644
--- a/arch/loongarch/lib/clear_user.S
+++ b/arch/loongarch/lib/clear_user.S
@@ -11,19 +11,6 @@
#include <asm/cpu.h>
#include <asm/regdef.h>
-.irp to, 0, 1, 2, 3, 4, 5, 6, 7
-.L_fixup_handle_\to\():
- sub.d a0, a2, a0
- addi.d a0, a0, (\to) * (-8)
- jr ra
-.endr
-
-.irp to, 0, 2, 4
-.L_fixup_handle_s\to\():
- addi.d a0, a1, -\to
- jr ra
-.endr
-
SYM_FUNC_START(__clear_user)
/*
* Some CPUs support hardware unaligned access
@@ -51,7 +38,7 @@ SYM_FUNC_START(__clear_user_generic)
2: move a0, a1
jr ra
- _asm_extable 1b, .L_fixup_handle_s0
+ _asm_extable 1b, 2b
SYM_FUNC_END(__clear_user_generic)
/*
@@ -173,33 +160,47 @@ SYM_FUNC_START(__clear_user_fast)
jr ra
/* fixup and ex_table */
- _asm_extable 0b, .L_fixup_handle_0
- _asm_extable 1b, .L_fixup_handle_0
- _asm_extable 2b, .L_fixup_handle_1
- _asm_extable 3b, .L_fixup_handle_2
- _asm_extable 4b, .L_fixup_handle_3
- _asm_extable 5b, .L_fixup_handle_4
- _asm_extable 6b, .L_fixup_handle_5
- _asm_extable 7b, .L_fixup_handle_6
- _asm_extable 8b, .L_fixup_handle_7
- _asm_extable 9b, .L_fixup_handle_0
- _asm_extable 10b, .L_fixup_handle_1
- _asm_extable 11b, .L_fixup_handle_2
- _asm_extable 12b, .L_fixup_handle_3
- _asm_extable 13b, .L_fixup_handle_0
- _asm_extable 14b, .L_fixup_handle_1
- _asm_extable 15b, .L_fixup_handle_0
- _asm_extable 16b, .L_fixup_handle_0
- _asm_extable 17b, .L_fixup_handle_s0
- _asm_extable 18b, .L_fixup_handle_s0
- _asm_extable 19b, .L_fixup_handle_s0
- _asm_extable 20b, .L_fixup_handle_s2
- _asm_extable 21b, .L_fixup_handle_s0
- _asm_extable 22b, .L_fixup_handle_s0
- _asm_extable 23b, .L_fixup_handle_s4
- _asm_extable 24b, .L_fixup_handle_s0
- _asm_extable 25b, .L_fixup_handle_s4
- _asm_extable 26b, .L_fixup_handle_s0
- _asm_extable 27b, .L_fixup_handle_s4
- _asm_extable 28b, .L_fixup_handle_s0
+.Llarge_fixup:
+ sub.d a1, a2, a0
+
+.Lsmall_fixup:
+29: st.b zero, a0, 0
+ addi.d a0, a0, 1
+ addi.d a1, a1, -1
+ bgt a1, zero, 29b
+
+.Lexit:
+ move a0, a1
+ jr ra
+
+ _asm_extable 0b, .Lsmall_fixup
+ _asm_extable 1b, .Llarge_fixup
+ _asm_extable 2b, .Llarge_fixup
+ _asm_extable 3b, .Llarge_fixup
+ _asm_extable 4b, .Llarge_fixup
+ _asm_extable 5b, .Llarge_fixup
+ _asm_extable 6b, .Llarge_fixup
+ _asm_extable 7b, .Llarge_fixup
+ _asm_extable 8b, .Llarge_fixup
+ _asm_extable 9b, .Llarge_fixup
+ _asm_extable 10b, .Llarge_fixup
+ _asm_extable 11b, .Llarge_fixup
+ _asm_extable 12b, .Llarge_fixup
+ _asm_extable 13b, .Llarge_fixup
+ _asm_extable 14b, .Llarge_fixup
+ _asm_extable 15b, .Llarge_fixup
+ _asm_extable 16b, .Llarge_fixup
+ _asm_extable 17b, .Lexit
+ _asm_extable 18b, .Lsmall_fixup
+ _asm_extable 19b, .Lsmall_fixup
+ _asm_extable 20b, .Lsmall_fixup
+ _asm_extable 21b, .Lsmall_fixup
+ _asm_extable 22b, .Lsmall_fixup
+ _asm_extable 23b, .Lsmall_fixup
+ _asm_extable 24b, .Lsmall_fixup
+ _asm_extable 25b, .Lsmall_fixup
+ _asm_extable 26b, .Lsmall_fixup
+ _asm_extable 27b, .Lsmall_fixup
+ _asm_extable 28b, .Lsmall_fixup
+ _asm_extable 29b, .Lexit
SYM_FUNC_END(__clear_user_fast)
diff --git a/arch/loongarch/lib/copy_user.S b/arch/loongarch/lib/copy_user.S
index bfe3d2793d00..feec3d362803 100644
--- a/arch/loongarch/lib/copy_user.S
+++ b/arch/loongarch/lib/copy_user.S
@@ -11,19 +11,6 @@
#include <asm/cpu.h>
#include <asm/regdef.h>
-.irp to, 0, 1, 2, 3, 4, 5, 6, 7
-.L_fixup_handle_\to\():
- sub.d a0, a2, a0
- addi.d a0, a0, (\to) * (-8)
- jr ra
-.endr
-
-.irp to, 0, 2, 4
-.L_fixup_handle_s\to\():
- addi.d a0, a2, -\to
- jr ra
-.endr
-
SYM_FUNC_START(__copy_user)
/*
* Some CPUs support hardware unaligned access
@@ -54,8 +41,8 @@ SYM_FUNC_START(__copy_user_generic)
3: move a0, a2
jr ra
- _asm_extable 1b, .L_fixup_handle_s0
- _asm_extable 2b, .L_fixup_handle_s0
+ _asm_extable 1b, 3b
+ _asm_extable 2b, 3b
SYM_FUNC_END(__copy_user_generic)
/*
@@ -69,10 +56,10 @@ SYM_FUNC_START(__copy_user_fast)
sltui t0, a2, 9
bnez t0, .Lsmall
- add.d a3, a1, a2
- add.d a2, a0, a2
0: ld.d t0, a1, 0
1: st.d t0, a0, 0
+ add.d a3, a1, a2
+ add.d a2, a0, a2
/* align up destination address */
andi t1, a0, 7
@@ -94,7 +81,6 @@ SYM_FUNC_START(__copy_user_fast)
7: ld.d t5, a1, 40
8: ld.d t6, a1, 48
9: ld.d t7, a1, 56
- addi.d a1, a1, 64
10: st.d t0, a0, 0
11: st.d t1, a0, 8
12: st.d t2, a0, 16
@@ -103,6 +89,7 @@ SYM_FUNC_START(__copy_user_fast)
15: st.d t5, a0, 40
16: st.d t6, a0, 48
17: st.d t7, a0, 56
+ addi.d a1, a1, 64
addi.d a0, a0, 64
bltu a1, a4, .Lloop64
@@ -114,11 +101,11 @@ SYM_FUNC_START(__copy_user_fast)
19: ld.d t1, a1, 8
20: ld.d t2, a1, 16
21: ld.d t3, a1, 24
- addi.d a1, a1, 32
22: st.d t0, a0, 0
23: st.d t1, a0, 8
24: st.d t2, a0, 16
25: st.d t3, a0, 24
+ addi.d a1, a1, 32
addi.d a0, a0, 32
.Llt32:
@@ -126,9 +113,9 @@ SYM_FUNC_START(__copy_user_fast)
bgeu a1, a4, .Llt16
26: ld.d t0, a1, 0
27: ld.d t1, a1, 8
- addi.d a1, a1, 16
28: st.d t0, a0, 0
29: st.d t1, a0, 8
+ addi.d a1, a1, 16
addi.d a0, a0, 16
.Llt16:
@@ -136,6 +123,7 @@ SYM_FUNC_START(__copy_user_fast)
bgeu a1, a4, .Llt8
30: ld.d t0, a1, 0
31: st.d t0, a0, 0
+ addi.d a1, a1, 8
addi.d a0, a0, 8
.Llt8:
@@ -214,62 +202,79 @@ SYM_FUNC_START(__copy_user_fast)
jr ra
/* fixup and ex_table */
- _asm_extable 0b, .L_fixup_handle_0
- _asm_extable 1b, .L_fixup_handle_0
- _asm_extable 2b, .L_fixup_handle_0
- _asm_extable 3b, .L_fixup_handle_0
- _asm_extable 4b, .L_fixup_handle_0
- _asm_extable 5b, .L_fixup_handle_0
- _asm_extable 6b, .L_fixup_handle_0
- _asm_extable 7b, .L_fixup_handle_0
- _asm_extable 8b, .L_fixup_handle_0
- _asm_extable 9b, .L_fixup_handle_0
- _asm_extable 10b, .L_fixup_handle_0
- _asm_extable 11b, .L_fixup_handle_1
- _asm_extable 12b, .L_fixup_handle_2
- _asm_extable 13b, .L_fixup_handle_3
- _asm_extable 14b, .L_fixup_handle_4
- _asm_extable 15b, .L_fixup_handle_5
- _asm_extable 16b, .L_fixup_handle_6
- _asm_extable 17b, .L_fixup_handle_7
- _asm_extable 18b, .L_fixup_handle_0
- _asm_extable 19b, .L_fixup_handle_0
- _asm_extable 20b, .L_fixup_handle_0
- _asm_extable 21b, .L_fixup_handle_0
- _asm_extable 22b, .L_fixup_handle_0
- _asm_extable 23b, .L_fixup_handle_1
- _asm_extable 24b, .L_fixup_handle_2
- _asm_extable 25b, .L_fixup_handle_3
- _asm_extable 26b, .L_fixup_handle_0
- _asm_extable 27b, .L_fixup_handle_0
- _asm_extable 28b, .L_fixup_handle_0
- _asm_extable 29b, .L_fixup_handle_1
- _asm_extable 30b, .L_fixup_handle_0
- _asm_extable 31b, .L_fixup_handle_0
- _asm_extable 32b, .L_fixup_handle_0
- _asm_extable 33b, .L_fixup_handle_0
- _asm_extable 34b, .L_fixup_handle_s0
- _asm_extable 35b, .L_fixup_handle_s0
- _asm_extable 36b, .L_fixup_handle_s0
- _asm_extable 37b, .L_fixup_handle_s0
- _asm_extable 38b, .L_fixup_handle_s0
- _asm_extable 39b, .L_fixup_handle_s0
- _asm_extable 40b, .L_fixup_handle_s0
- _asm_extable 41b, .L_fixup_handle_s2
- _asm_extable 42b, .L_fixup_handle_s0
- _asm_extable 43b, .L_fixup_handle_s0
- _asm_extable 44b, .L_fixup_handle_s0
- _asm_extable 45b, .L_fixup_handle_s0
- _asm_extable 46b, .L_fixup_handle_s0
- _asm_extable 47b, .L_fixup_handle_s4
- _asm_extable 48b, .L_fixup_handle_s0
- _asm_extable 49b, .L_fixup_handle_s0
- _asm_extable 50b, .L_fixup_handle_s0
- _asm_extable 51b, .L_fixup_handle_s4
- _asm_extable 52b, .L_fixup_handle_s0
- _asm_extable 53b, .L_fixup_handle_s0
- _asm_extable 54b, .L_fixup_handle_s0
- _asm_extable 55b, .L_fixup_handle_s4
- _asm_extable 56b, .L_fixup_handle_s0
- _asm_extable 57b, .L_fixup_handle_s0
+.Llarge_fixup:
+ sub.d a2, a2, a0
+
+.Lsmall_fixup:
+58: ld.b t0, a1, 0
+59: st.b t0, a0, 0
+ addi.d a0, a0, 1
+ addi.d a1, a1, 1
+ addi.d a2, a2, -1
+ bgt a2, zero, 58b
+
+.Lexit:
+ move a0, a2
+ jr ra
+
+ _asm_extable 0b, .Lsmall_fixup
+ _asm_extable 1b, .Lsmall_fixup
+ _asm_extable 2b, .Llarge_fixup
+ _asm_extable 3b, .Llarge_fixup
+ _asm_extable 4b, .Llarge_fixup
+ _asm_extable 5b, .Llarge_fixup
+ _asm_extable 6b, .Llarge_fixup
+ _asm_extable 7b, .Llarge_fixup
+ _asm_extable 8b, .Llarge_fixup
+ _asm_extable 9b, .Llarge_fixup
+ _asm_extable 10b, .Llarge_fixup
+ _asm_extable 11b, .Llarge_fixup
+ _asm_extable 12b, .Llarge_fixup
+ _asm_extable 13b, .Llarge_fixup
+ _asm_extable 14b, .Llarge_fixup
+ _asm_extable 15b, .Llarge_fixup
+ _asm_extable 16b, .Llarge_fixup
+ _asm_extable 17b, .Llarge_fixup
+ _asm_extable 18b, .Llarge_fixup
+ _asm_extable 19b, .Llarge_fixup
+ _asm_extable 20b, .Llarge_fixup
+ _asm_extable 21b, .Llarge_fixup
+ _asm_extable 22b, .Llarge_fixup
+ _asm_extable 23b, .Llarge_fixup
+ _asm_extable 24b, .Llarge_fixup
+ _asm_extable 25b, .Llarge_fixup
+ _asm_extable 26b, .Llarge_fixup
+ _asm_extable 27b, .Llarge_fixup
+ _asm_extable 28b, .Llarge_fixup
+ _asm_extable 29b, .Llarge_fixup
+ _asm_extable 30b, .Llarge_fixup
+ _asm_extable 31b, .Llarge_fixup
+ _asm_extable 32b, .Llarge_fixup
+ _asm_extable 33b, .Llarge_fixup
+ _asm_extable 34b, .Lexit
+ _asm_extable 35b, .Lexit
+ _asm_extable 36b, .Lsmall_fixup
+ _asm_extable 37b, .Lsmall_fixup
+ _asm_extable 38b, .Lsmall_fixup
+ _asm_extable 39b, .Lsmall_fixup
+ _asm_extable 40b, .Lsmall_fixup
+ _asm_extable 41b, .Lsmall_fixup
+ _asm_extable 42b, .Lsmall_fixup
+ _asm_extable 43b, .Lsmall_fixup
+ _asm_extable 44b, .Lsmall_fixup
+ _asm_extable 45b, .Lsmall_fixup
+ _asm_extable 46b, .Lsmall_fixup
+ _asm_extable 47b, .Lsmall_fixup
+ _asm_extable 48b, .Lsmall_fixup
+ _asm_extable 49b, .Lsmall_fixup
+ _asm_extable 50b, .Lsmall_fixup
+ _asm_extable 51b, .Lsmall_fixup
+ _asm_extable 52b, .Lsmall_fixup
+ _asm_extable 53b, .Lsmall_fixup
+ _asm_extable 54b, .Lsmall_fixup
+ _asm_extable 55b, .Lsmall_fixup
+ _asm_extable 56b, .Lsmall_fixup
+ _asm_extable 57b, .Lsmall_fixup
+ _asm_extable 58b, .Lexit
+ _asm_extable 59b, .Lexit
SYM_FUNC_END(__copy_user_fast)
--
2.39.2