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* [PATCH AUTOSEL 5.6 279/606] csky: Fixup msa highest 3 bits mask
       [not found] <20200608231211.3363633-1-sashal@kernel.org>
@ 2020-06-08 23:06 ` Sasha Levin
  2020-06-08 23:06 ` [PATCH AUTOSEL 5.6 280/606] csky: Fixup perf callchain unwind Sasha Levin
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 4+ messages in thread
From: Sasha Levin @ 2020-06-08 23:06 UTC (permalink / raw)
  To: linux-kernel, stable; +Cc: Liu Yibin, Guo Ren, Sasha Levin, linux-csky

From: Liu Yibin <jiulong@linux.alibaba.com>

[ Upstream commit 165f2d2858013253042809df082b8df7e34e86d7 ]

Just as comment mentioned, the msa format:

 cr<30/31, 15> MSA register format:
 31 - 29 | 28 - 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
   BA     Reserved  SH  WA  B   SO SEC  C   D   V

So we should shift 29 bits not 28 bits for mask

Signed-off-by: Liu Yibin <jiulong@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/csky/abiv1/inc/abi/entry.h | 4 ++--
 arch/csky/abiv2/inc/abi/entry.h | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/csky/abiv1/inc/abi/entry.h b/arch/csky/abiv1/inc/abi/entry.h
index 5056ebb902d1..61d94ec7dd16 100644
--- a/arch/csky/abiv1/inc/abi/entry.h
+++ b/arch/csky/abiv1/inc/abi/entry.h
@@ -167,8 +167,8 @@
 	 *   BA     Reserved  C   D   V
 	 */
 	cprcr	r6, cpcr30
-	lsri	r6, 28
-	lsli	r6, 28
+	lsri	r6, 29
+	lsli	r6, 29
 	addi	r6, 0xe
 	cpwcr	r6, cpcr30
 
diff --git a/arch/csky/abiv2/inc/abi/entry.h b/arch/csky/abiv2/inc/abi/entry.h
index 111973c6c713..9023828ede97 100644
--- a/arch/csky/abiv2/inc/abi/entry.h
+++ b/arch/csky/abiv2/inc/abi/entry.h
@@ -225,8 +225,8 @@
 	 */
 	mfcr	r6, cr<30, 15> /* Get MSA0 */
 2:
-	lsri	r6, 28
-	lsli	r6, 28
+	lsri	r6, 29
+	lsli	r6, 29
 	addi	r6, 0x1ce
 	mtcr	r6, cr<30, 15> /* Set MSA0 */
 
-- 
2.25.1


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH AUTOSEL 5.6 280/606] csky: Fixup perf callchain unwind
       [not found] <20200608231211.3363633-1-sashal@kernel.org>
  2020-06-08 23:06 ` [PATCH AUTOSEL 5.6 279/606] csky: Fixup msa highest 3 bits mask Sasha Levin
@ 2020-06-08 23:06 ` Sasha Levin
  2020-06-08 23:06 ` [PATCH AUTOSEL 5.6 281/606] csky: Fixup remove duplicate irq_disable Sasha Levin
  2020-06-08 23:06 ` [PATCH AUTOSEL 5.6 286/606] csky: Fixup raw_copy_from_user() Sasha Levin
  3 siblings, 0 replies; 4+ messages in thread
From: Sasha Levin @ 2020-06-08 23:06 UTC (permalink / raw)
  To: linux-kernel, stable; +Cc: Mao Han, Guo Ren, Sasha Levin, linux-csky

From: Mao Han <han_mao@linux.alibaba.com>

[ Upstream commit 229a0ddee1108a3f82a873e6cbbe35c92c540444 ]

 [ 5221.974084] Unable to handle kernel paging request at virtual address 0xfffff000, pc: 0x8002c18e
 [ 5221.985929] Oops: 00000000
 [ 5221.989488]
 [ 5221.989488] CURRENT PROCESS:
 [ 5221.989488]
 [ 5221.992877] COMM=callchain_test PID=11962
 [ 5221.995213] TEXT=00008000-000087e0 DATA=00009f1c-0000a018 BSS=0000a018-0000b000
 [ 5221.999037] USER-STACK=7fc18e20  KERNEL-STACK=be204680
 [ 5221.999037]
 [ 5222.003292] PC: 0x8002c18e (perf_callchain_kernel+0x3e/0xd4)
 [ 5222.007957] LR: 0x8002c198 (perf_callchain_kernel+0x48/0xd4)
 [ 5222.074873] Call Trace:
 [ 5222.074873] [<800a248e>] get_perf_callchain+0x20a/0x29c
 [ 5222.074873] [<8009d964>] perf_callchain+0x64/0x80
 [ 5222.074873] [<8009dc1c>] perf_prepare_sample+0x29c/0x4b8
 [ 5222.074873] [<8009de6e>] perf_event_output_forward+0x36/0x98
 [ 5222.074873] [<800497e0>] search_exception_tables+0x20/0x44
 [ 5222.074873] [<8002cbb6>] do_page_fault+0x92/0x378
 [ 5222.074873] [<80098608>] __perf_event_overflow+0x54/0xdc
 [ 5222.074873] [<80098778>] perf_swevent_hrtimer+0xe8/0x164
 [ 5222.074873] [<8002ddd0>] update_mmu_cache+0x0/0xd8
 [ 5222.074873] [<8002c014>] user_backtrace+0x58/0xc4
 [ 5222.074873] [<8002c0b4>] perf_callchain_user+0x34/0xd0
 [ 5222.074873] [<800a2442>] get_perf_callchain+0x1be/0x29c
 [ 5222.074873] [<8009d964>] perf_callchain+0x64/0x80
 [ 5222.074873] [<8009d834>] perf_output_sample+0x78c/0x858
 [ 5222.074873] [<8009dc1c>] perf_prepare_sample+0x29c/0x4b8
 [ 5222.074873] [<8009de94>] perf_event_output_forward+0x5c/0x98
 [ 5222.097846]
 [ 5222.097846] [<800a0300>] perf_event_exit_task+0x58/0x43c
 [ 5222.097846] [<8006c874>] hrtimer_interrupt+0x104/0x2ec
 [ 5222.097846] [<800a0300>] perf_event_exit_task+0x58/0x43c
 [ 5222.097846] [<80437bb6>] dw_apb_clockevent_irq+0x2a/0x4c
 [ 5222.097846] [<8006c770>] hrtimer_interrupt+0x0/0x2ec
 [ 5222.097846] [<8005f2e4>] __handle_irq_event_percpu+0xac/0x19c
 [ 5222.097846] [<80437bb6>] dw_apb_clockevent_irq+0x2a/0x4c
 [ 5222.097846] [<8005f408>] handle_irq_event_percpu+0x34/0x88
 [ 5222.097846] [<8005f480>] handle_irq_event+0x24/0x64
 [ 5222.097846] [<8006218c>] handle_level_irq+0x68/0xdc
 [ 5222.097846] [<8005ec76>] __handle_domain_irq+0x56/0xa8
 [ 5222.097846] [<80450e90>] ck_irq_handler+0xac/0xe4
 [ 5222.097846] [<80029012>] csky_do_IRQ+0x12/0x24
 [ 5222.097846] [<8002a3a0>] csky_irq+0x70/0x80
 [ 5222.097846] [<800ca612>] alloc_set_pte+0xd2/0x238
 [ 5222.097846] [<8002ddd0>] update_mmu_cache+0x0/0xd8
 [ 5222.097846] [<800a0340>] perf_event_exit_task+0x98/0x43c

The original fp check doesn't base on the real kernal stack region.
Invalid fp address may cause kernel panic.

Signed-off-by: Mao Han <han_mao@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/csky/kernel/perf_callchain.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/csky/kernel/perf_callchain.c b/arch/csky/kernel/perf_callchain.c
index e68ff375c8f8..ab55e98ee8f6 100644
--- a/arch/csky/kernel/perf_callchain.c
+++ b/arch/csky/kernel/perf_callchain.c
@@ -12,12 +12,17 @@ struct stackframe {
 
 static int unwind_frame_kernel(struct stackframe *frame)
 {
-	if (kstack_end((void *)frame->fp))
+	unsigned long low = (unsigned long)task_stack_page(current);
+	unsigned long high = low + THREAD_SIZE;
+
+	if (unlikely(frame->fp < low || frame->fp > high))
 		return -EPERM;
-	if (frame->fp & 0x3 || frame->fp < TASK_SIZE)
+
+	if (kstack_end((void *)frame->fp) || frame->fp & 0x3)
 		return -EPERM;
 
 	*frame = *(struct stackframe *)frame->fp;
+
 	if (__kernel_text_address(frame->lr)) {
 		int graph = 0;
 
-- 
2.25.1


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH AUTOSEL 5.6 281/606] csky: Fixup remove duplicate irq_disable
       [not found] <20200608231211.3363633-1-sashal@kernel.org>
  2020-06-08 23:06 ` [PATCH AUTOSEL 5.6 279/606] csky: Fixup msa highest 3 bits mask Sasha Levin
  2020-06-08 23:06 ` [PATCH AUTOSEL 5.6 280/606] csky: Fixup perf callchain unwind Sasha Levin
@ 2020-06-08 23:06 ` Sasha Levin
  2020-06-08 23:06 ` [PATCH AUTOSEL 5.6 286/606] csky: Fixup raw_copy_from_user() Sasha Levin
  3 siblings, 0 replies; 4+ messages in thread
From: Sasha Levin @ 2020-06-08 23:06 UTC (permalink / raw)
  To: linux-kernel, stable; +Cc: Liu Yibin, Guo Ren, Sasha Levin, linux-csky

From: Liu Yibin <jiulong@linux.alibaba.com>

[ Upstream commit 6633a5aa8eb6bda70eb3a9837efd28a67ccc6e0a ]

Interrupt has been disabled in __schedule() with local_irq_disable()
and enabled in finish_task_switch->finish_lock_switch() with
local_irq_enabled(), So needn't to disable irq here.

Signed-off-by: Liu Yibin <jiulong@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/csky/kernel/entry.S | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S
index 007706328000..9718388448a4 100644
--- a/arch/csky/kernel/entry.S
+++ b/arch/csky/kernel/entry.S
@@ -318,8 +318,6 @@ ENTRY(__switch_to)
 
 	mfcr	a2, psr			/* Save PSR value */
 	stw	a2, (a3, THREAD_SR)	/* Save PSR in task struct */
-	bclri	a2, 6			/* Disable interrupts */
-	mtcr	a2, psr
 
 	SAVE_SWITCH_STACK
 
-- 
2.25.1


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH AUTOSEL 5.6 286/606] csky: Fixup raw_copy_from_user()
       [not found] <20200608231211.3363633-1-sashal@kernel.org>
                   ` (2 preceding siblings ...)
  2020-06-08 23:06 ` [PATCH AUTOSEL 5.6 281/606] csky: Fixup remove duplicate irq_disable Sasha Levin
@ 2020-06-08 23:06 ` Sasha Levin
  3 siblings, 0 replies; 4+ messages in thread
From: Sasha Levin @ 2020-06-08 23:06 UTC (permalink / raw)
  To: linux-kernel, stable; +Cc: Al Viro, Guo Ren, Sasha Levin, linux-csky

From: Al Viro <viro@zeniv.linux.org.uk>

[ Upstream commit 51bb38cb78363fdad1f89e87357b7bc73e39ba88 ]

If raw_copy_from_user(to, from, N) returns K, callers expect
the first N - K bytes starting at to to have been replaced with
the contents of corresponding area starting at from and the last
K bytes of destination *left* *unmodified*.

What arch/sky/lib/usercopy.c is doing is broken - it can lead to e.g.
data corruption on write(2).

raw_copy_to_user() is inaccurate about return value, which is a bug,
but consequences are less drastic than for raw_copy_from_user().
And just what are those access_ok() doing in there?  I mean, look into
linux/uaccess.h; that's where we do that check (as well as zero tail
on failure in the callers that need zeroing).

AFAICS, all of that shouldn't be hard to fix; something like a patch
below might make a useful starting point.

I would suggest moving these macros into usercopy.c (they are never
used anywhere else) and possibly expanding them there; if you leave
them alive, please at least rename __copy_user_zeroing(). Again,
it must not zero anything on failed read.

Said that, I'm not sure we won't be better off simply turning
usercopy.c into usercopy.S - all that is left there is a couple of
functions, each consisting only of inline asm.

Guo Ren reply:

Yes, raw_copy_from_user is wrong, it's no need zeroing code.

unsigned long _copy_from_user(void *to, const void __user *from,
unsigned long n)
{
        unsigned long res = n;
        might_fault();
        if (likely(access_ok(from, n))) {
                kasan_check_write(to, n);
                res = raw_copy_from_user(to, from, n);
        }
        if (unlikely(res))
                memset(to + (n - res), 0, res);
        return res;
}
EXPORT_SYMBOL(_copy_from_user);

You are right and access_ok() should be removed.

but, how about:
do {
...
        "2:     stw     %3, (%1, 0)     \n"             \
+       "       subi    %0, 4          \n"               \
        "9:     stw     %4, (%1, 4)     \n"             \
+       "       subi    %0, 4          \n"               \
        "10:    stw     %5, (%1, 8)     \n"             \
+       "       subi    %0, 4          \n"               \
        "11:    stw     %6, (%1, 12)    \n"             \
+       "       subi    %0, 4          \n"               \
        "       addi    %2, 16          \n"             \
        "       addi    %1, 16          \n"             \

Don't expand __ex_table

AI Viro reply:

Hey, I've no idea about the instruction scheduling on csky -
if that doesn't slow the things down, all the better.  It's just
that copy_to_user() and friends are on fairly hot codepaths,
and in quite a few situations they will dominate the speed of
e.g. read(2).  So I tried to keep the fast path unchanged.
Up to the architecture maintainers, obviously.  Which would be
you...

As for the fixups size increase (__ex_table size is unchanged)...
You have each of those macros expanded exactly once.
So the size is not a serious argument, IMO - useless complexity
would be, if it is, in fact, useless; the size... not really,
especially since those extra subi will at least offset it.

Again, up to you - asm optimizations of (essentially)
memcpy()-style loops are tricky and can depend upon the
fairly subtle details of architecture.  So even on something
I know reasonably well I would resort to direct experiments
if I can't pass the buck to architecture maintainers.

It *is* worth optimizing - this is where read() from a file
that is already in page cache spends most of the time, etc.

Guo Ren reply:

Thx, after fixup some typo “sub %0, 4”, apply the patch.

TODO:
 - user copy/from codes are still need optimizing.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/csky/include/asm/uaccess.h | 49 +++++++++++++++++----------------
 arch/csky/lib/usercopy.c        |  8 ++----
 2 files changed, 28 insertions(+), 29 deletions(-)

diff --git a/arch/csky/include/asm/uaccess.h b/arch/csky/include/asm/uaccess.h
index eaa1c3403a42..60f8a4112588 100644
--- a/arch/csky/include/asm/uaccess.h
+++ b/arch/csky/include/asm/uaccess.h
@@ -254,7 +254,7 @@ do {								\
 
 extern int __get_user_bad(void);
 
-#define __copy_user(to, from, n)			\
+#define ___copy_to_user(to, from, n)			\
 do {							\
 	int w0, w1, w2, w3;				\
 	asm volatile(					\
@@ -289,31 +289,34 @@ do {							\
 	"       subi    %0, 4           \n"		\
 	"       br      3b              \n"		\
 	"5:     cmpnei  %0, 0           \n"  /* 1B */   \
-	"       bf      8f              \n"		\
+	"       bf      13f             \n"		\
 	"       ldb     %3, (%2, 0)     \n"		\
 	"6:     stb     %3, (%1, 0)     \n"		\
 	"       addi    %2,  1          \n"		\
 	"       addi    %1,  1          \n"		\
 	"       subi    %0,  1          \n"		\
 	"       br      5b              \n"		\
-	"7:     br      8f              \n"		\
+	"7:     subi	%0,  4          \n"		\
+	"8:     subi	%0,  4          \n"		\
+	"12:    subi	%0,  4          \n"		\
+	"       br      13f             \n"		\
 	".section __ex_table, \"a\"     \n"		\
 	".align   2                     \n"		\
-	".long    2b, 7b                \n"		\
-	".long    9b, 7b                \n"		\
-	".long   10b, 7b                \n"		\
+	".long    2b, 13f               \n"		\
+	".long    4b, 13f               \n"		\
+	".long    6b, 13f               \n"		\
+	".long    9b, 12b               \n"		\
+	".long   10b, 8b                \n"		\
 	".long   11b, 7b                \n"		\
-	".long    4b, 7b                \n"		\
-	".long    6b, 7b                \n"		\
 	".previous                      \n"		\
-	"8:                             \n"		\
+	"13:                            \n"		\
 	: "=r"(n), "=r"(to), "=r"(from), "=r"(w0),	\
 	  "=r"(w1), "=r"(w2), "=r"(w3)			\
 	: "0"(n), "1"(to), "2"(from)			\
 	: "memory");					\
 } while (0)
 
-#define __copy_user_zeroing(to, from, n)		\
+#define ___copy_from_user(to, from, n)			\
 do {							\
 	int tmp;					\
 	int nsave;					\
@@ -356,22 +359,22 @@ do {							\
 	"       addi    %1,  1          \n"		\
 	"       subi    %0,  1          \n"		\
 	"       br      5b              \n"		\
-	"8:     mov     %3, %0          \n"		\
-	"       movi    %4, 0           \n"		\
-	"9:     stb     %4, (%1, 0)     \n"		\
-	"       addi    %1, 1           \n"		\
-	"       subi    %3, 1           \n"		\
-	"       cmpnei  %3, 0           \n"		\
-	"       bt      9b              \n"		\
-	"       br      7f              \n"		\
+	"8:     stw     %3, (%1, 0)     \n"		\
+	"       subi    %0, 4           \n"		\
+	"       bf      7f              \n"		\
+	"9:     subi    %0, 8           \n"		\
+	"       bf      7f              \n"		\
+	"13:    stw     %3, (%1, 8)     \n"		\
+	"       subi    %0, 12          \n"		\
+	"       bf      7f              \n"		\
 	".section __ex_table, \"a\"     \n"		\
 	".align   2                     \n"		\
-	".long    2b, 8b                \n"		\
+	".long    2b, 7f                \n"		\
+	".long    4b, 7f                \n"		\
+	".long    6b, 7f                \n"		\
 	".long   10b, 8b                \n"		\
-	".long   11b, 8b                \n"		\
-	".long   12b, 8b                \n"		\
-	".long    4b, 8b                \n"		\
-	".long    6b, 8b                \n"		\
+	".long   11b, 9b                \n"		\
+	".long   12b,13b                \n"		\
 	".previous                      \n"		\
 	"7:                             \n"		\
 	: "=r"(n), "=r"(to), "=r"(from), "=r"(nsave),	\
diff --git a/arch/csky/lib/usercopy.c b/arch/csky/lib/usercopy.c
index 647a23986fb5..3c9bd645e643 100644
--- a/arch/csky/lib/usercopy.c
+++ b/arch/csky/lib/usercopy.c
@@ -7,10 +7,7 @@
 unsigned long raw_copy_from_user(void *to, const void *from,
 			unsigned long n)
 {
-	if (access_ok(from, n))
-		__copy_user_zeroing(to, from, n);
-	else
-		memset(to, 0, n);
+	___copy_from_user(to, from, n);
 	return n;
 }
 EXPORT_SYMBOL(raw_copy_from_user);
@@ -18,8 +15,7 @@ EXPORT_SYMBOL(raw_copy_from_user);
 unsigned long raw_copy_to_user(void *to, const void *from,
 			unsigned long n)
 {
-	if (access_ok(to, n))
-		__copy_user(to, from, n);
+	___copy_to_user(to, from, n);
 	return n;
 }
 EXPORT_SYMBOL(raw_copy_to_user);
-- 
2.25.1


^ permalink raw reply	[flat|nested] 4+ messages in thread

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Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <20200608231211.3363633-1-sashal@kernel.org>
2020-06-08 23:06 ` [PATCH AUTOSEL 5.6 279/606] csky: Fixup msa highest 3 bits mask Sasha Levin
2020-06-08 23:06 ` [PATCH AUTOSEL 5.6 280/606] csky: Fixup perf callchain unwind Sasha Levin
2020-06-08 23:06 ` [PATCH AUTOSEL 5.6 281/606] csky: Fixup remove duplicate irq_disable Sasha Levin
2020-06-08 23:06 ` [PATCH AUTOSEL 5.6 286/606] csky: Fixup raw_copy_from_user() Sasha Levin

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