From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org
Subject: [PATCH v2 09/20] arm: propagate the calling convention changes down to csum_partial_copy_from_user()
Date: Fri, 24 Jul 2020 02:25:35 +0100 [thread overview]
Message-ID: <20200724012546.302155-9-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20200724012546.302155-1-viro@ZenIV.linux.org.uk>
From: Al Viro <viro@zeniv.linux.org.uk>
... and get rid of the "clean the destination on error" crap.
Simplifies the fault handlers and the function itself...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
arch/arm/include/asm/checksum.h | 7 ++-----
arch/arm/lib/csumpartialcopy.S | 1 -
arch/arm/lib/csumpartialcopygeneric.S | 1 +
arch/arm/lib/csumpartialcopyuser.S | 26 ++++++--------------------
4 files changed, 9 insertions(+), 26 deletions(-)
diff --git a/arch/arm/include/asm/checksum.h b/arch/arm/include/asm/checksum.h
index 1601c132b064..f0f54aef3724 100644
--- a/arch/arm/include/asm/checksum.h
+++ b/arch/arm/include/asm/checksum.h
@@ -38,20 +38,17 @@ __wsum
csum_partial_copy_nocheck(const void *src, void *dst, int len);
__wsum
-csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *err_ptr);
+csum_partial_copy_from_user(const void __user *src, void *dst, int len);
#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
#define _HAVE_ARCH_CSUM_AND_COPY
static inline
__wsum csum_and_copy_from_user(const void __user *src, void *dst, int len)
{
- int err = 0;
-
if (!access_ok(src, len))
return 0;
- sum = csum_partial_copy_from_user(src, dst, len, ~0U, &err);
- return err ? 0 : sum;
+ return csum_partial_copy_from_user(src, dst, len);
}
/*
diff --git a/arch/arm/lib/csumpartialcopy.S b/arch/arm/lib/csumpartialcopy.S
index aab914fbc86b..1ca6aadd649c 100644
--- a/arch/arm/lib/csumpartialcopy.S
+++ b/arch/arm/lib/csumpartialcopy.S
@@ -16,7 +16,6 @@
.macro save_regs
stmfd sp!, {r1, r4 - r8, lr}
- mov r3, #0
.endm
.macro load_regs
diff --git a/arch/arm/lib/csumpartialcopygeneric.S b/arch/arm/lib/csumpartialcopygeneric.S
index 0b706a39a677..0fd5c10e90a7 100644
--- a/arch/arm/lib/csumpartialcopygeneric.S
+++ b/arch/arm/lib/csumpartialcopygeneric.S
@@ -86,6 +86,7 @@ sum .req r3
FN_ENTRY
save_regs
+ mov sum, #-1
cmp len, #8 @ Ensure that we have at least
blo .Lless8 @ 8 bytes to copy.
diff --git a/arch/arm/lib/csumpartialcopyuser.S b/arch/arm/lib/csumpartialcopyuser.S
index 6bd3a93eaa3c..6928781e6bee 100644
--- a/arch/arm/lib/csumpartialcopyuser.S
+++ b/arch/arm/lib/csumpartialcopyuser.S
@@ -62,9 +62,9 @@
/*
* unsigned int
- * csum_partial_copy_from_user(const char *src, char *dst, int len, int sum, int *err_ptr)
- * r0 = src, r1 = dst, r2 = len, r3 = sum, [sp] = *err_ptr
- * Returns : r0 = checksum, [[sp, #0], #0] = 0 or -EFAULT
+ * csum_partial_copy_from_user(const char *src, char *dst, int len)
+ * r0 = src, r1 = dst, r2 = len
+ * Returns : r0 = checksum or 0
*/
#define FN_ENTRY ENTRY(csum_partial_copy_from_user)
@@ -73,25 +73,11 @@
#include "csumpartialcopygeneric.S"
/*
- * FIXME: minor buglet here
- * We don't return the checksum for the data present in the buffer. To do
- * so properly, we would have to add in whatever registers were loaded before
- * the fault, which, with the current asm above is not predictable.
+ * We report fault by returning 0 csum - impossible in normal case, since
+ * we start with 0xffffffff for initial sum.
*/
.pushsection .text.fixup,"ax"
.align 4
-9001: mov r4, #-EFAULT
-#ifdef CONFIG_CPU_SW_DOMAIN_PAN
- ldr r5, [sp, #9*4] @ *err_ptr
-#else
- ldr r5, [sp, #8*4] @ *err_ptr
-#endif
- str r4, [r5]
- ldmia sp, {r1, r2} @ retrieve dst, len
- add r2, r2, r1
- mov r0, #0 @ zero the buffer
-9002: teq r2, r1
- strbne r0, [r1], #1
- bne 9002b
+9001: mov r0, #0
load_regs
.popsection
--
2.11.0
next prev parent reply other threads:[~2020-07-24 1:26 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-21 20:24 [RFC][CFT][PATCHSET] saner calling conventions for csum-and-copy primitives Al Viro
2020-07-21 20:25 ` [PATCH 01/18] skb_copy_and_csum_bits(): don't bother with the last argument Al Viro
2020-07-21 20:25 ` [PATCH 02/18] icmp_push_reply(): reorder adding the checksum up Al Viro
2020-07-21 20:25 ` [PATCH 03/18] csum_partial_copy_nocheck(): drop the last argument Al Viro
2020-07-21 20:25 ` [PATCH 04/18] csum_and_copy_..._user(): pass 0xffffffff instead of 0 as initial sum Al Viro
2020-07-21 20:55 ` Linus Torvalds
2020-07-21 20:58 ` Linus Torvalds
2020-07-21 21:11 ` Al Viro
2020-07-21 21:16 ` Linus Torvalds
2020-07-25 17:54 ` Al Viro
2020-07-22 9:45 ` David Laight
2020-07-22 9:27 ` David Laight
2020-07-22 14:42 ` Al Viro
2020-07-22 15:22 ` David Laight
2020-07-22 15:54 ` Al Viro
2020-07-22 16:17 ` David Laight
2020-07-22 17:39 ` Al Viro
2020-07-23 8:29 ` David Laight
2020-07-23 13:54 ` David Laight
2020-07-23 14:30 ` David Laight
2020-07-23 14:53 ` Al Viro
2020-07-23 15:19 ` David Laight
2020-07-23 15:21 ` Al Viro
2020-07-23 15:36 ` David Laight
2020-07-21 20:25 ` [PATCH 05/18] saner calling conventions for csum_and_copy_..._user() Al Viro
2020-07-21 20:25 ` [PATCH 06/18] alpha: propagate the calling convention changes down to csum_partial_copy.c helpers Al Viro
2020-07-21 20:25 ` [PATCH 07/18] arm: propagate the calling convention changes down to csum_partial_copy_from_user() Al Viro
2020-07-21 20:25 ` [PATCH 08/18] m68k: get rid of zeroing destination on error in csum_and_copy_from_user() Al Viro
2020-07-21 20:25 ` [PATCH 09/18] sh: propage the calling conventions change down to csum_partial_copy_generic() Al Viro
2020-07-21 20:25 ` [PATCH 10/18] i386: propagate " Al Viro
2020-07-21 20:25 ` [PATCH 11/18] sparc32: propagate the calling conventions change down to __csum_partial_copy_sparc_generic() Al Viro
2020-07-22 1:20 ` David Miller
2020-07-21 20:25 ` [PATCH 12/18] mips: csum_and_copy_{to,from}_user() are never called under KERNEL_DS Al Viro
2020-07-21 20:25 ` [PATCH 13/18] mips: __csum_partial_copy_kernel() has no users left Al Viro
2020-07-21 20:25 ` [PATCH 14/18] mips: propagate the calling convention change down into __csum_partial_copy_..._user() Al Viro
2020-07-21 20:25 ` [PATCH 15/18] xtensa: propagate the calling conventions change down into csum_partial_copy_generic() Al Viro
2020-07-22 8:56 ` Max Filippov
2020-07-21 20:25 ` [PATCH 16/18] sparc64: propagate the calling convention changes down to __csum_partial_copy_...() Al Viro
2020-07-22 1:21 ` David Miller
2020-07-21 20:25 ` [PATCH 17/18] amd64: switch csum_partial_copy_generic() to new calling conventions Al Viro
2020-07-21 20:25 ` [PATCH 18/18] ppc: propagate the calling conventions change down to csum_partial_copy_generic() Al Viro
2020-07-24 1:25 ` [RFC][CFT][PATCHSET v2] saner calling conventions for csum-and-copy primitives Al Viro
2020-07-24 1:25 ` [PATCH v2 01/20] xtensa: fix access check in csum_and_copy_from_user Al Viro
2020-07-24 1:25 ` [PATCH v2 02/20] skb_copy_and_csum_bits(): don't bother with the last argument Al Viro
2020-07-24 1:25 ` [PATCH v2 03/20] icmp_push_reply(): reorder adding the checksum up Al Viro
2020-07-24 1:25 ` [PATCH v2 04/20] unify generic instances of csum_partial_copy_nocheck() Al Viro
2020-07-24 6:41 ` Christoph Hellwig
2020-07-24 12:19 ` Al Viro
2020-07-24 12:23 ` Christoph Hellwig
2020-07-24 12:30 ` Al Viro
2020-07-26 7:11 ` Christoph Hellwig
2020-07-27 3:58 ` Al Viro
2020-07-24 1:25 ` [PATCH v2 05/20] csum_partial_copy_nocheck(): drop the last argument Al Viro
2020-07-24 12:21 ` kernel test robot
2020-07-24 1:25 ` [PATCH v2 06/20] csum_and_copy_..._user(): pass 0xffffffff instead of 0 as initial sum Al Viro
2020-07-24 1:25 ` [PATCH v2 07/20] saner calling conventions for csum_and_copy_..._user() Al Viro
2020-07-24 1:25 ` [PATCH v2 08/20] alpha: propagate the calling convention changes down to csum_partial_copy.c helpers Al Viro
2020-07-24 1:25 ` Al Viro [this message]
2020-07-24 1:25 ` [PATCH v2 10/20] m68k: get rid of zeroing destination on error in csum_and_copy_from_user() Al Viro
2020-07-24 1:25 ` [PATCH v2 11/20] sh: propage the calling conventions change down to csum_partial_copy_generic() Al Viro
2020-07-24 1:25 ` [PATCH v2 12/20] i386: propagate " Al Viro
2020-07-24 1:25 ` [PATCH v2 13/20] sparc32: propagate the calling conventions change down to __csum_partial_copy_sparc_generic() Al Viro
2020-07-24 1:25 ` [PATCH v2 14/20] mips: csum_and_copy_{to,from}_user() are never called under KERNEL_DS Al Viro
2020-07-24 1:25 ` [PATCH v2 15/20] mips: __csum_partial_copy_kernel() has no users left Al Viro
2020-07-24 1:25 ` [PATCH v2 16/20] mips: propagate the calling convention change down into __csum_partial_copy_..._user() Al Viro
2020-07-24 1:25 ` [PATCH v2 17/20] xtensa: propagate the calling conventions change down into csum_partial_copy_generic() Al Viro
2020-07-24 1:25 ` [PATCH v2 18/20] sparc64: propagate the calling convention changes down to __csum_partial_copy_...() Al Viro
2020-07-24 1:25 ` [PATCH v2 19/20] amd64: switch csum_partial_copy_generic() to new calling conventions Al Viro
2020-07-24 1:25 ` [PATCH v2 20/20] ppc: propagate the calling conventions change down to csum_partial_copy_generic() Al Viro
2020-10-14 22:26 ` Jason A. Donenfeld
2020-10-14 22:51 ` Linus Torvalds
2020-10-14 22:53 ` Linus Torvalds
2020-10-14 22:54 ` Jason A. Donenfeld
2020-10-14 22:53 ` Jason A. Donenfeld
2020-10-14 23:12 ` Al Viro
2020-10-14 23:02 ` [PATCH] powerpc32: don't adjust unmoved stack pointer in csum_partial_copy_generic() epilogue Jason A. Donenfeld
2020-10-14 23:05 ` Linus Torvalds
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