From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Al Viro <viro@zeniv.linux.org.uk>,
James Hogan <james.hogan@imgtec.com>,
linux-metag@vger.kernel.org
Subject: [PATCH 4.4 18/32] metag/usercopy: Zero rest of buffer from copy_from_user
Date: Mon, 10 Apr 2017 18:39:08 +0200 [thread overview]
Message-ID: <20170410163841.726453375@linuxfoundation.org> (raw)
In-Reply-To: <20170410163839.055472822@linuxfoundation.org>
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: James Hogan <james.hogan@imgtec.com>
commit 563ddc1076109f2b3f88e6d355eab7b6fd4662cb upstream.
Currently we try to zero the destination for a failed read from userland
in fixup code in the usercopy.c macros. The rest of the destination
buffer is then zeroed from __copy_user_zeroing(), which is used for both
copy_from_user() and __copy_from_user().
Unfortunately we fail to zero in the fixup code as D1Ar1 is set to 0
before the fixup code entry labels, and __copy_from_user() shouldn't even
be zeroing the rest of the buffer.
Move the zeroing out into copy_from_user() and rename
__copy_user_zeroing() to raw_copy_from_user() since it no longer does
any zeroing. This also conveniently matches the name needed for
RAW_COPY_USER support in a later patch.
Fixes: 373cd784d0fc ("metag: Memory handling")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-metag@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/metag/include/asm/uaccess.h | 15 +++++-----
arch/metag/lib/usercopy.c | 57 ++++++++++++---------------------------
2 files changed, 26 insertions(+), 46 deletions(-)
--- a/arch/metag/include/asm/uaccess.h
+++ b/arch/metag/include/asm/uaccess.h
@@ -197,20 +197,21 @@ extern long __must_check strnlen_user(co
#define strlen_user(str) strnlen_user(str, 32767)
-extern unsigned long __must_check __copy_user_zeroing(void *to,
- const void __user *from,
- unsigned long n);
+extern unsigned long raw_copy_from_user(void *to, const void __user *from,
+ unsigned long n);
static inline unsigned long
copy_from_user(void *to, const void __user *from, unsigned long n)
{
+ unsigned long res = n;
if (likely(access_ok(VERIFY_READ, from, n)))
- return __copy_user_zeroing(to, from, n);
- memset(to, 0, n);
- return n;
+ res = raw_copy_from_user(to, from, n);
+ if (unlikely(res))
+ memset(to + (n - res), 0, res);
+ return res;
}
-#define __copy_from_user(to, from, n) __copy_user_zeroing(to, from, n)
+#define __copy_from_user(to, from, n) raw_copy_from_user(to, from, n)
#define __copy_from_user_inatomic __copy_from_user
extern unsigned long __must_check __copy_user(void __user *to,
--- a/arch/metag/lib/usercopy.c
+++ b/arch/metag/lib/usercopy.c
@@ -29,7 +29,6 @@
COPY \
"1:\n" \
" .section .fixup,\"ax\"\n" \
- " MOV D1Ar1,#0\n" \
FIXUP \
" MOVT D1Ar1,#HI(1b)\n" \
" JUMP D1Ar1,#LO(1b)\n" \
@@ -637,16 +636,14 @@ EXPORT_SYMBOL(__copy_user);
__asm_copy_user_cont(to, from, ret, \
" GETB D1Ar1,[%1++]\n" \
"2: SETB [%0++],D1Ar1\n", \
- "3: ADD %2,%2,#1\n" \
- " SETB [%0++],D1Ar1\n", \
+ "3: ADD %2,%2,#1\n", \
" .long 2b,3b\n")
#define __asm_copy_from_user_2x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
__asm_copy_user_cont(to, from, ret, \
" GETW D1Ar1,[%1++]\n" \
"2: SETW [%0++],D1Ar1\n" COPY, \
- "3: ADD %2,%2,#2\n" \
- " SETW [%0++],D1Ar1\n" FIXUP, \
+ "3: ADD %2,%2,#2\n" FIXUP, \
" .long 2b,3b\n" TENTRY)
#define __asm_copy_from_user_2(to, from, ret) \
@@ -656,32 +653,26 @@ EXPORT_SYMBOL(__copy_user);
__asm_copy_from_user_2x_cont(to, from, ret, \
" GETB D1Ar1,[%1++]\n" \
"4: SETB [%0++],D1Ar1\n", \
- "5: ADD %2,%2,#1\n" \
- " SETB [%0++],D1Ar1\n", \
+ "5: ADD %2,%2,#1\n", \
" .long 4b,5b\n")
#define __asm_copy_from_user_4x_cont(to, from, ret, COPY, FIXUP, TENTRY) \
__asm_copy_user_cont(to, from, ret, \
" GETD D1Ar1,[%1++]\n" \
"2: SETD [%0++],D1Ar1\n" COPY, \
- "3: ADD %2,%2,#4\n" \
- " SETD [%0++],D1Ar1\n" FIXUP, \
+ "3: ADD %2,%2,#4\n" FIXUP, \
" .long 2b,3b\n" TENTRY)
#define __asm_copy_from_user_4(to, from, ret) \
__asm_copy_from_user_4x_cont(to, from, ret, "", "", "")
-
#define __asm_copy_from_user_8x64(to, from, ret) \
asm volatile ( \
" GETL D0Ar2,D1Ar1,[%1++]\n" \
"2: SETL [%0++],D0Ar2,D1Ar1\n" \
"1:\n" \
" .section .fixup,\"ax\"\n" \
- " MOV D1Ar1,#0\n" \
- " MOV D0Ar2,#0\n" \
"3: ADD %2,%2,#8\n" \
- " SETL [%0++],D0Ar2,D1Ar1\n" \
" MOVT D0Ar2,#HI(1b)\n" \
" JUMP D0Ar2,#LO(1b)\n" \
" .previous\n" \
@@ -721,11 +712,12 @@ EXPORT_SYMBOL(__copy_user);
"SUB %1, %1, #4\n")
-/* Copy from user to kernel, zeroing the bytes that were inaccessible in
- userland. The return-value is the number of bytes that were
- inaccessible. */
-unsigned long __copy_user_zeroing(void *pdst, const void __user *psrc,
- unsigned long n)
+/*
+ * Copy from user to kernel. The return-value is the number of bytes that were
+ * inaccessible.
+ */
+unsigned long raw_copy_from_user(void *pdst, const void __user *psrc,
+ unsigned long n)
{
register char *dst asm ("A0.2") = pdst;
register const char __user *src asm ("A1.2") = psrc;
@@ -738,7 +730,7 @@ unsigned long __copy_user_zeroing(void *
__asm_copy_from_user_1(dst, src, retn);
n--;
if (retn)
- goto copy_exception_bytes;
+ return retn + n;
}
if ((unsigned long) dst & 1) {
/* Worst case - byte copy */
@@ -746,14 +738,14 @@ unsigned long __copy_user_zeroing(void *
__asm_copy_from_user_1(dst, src, retn);
n--;
if (retn)
- goto copy_exception_bytes;
+ return retn + n;
}
}
if (((unsigned long) src & 2) && n >= 2) {
__asm_copy_from_user_2(dst, src, retn);
n -= 2;
if (retn)
- goto copy_exception_bytes;
+ return retn + n;
}
if ((unsigned long) dst & 2) {
/* Second worst case - word copy */
@@ -761,7 +753,7 @@ unsigned long __copy_user_zeroing(void *
__asm_copy_from_user_2(dst, src, retn);
n -= 2;
if (retn)
- goto copy_exception_bytes;
+ return retn + n;
}
}
@@ -777,7 +769,7 @@ unsigned long __copy_user_zeroing(void *
__asm_copy_from_user_8x64(dst, src, retn);
n -= 8;
if (retn)
- goto copy_exception_bytes;
+ return retn + n;
}
}
@@ -793,7 +785,7 @@ unsigned long __copy_user_zeroing(void *
__asm_copy_from_user_8x64(dst, src, retn);
n -= 8;
if (retn)
- goto copy_exception_bytes;
+ return retn + n;
}
}
#endif
@@ -803,7 +795,7 @@ unsigned long __copy_user_zeroing(void *
n -= 4;
if (retn)
- goto copy_exception_bytes;
+ return retn + n;
}
/* If we get here, there were no memory read faults. */
@@ -829,21 +821,8 @@ unsigned long __copy_user_zeroing(void *
/* If we get here, retn correctly reflects the number of failing
bytes. */
return retn;
-
- copy_exception_bytes:
- /* We already have "retn" bytes cleared, and need to clear the
- remaining "n" bytes. A non-optimized simple byte-for-byte in-line
- memset is preferred here, since this isn't speed-critical code and
- we'd rather have this a leaf-function than calling memset. */
- {
- char *endp;
- for (endp = dst + n; dst < endp; dst++)
- *dst = 0;
- }
-
- return retn + n;
}
-EXPORT_SYMBOL(__copy_user_zeroing);
+EXPORT_SYMBOL(raw_copy_from_user);
#define __asm_clear_8x64(to, ret) \
asm volatile ( \
next prev parent reply other threads:[~2017-04-10 16:40 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-10 16:38 [PATCH 4.4 00/32] 4.4.61-stable review Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 01/32] drm/vmwgfx: Type-check lookups of fence objects Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 02/32] drm/vmwgfx: NULL pointer dereference in vmw_surface_define_ioctl() Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 03/32] drm/vmwgfx: avoid calling vzalloc with a 0 size in vmw_get_cap_3d_ioctl() Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 04/32] drm/ttm, drm/vmwgfx: Relax permission checking when opening surfaces Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 05/32] drm/vmwgfx: Remove getparam error message Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 06/32] drm/vmwgfx: fix integer overflow in vmw_surface_define_ioctl() Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 07/32] sysfs: be careful of error returns from ops->show() Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 08/32] staging: android: ashmem: lseek failed due to no FMODE_LSEEK Greg Kroah-Hartman
2017-04-10 16:38 ` [PATCH 4.4 09/32] arm/arm64: KVM: Take mmap_sem in stage2_unmap_vm Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 10/32] arm/arm64: KVM: Take mmap_sem in kvm_arch_prepare_memory_region Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 11/32] iio: bmg160: reset chip when probing Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 12/32] Reset TreeId to zero on SMB2 TREE_CONNECT Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 13/32] ptrace: fix PTRACE_LISTEN race corrupting task->state Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 14/32] ring-buffer: Fix return value check in test_ringbuffer() Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 15/32] metag/usercopy: Drop unused macros Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 16/32] metag/usercopy: Fix alignment error checking Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 17/32] metag/usercopy: Add early abort to copy_to_user Greg Kroah-Hartman
2017-04-10 16:39 ` Greg Kroah-Hartman [this message]
2017-04-10 16:39 ` [PATCH 4.4 19/32] metag/usercopy: Set flags before ADDZ Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 20/32] metag/usercopy: Fix src fixup in from user rapf loops Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 21/32] metag/usercopy: Add missing fixups Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 22/32] powerpc/mm: Add missing global TLB invalidate if cxl is active Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 23/32] powerpc: Dont try to fix up misaligned load-with-reservation instructions Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 24/32] nios2: reserve boot memory for device tree Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 25/32] s390/decompressor: fix initrd corruption caused by bss clear Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 26/32] s390/uaccess: get_user() should zero on failure (again) Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 27/32] MIPS: Force o32 fp64 support on 32bit MIPS64r6 kernels Greg Kroah-Hartman
2017-04-14 23:45 ` Maciej W. Rozycki
2017-04-19 13:13 ` Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 28/32] MIPS: ralink: Fix typos in rt3883 pinctrl Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 29/32] MIPS: End spinlocks with .insn Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 30/32] MIPS: Lantiq: fix missing xbar kernel panic Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 31/32] MIPS: Flush wrong invalid FTLB entry for huge page Greg Kroah-Hartman
2017-04-10 16:39 ` [PATCH 4.4 32/32] mm/mempolicy.c: fix error handling in set_mempolicy and mbind Greg Kroah-Hartman
2017-04-10 20:38 ` [PATCH 4.4 00/32] 4.4.61-stable review Shuah Khan
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