Re: [RFC PATCH 0/3] arc: remove CONFIG_SET_FS
On 2/1/22 06:55, Sergey Matyukevich wrote:
Hi all,
This patch series removes SET_FS support for arc.
Sergey Matyukevich (3):
arc: use BUILD_BUG for invalid sizes in get_user/put_user
arc: provide __{get,put}_kernel_nofault
arc: remove set_fs()
arch/arc/Kconfig | 1 -
arch/arc/include/asm/segment.h | 20 -
arch/arc/include/asm/thread_info.h | 3 --
arch/arc/include/asm/uaccess.h | 48 --
4 files changed, 32 insertions(+), 40 deletions(-)
delete mode 100644 arch/arc/include/asm/segment.h
Nit - in future please use uppercase "ARC" for prefixing patches.
Added to for-next.
Thx,
-Vineet
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Re: [RFC PATCH 1/3] arc: use BUILD_BUG for invalid sizes in get_user/put_user
On Tue, Feb 01, 2022 at 05:55:36PM +0300, Sergey Matyukevich wrote: > From: Sergey Matyukevich > > Use BUILD_BUG for compile-time check of invalid sizes passed > to get_user/put_user functions. Looks good: Reviewed-by: Christoph Hellwig ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [RFC PATCH 3/3] arc: remove set_fs()
Looks good: Reviewed-by: Christoph Hellwig ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [RFC PATCH 2/3] arc: provide __{get,put}_kernel_nofault
On Tue, Feb 01, 2022 at 05:55:37PM +0300, Sergey Matyukevich wrote:
> From: Sergey Matyukevich
>
> Implement the non-faulting kernel access helpers directly
> instead of using uaccess routines under set_fs(KERNEL_DS).
>
> Signed-off-by: Sergey Matyukevich
> ---
> arch/arc/include/asm/uaccess.h | 22 ++
> 1 file changed, 22 insertions(+)
>
> diff --git a/arch/arc/include/asm/uaccess.h b/arch/arc/include/asm/uaccess.h
> index 9d1205bf90f1..c14b692a0a4e 100644
> --- a/arch/arc/include/asm/uaccess.h
> +++ b/arch/arc/include/asm/uaccess.h
> @@ -657,6 +657,28 @@ static inline unsigned long __arc_clear_user(void __user
> *to, unsigned long n)
> return res;
> }
>
> +#define HAVE_GET_KERNEL_NOFAULT
> +
> +#define __get_kernel_nofault(dst, src, type, err_label)
> \
> + do {\
Normal kernel style doesn't indent the do { } while inside of
function-like macros.
Otherwise this looks good.
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[RFC PATCH 0/3] arc: remove CONFIG_SET_FS
Hi all,
This patch series removes SET_FS support for arc.
Sergey Matyukevich (3):
arc: use BUILD_BUG for invalid sizes in get_user/put_user
arc: provide __{get,put}_kernel_nofault
arc: remove set_fs()
arch/arc/Kconfig | 1 -
arch/arc/include/asm/segment.h | 20 -
arch/arc/include/asm/thread_info.h | 3 --
arch/arc/include/asm/uaccess.h | 48 --
4 files changed, 32 insertions(+), 40 deletions(-)
delete mode 100644 arch/arc/include/asm/segment.h
--
2.35.0
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[RFC PATCH 1/3] arc: use BUILD_BUG for invalid sizes in get_user/put_user
From: Sergey Matyukevich Use BUILD_BUG for compile-time check of invalid sizes passed to get_user/put_user functions. Signed-off-by: Sergey Matyukevich --- arch/arc/include/asm/uaccess.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arc/include/asm/uaccess.h b/arch/arc/include/asm/uaccess.h index 783bfdb3bfa3..9d1205bf90f1 100644 --- a/arch/arc/include/asm/uaccess.h +++ b/arch/arc/include/asm/uaccess.h @@ -62,6 +62,7 @@ case 2: __arc_get_user_one(*(k), u, "ldw", __ret); break; \ case 4: __arc_get_user_one(*(k), u, "ld", __ret); break; \ case 8: __arc_get_user_one_64(*(k), u, __ret); break; \ + default: BUILD_BUG(); \ } \ __ret; \ }) @@ -123,6 +124,7 @@ case 2: __arc_put_user_one(*(k), u, "stw", __ret); break; \ case 4: __arc_put_user_one(*(k), u, "st", __ret); break; \ case 8: __arc_put_user_one_64(*(k), u, __ret); break; \ + default: BUILD_BUG(); \ } \ __ret; \ }) -- 2.35.0 ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
[RFC PATCH 2/3] arc: provide __{get,put}_kernel_nofault
From: Sergey Matyukevich
Implement the non-faulting kernel access helpers directly
instead of using uaccess routines under set_fs(KERNEL_DS).
Signed-off-by: Sergey Matyukevich
---
arch/arc/include/asm/uaccess.h | 22 ++
1 file changed, 22 insertions(+)
diff --git a/arch/arc/include/asm/uaccess.h b/arch/arc/include/asm/uaccess.h
index 9d1205bf90f1..c14b692a0a4e 100644
--- a/arch/arc/include/asm/uaccess.h
+++ b/arch/arc/include/asm/uaccess.h
@@ -657,6 +657,28 @@ static inline unsigned long __arc_clear_user(void __user
*to, unsigned long n)
return res;
}
+#define HAVE_GET_KERNEL_NOFAULT
+
+#define __get_kernel_nofault(dst, src, type, err_label)
\
+ do {\
+ long __err; \
+ \
+ __err = __get_user_fn(sizeof(type), (type *)(src), \
+ (type *)(dst)); \
+ if (unlikely(__err))\
+ goto err_label; \
+ } while (0)
+
+#define __put_kernel_nofault(dst, src, type, err_label)
\
+ do {\
+ long __err; \
+ \
+ __err = __put_user_fn(sizeof(type), (type *)(dst), \
+ (type *)(src)); \
+ if (unlikely(__err))\
+ goto err_label; \
+ } while (0)
+
#ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE
#define INLINE_COPY_TO_USER
--
2.35.0
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[RFC PATCH 3/3] arc: remove set_fs()
From: Sergey Matyukevich
Kernel __{get,put}_kernel_nofault operations are implemented for ARC.
There are no other remaining arch/arc specific callers of set_fs().
So just remove it and all the supporting code.
Signed-off-by: Sergey Matyukevich
---
arch/arc/Kconfig | 1 -
arch/arc/include/asm/segment.h | 20
arch/arc/include/asm/thread_info.h | 3 ---
arch/arc/include/asm/uaccess.h | 24
4 files changed, 8 insertions(+), 40 deletions(-)
delete mode 100644 arch/arc/include/asm/segment.h
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 3c2a4753d09b..e0a60a27e14d 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -45,7 +45,6 @@ config ARC
select PCI_SYSCALL if PCI
select PERF_USE_VMALLOC if ARC_CACHE_VIPT_ALIASING
select HAVE_ARCH_JUMP_LABEL if ISA_ARCV2 && !CPU_ENDIAN_BE32
- select SET_FS
select TRACE_IRQFLAGS_SUPPORT
config LOCKDEP_SUPPORT
diff --git a/arch/arc/include/asm/segment.h b/arch/arc/include/asm/segment.h
deleted file mode 100644
index 871f8ab11bfd..
--- a/arch/arc/include/asm/segment.h
+++ /dev/null
@@ -1,20 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
- */
-
-#ifndef __ASMARC_SEGMENT_H
-#define __ASMARC_SEGMENT_H
-
-#ifndef __ASSEMBLY__
-
-typedef unsigned long mm_segment_t;
-
-#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
-
-#define KERNEL_DS MAKE_MM_SEG(0)
-#define USER_DSMAKE_MM_SEG(TASK_SIZE)
-#define uaccess_kernel() (get_fs() == KERNEL_DS)
-
-#endif /* __ASSEMBLY__ */
-#endif /* __ASMARC_SEGMENT_H */
diff --git a/arch/arc/include/asm/thread_info.h
b/arch/arc/include/asm/thread_info.h
index d36863e34bfc..1e0b2e3914d5 100644
--- a/arch/arc/include/asm/thread_info.h
+++ b/arch/arc/include/asm/thread_info.h
@@ -27,7 +27,6 @@
#ifndef __ASSEMBLY__
#include
-#include
/*
* low level task data that entry.S needs immediate access to
@@ -40,7 +39,6 @@ struct thread_info {
unsigned long flags;/* low level flags */
int preempt_count; /* 0 => preemptable, <0 => BUG */
struct task_struct *task; /* main task structure */
- mm_segment_t addr_limit;/* thread address space */
__u32 cpu; /* current CPU */
unsigned long thr_ptr; /* TLS ptr */
};
@@ -56,7 +54,6 @@ struct thread_info {
.flags = 0,\
.cpu= 0,\
.preempt_count = INIT_PREEMPT_COUNT, \
- .addr_limit = KERNEL_DS,\
}
static inline __attribute_const__ struct thread_info *current_thread_info(void)
diff --git a/arch/arc/include/asm/uaccess.h b/arch/arc/include/asm/uaccess.h
index c14b692a0a4e..f07eaf17afaf 100644
--- a/arch/arc/include/asm/uaccess.h
+++ b/arch/arc/include/asm/uaccess.h
@@ -23,14 +23,9 @@
#include /* for generic string functions */
-
-#define __kernel_ok(uaccess_kernel())
-
/*
- * Algorithmically, for __user_ok() we want do:
+ * Algorithmically, for __access_ok() we want do:
* (start < TASK_SIZE) && (start+len < TASK_SIZE)
- * where TASK_SIZE could either be retrieved from thread_info->addr_limit or
- * emitted directly in code.
*
* This can however be rewritten as follows:
* (len <= TASK_SIZE) && (start+len < TASK_SIZE)
@@ -41,16 +36,14 @@
* The reason for rewriting being, for majority of cases, @len is generally
* compile time constant, causing first sub-expression to be compile time
* subsumed.
- *
- * The second part would generate weird large LIMMs e.g. (0x6000_ - 0x10),
- * so we check for TASK_SIZE using get_fs() since the addr_limit load from mem
- * would already have been done at this call site for __kernel_ok()
- *
*/
-#define __user_ok(addr, sz)(((sz) <= TASK_SIZE) && \
-((addr) <= (get_fs() - (sz
-#define __access_ok(addr, sz) (unlikely(__kernel_ok) || \
-likely(__user_ok((addr), (sz
+static inline int __access_ok(unsigned long addr, unsigned long size)
+{
+ __chk_user_ptr(addr);
+ return size <= TASK_SIZE && addr <= TASK_SIZE - size;
+}
+
+#define __access_ok__access_ok
/*** Single byte/hword/word copies **/
@@ -691,7 +684,6 @@ extern unsigned long arc_clear_user_noinline(void __user
*to,
#define __clear_user(d, n) arc_clear_user_noinline(d, n)
#endif
-#include
#include
#endif
--
2.35.0
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