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34cfb106d1
Currently the sram-exec functionality, which allows allocation of
executable memory and provides an API to move code to it, is only
selected in configs for the ARM architecture. Based on commit
5756e9dd0de6 ("ARM: 6640/1: Thumb-2: Symbol manipulation macros for
function body copying") simply copying a C function pointer address
using memcpy without consideration of alignment and Thumb is unsafe on
ARM platforms.
The aforementioned patch introduces the fncpy macro which is a safe way
to copy executable code on ARM platforms, so let's make use of that here
rather than the unsafe plain memcpy that was previously used by
sram_exec_copy. Now sram_exec_copy will move the code to "dst" and
return an address that is guaranteed to be safely callable.
In the future, architectures hoping to make use of the sram-exec
functionality must define an fncpy macro just as ARM has done to
guarantee or check for safe copying to executable memory before allowing
the arch to select CONFIG_SRAM_EXEC.
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
28 lines
844 B
C
28 lines
844 B
C
/*
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* Generic SRAM Driver Interface
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation version 2.
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*
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* This program is distributed "as is" WITHOUT ANY WARRANTY of any
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* kind, whether express or implied; without even the implied warranty
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* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#ifndef __LINUX_SRAM_H__
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#define __LINUX_SRAM_H__
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struct gen_pool;
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#ifdef CONFIG_SRAM_EXEC
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void *sram_exec_copy(struct gen_pool *pool, void *dst, void *src, size_t size);
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#else
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static inline void *sram_exec_copy(struct gen_pool *pool, void *dst, void *src,
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size_t size)
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{
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return NULL;
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}
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#endif /* CONFIG_SRAM_EXEC */
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#endif /* __LINUX_SRAM_H__ */
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