mirror of
				https://github.com/torvalds/linux.git
				synced 2025-11-04 02:30:34 +02:00 
			
		
		
		
	Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
	  If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
            If both the HTTP and HTTPS versions
            return 200 OK and serve the same content:
              Replace HTTP with HTTPS.
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Link: https://lore.kernel.org/r/20200713104453.33414-1-grandmaster@al2klimov.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
		
	
			
		
			
				
	
	
		
			132 lines
		
	
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			132 lines
		
	
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * SRAM protect-exec region helper functions
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 *
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 * Copyright (C) 2017 Texas Instruments Incorporated - https://www.ti.com/
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 *	Dave Gerlach
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License version 2 as
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 * published by the Free Software Foundation.
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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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#include <linux/device.h>
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#include <linux/genalloc.h>
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#include <linux/mm.h>
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#include <linux/sram.h>
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#include <asm/fncpy.h>
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#include <asm/set_memory.h>
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#include "sram.h"
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static DEFINE_MUTEX(exec_pool_list_mutex);
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static LIST_HEAD(exec_pool_list);
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int sram_check_protect_exec(struct sram_dev *sram, struct sram_reserve *block,
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			    struct sram_partition *part)
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{
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	unsigned long base = (unsigned long)part->base;
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	unsigned long end = base + block->size;
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	if (!PAGE_ALIGNED(base) || !PAGE_ALIGNED(end)) {
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		dev_err(sram->dev,
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			"SRAM pool marked with 'protect-exec' is not page aligned and will not be created.\n");
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		return -ENOMEM;
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	}
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	return 0;
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}
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int sram_add_protect_exec(struct sram_partition *part)
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{
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	mutex_lock(&exec_pool_list_mutex);
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	list_add_tail(&part->list, &exec_pool_list);
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	mutex_unlock(&exec_pool_list_mutex);
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	return 0;
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}
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/**
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 * sram_exec_copy - copy data to a protected executable region of sram
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 *
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 * @pool: struct gen_pool retrieved that is part of this sram
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 * @dst: Destination address for the copy, that must be inside pool
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 * @src: Source address for the data to copy
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 * @size: Size of copy to perform, which starting from dst, must reside in pool
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 *
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 * Return: Address for copied data that can safely be called through function
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 *	   pointer, or NULL if problem.
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 *
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 * This helper function allows sram driver to act as central control location
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 * of 'protect-exec' pools which are normal sram pools but are always set
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 * read-only and executable except when copying data to them, at which point
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 * they are set to read-write non-executable, to make sure no memory is
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 * writeable and executable at the same time. This region must be page-aligned
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 * and is checked during probe, otherwise page attribute manipulation would
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 * not be possible. Care must be taken to only call the returned address as
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 * dst address is not guaranteed to be safely callable.
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 *
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 * NOTE: This function uses the fncpy macro to move code to the executable
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 * region. Some architectures have strict requirements for relocating
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 * executable code, so fncpy is a macro that must be defined by any arch
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 * making use of this functionality that guarantees a safe copy of exec
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 * data and returns a safe address that can be called as a C function
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 * pointer.
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 */
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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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	struct sram_partition *part = NULL, *p;
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	unsigned long base;
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	int pages;
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	void *dst_cpy;
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	int ret;
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	mutex_lock(&exec_pool_list_mutex);
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	list_for_each_entry(p, &exec_pool_list, list) {
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		if (p->pool == pool)
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			part = p;
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	}
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	mutex_unlock(&exec_pool_list_mutex);
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	if (!part)
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		return NULL;
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	if (!gen_pool_has_addr(pool, (unsigned long)dst, size))
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		return NULL;
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	base = (unsigned long)part->base;
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	pages = PAGE_ALIGN(size) / PAGE_SIZE;
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	mutex_lock(&part->lock);
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	ret = set_memory_nx((unsigned long)base, pages);
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	if (ret)
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		goto error_out;
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	ret = set_memory_rw((unsigned long)base, pages);
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	if (ret)
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		goto error_out;
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	dst_cpy = fncpy(dst, src, size);
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	ret = set_memory_ro((unsigned long)base, pages);
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	if (ret)
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		goto error_out;
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	ret = set_memory_x((unsigned long)base, pages);
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	if (ret)
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		goto error_out;
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	mutex_unlock(&part->lock);
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	return dst_cpy;
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error_out:
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	mutex_unlock(&part->lock);
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	return NULL;
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}
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EXPORT_SYMBOL_GPL(sram_exec_copy);
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