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https://github.com/torvalds/linux
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dfad83cb71
Provide hooks to intercept bad usages of virt_to_phys() and __pa_symbol() throughout the kernel. To make this possible, we need to rename the current implement of virt_to_phys() into __virt_to_phys_nodebug() and wrap it around depending on CONFIG_DEBUG_VIRTUAL. A similar thing is needed for __pa_symbol() which is now aliased to __phys_addr_symbol() whose implementation is either the direct return of RELOC_HIDE or goes through the debug version. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
57 lines
1.4 KiB
C
57 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/bug.h>
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#include <linux/export.h>
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#include <linux/types.h>
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#include <linux/mmdebug.h>
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#include <linux/mm.h>
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#include <asm/sections.h>
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#include <asm/io.h>
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#include <asm/page.h>
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#include <asm/dma.h>
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static inline bool __debug_virt_addr_valid(unsigned long x)
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{
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/* high_memory does not get immediately defined, and there
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* are early callers of __pa() against PAGE_OFFSET
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*/
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if (!high_memory && x >= PAGE_OFFSET)
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return true;
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if (high_memory && x >= PAGE_OFFSET && x < (unsigned long)high_memory)
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return true;
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/*
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* MAX_DMA_ADDRESS is a virtual address that may not correspond to an
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* actual physical address. Enough code relies on
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* virt_to_phys(MAX_DMA_ADDRESS) that we just need to work around it
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* and always return true.
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*/
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if (x == MAX_DMA_ADDRESS)
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return true;
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return false;
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}
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phys_addr_t __virt_to_phys(volatile const void *x)
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{
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WARN(!__debug_virt_addr_valid((unsigned long)x),
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"virt_to_phys used for non-linear address: %pK (%pS)\n",
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x, x);
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return __virt_to_phys_nodebug(x);
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}
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EXPORT_SYMBOL(__virt_to_phys);
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phys_addr_t __phys_addr_symbol(unsigned long x)
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{
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/* This is bounds checking against the kernel image only.
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* __pa_symbol should only be used on kernel symbol addresses.
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*/
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VIRTUAL_BUG_ON(x < (unsigned long)_text ||
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x > (unsigned long)_end);
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return __pa_symbol_nodebug(x);
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}
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EXPORT_SYMBOL(__phys_addr_symbol);
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