Commit 4e87ace9 authored by Sven Schnelle's avatar Sven Schnelle Committed by Helge Deller
Browse files

parisc: add support for patching multiple words 



add patch_text_multiple() which allows to patch multiple
text words in memory. This can be used to copy functions.

Signed-off-by: default avatarSven Schnelle <svens@stackframe.org>
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
parent 79c3ba32

arch/parisc/include/asm/patch.h

+3 −1
Original line number Diff line number Diff line
@@ -4,8 +4,10 @@ 


/* stop machine and patch kernel text */

void patch_text(void *addr, unsigned int insn);

void patch_text_multiple(void *addr, u32 *insn, unsigned int len);



/* patch kernel text with machine already stopped (e.g. in kgdb) */

void __patch_text(void *addr, unsigned int insn);

void __patch_text(void *addr, u32 insn);

void __patch_text_multiple(void *addr, u32 *insn, unsigned int len);



#endif

arch/parisc/kernel/patch.c

+59 −16
Original line number Diff line number Diff line
@@ -17,15 +17,18 @@ 


struct patch {

	void *addr;

	unsigned int insn;

	u32 *insn;

	unsigned int len;

};



static void __kprobes *patch_map(void *addr, int fixmap)

{

static DEFINE_RAW_SPINLOCK(patch_lock);



static void __kprobes *patch_map(void *addr, int fixmap, int *need_unmap)

	unsigned long uintaddr = (uintptr_t) addr;

	bool module = !core_kernel_text(uintaddr);

	struct page *page;



	*need_unmap = 0;

	if (module && IS_ENABLED(CONFIG_STRICT_MODULE_RWX))

		page = vmalloc_to_page(addr);

	else if (!module && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
@@ -33,6 +36,7 @@ static void __kprobes *patch_map(void *addr, int fixmap) 
	else

		return addr;



	*need_unmap = 1;

	set_fixmap(fixmap, page_to_phys(page));



	return (void *) (__fix_to_virt(fixmap) + (uintaddr & ~PAGE_MASK));
@@ -43,34 +47,73 @@ static void __kprobes patch_unmap(int fixmap) 
	clear_fixmap(fixmap);

}



void __kprobes __patch_text(void *addr, unsigned int insn)

void __kprobes __patch_text_multiple(void *addr, u32 *insn, unsigned int len)

{

	void *waddr = addr;

	int size;

	unsigned long start = (unsigned long)addr;

	unsigned long end = (unsigned long)addr + len;

	u32 *p, *fixmap;

	int mapped;



	/* Make sure we don't have any aliases in cache */

	flush_kernel_vmap_range(addr, len);

	flush_icache_range(start, end);



	p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &mapped);



	while (len >= 4) {

		*p++ = *insn++;

		addr += sizeof(u32);

		len -= sizeof(u32);

		if (len && offset_in_page(addr) == 0) {

			/*

			 * We're crossing a page boundary, so

			 * need to remap

			 */

			flush_kernel_vmap_range((void *)fixmap,

						(p-fixmap) * sizeof(*p));

			if (mapped)

				patch_unmap(FIX_TEXT_POKE0);

			p = fixmap = patch_map(addr, FIX_TEXT_POKE0, &mapped);

		}

	}



	waddr = patch_map(addr, FIX_TEXT_POKE0);

	*(u32 *)waddr = insn;

	size = sizeof(u32);

	flush_kernel_vmap_range(waddr, size);

	flush_kernel_vmap_range((void *)fixmap, (p-fixmap) * sizeof(*p));

	if (mapped)

		patch_unmap(FIX_TEXT_POKE0);

	flush_icache_range((uintptr_t)(addr),

			   (uintptr_t)(addr) + size);

	flush_icache_range(start, end);

}



void __kprobes __patch_text(void *addr, u32 insn)

{

	__patch_text_multiple(addr, &insn, sizeof(insn));

}



static int __kprobes patch_text_stop_machine(void *data)

{

	struct patch *patch = data;



	__patch_text(patch->addr, patch->insn);



	__patch_text_multiple(patch->addr, patch->insn, patch->len);

	return 0;

}



void __kprobes patch_text(void *addr, unsigned int insn)

{

	struct patch patch = {

		.addr = addr,

		.insn = &insn,

		.len = sizeof(insn),

	};



	stop_machine_cpuslocked(patch_text_stop_machine, &patch, NULL);

}



void __kprobes patch_text_multiple(void *addr, u32 *insn, unsigned int len)

{



	struct patch patch = {

		.addr = addr,

		.insn = insn,

		.len = len

	};



	stop_machine_cpuslocked(patch_text_stop_machine, &patch, NULL);