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	Several architectures support text patching, but they name the header files that declare patching functions differently. Make all such headers consistently named text-patching.h and add an empty header in asm-generic for architectures that do not support text patching. Link: https://lkml.kernel.org/r/20241023162711.2579610-4-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Tested-by: kdevops <kdevops@lists.linux.dev> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Brian Cain <bcain@quicinc.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Song Liu <song@kernel.org> Cc: Stafford Horne <shorne@gmail.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
		
			
				
	
	
		
			128 lines
		
	
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			128 lines
		
	
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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#include <linux/kernel.h>
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#include <linux/spinlock.h>
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#include <linux/kprobes.h>
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#include <linux/mm.h>
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#include <linux/stop_machine.h>
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#include <asm/cacheflush.h>
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#include <asm/fixmap.h>
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#include <asm/smp_plat.h>
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#include <asm/opcodes.h>
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#include <asm/text-patching.h>
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struct patch {
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	void *addr;
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	unsigned int insn;
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};
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#ifdef CONFIG_MMU
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static DEFINE_RAW_SPINLOCK(patch_lock);
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static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags)
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{
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	unsigned int uintaddr = (uintptr_t) addr;
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	bool module = !core_kernel_text(uintaddr);
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	struct page *page;
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	if (module && IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
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		page = vmalloc_to_page(addr);
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	else if (!module && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
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		page = virt_to_page(addr);
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	else
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		return addr;
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	if (flags)
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		raw_spin_lock_irqsave(&patch_lock, *flags);
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	set_fixmap(fixmap, page_to_phys(page));
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	return (void *) (__fix_to_virt(fixmap) + (uintaddr & ~PAGE_MASK));
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}
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static void __kprobes patch_unmap(int fixmap, unsigned long *flags)
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{
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	clear_fixmap(fixmap);
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	if (flags)
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		raw_spin_unlock_irqrestore(&patch_lock, *flags);
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}
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#else
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static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags)
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{
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	return addr;
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}
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static void __kprobes patch_unmap(int fixmap, unsigned long *flags) { }
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#endif
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void __kprobes __patch_text_real(void *addr, unsigned int insn, bool remap)
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{
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	bool thumb2 = IS_ENABLED(CONFIG_THUMB2_KERNEL);
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	unsigned int uintaddr = (uintptr_t) addr;
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	bool twopage = false;
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	unsigned long flags;
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	void *waddr = addr;
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	int size;
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	if (remap)
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		waddr = patch_map(addr, FIX_TEXT_POKE0, &flags);
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	if (thumb2 && __opcode_is_thumb16(insn)) {
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		*(u16 *)waddr = __opcode_to_mem_thumb16(insn);
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		size = sizeof(u16);
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	} else if (thumb2 && (uintaddr & 2)) {
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		u16 first = __opcode_thumb32_first(insn);
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		u16 second = __opcode_thumb32_second(insn);
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		u16 *addrh0 = waddr;
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		u16 *addrh1 = waddr + 2;
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		twopage = (uintaddr & ~PAGE_MASK) == PAGE_SIZE - 2;
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		if (twopage && remap)
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			addrh1 = patch_map(addr + 2, FIX_TEXT_POKE1, NULL);
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		*addrh0 = __opcode_to_mem_thumb16(first);
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		*addrh1 = __opcode_to_mem_thumb16(second);
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		if (twopage && addrh1 != addr + 2) {
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			flush_kernel_vmap_range(addrh1, 2);
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			patch_unmap(FIX_TEXT_POKE1, NULL);
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		}
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		size = sizeof(u32);
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	} else {
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		if (thumb2)
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			insn = __opcode_to_mem_thumb32(insn);
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		else
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			insn = __opcode_to_mem_arm(insn);
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		*(u32 *)waddr = insn;
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		size = sizeof(u32);
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	}
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	if (waddr != addr) {
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		flush_kernel_vmap_range(waddr, twopage ? size / 2 : size);
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		patch_unmap(FIX_TEXT_POKE0, &flags);
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	}
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	flush_icache_range((uintptr_t)(addr),
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			   (uintptr_t)(addr) + size);
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}
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static int __kprobes patch_text_stop_machine(void *data)
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{
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	struct patch *patch = data;
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	__patch_text(patch->addr, patch->insn);
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	return 0;
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}
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void __kprobes patch_text(void *addr, unsigned int insn)
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{
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	struct patch patch = {
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		.addr = addr,
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		.insn = insn,
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	};
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	stop_machine_cpuslocked(patch_text_stop_machine, &patch, NULL);
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}
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