linux-next/arch/arm/kernel/patch.c
Mike Rapoport (Microsoft) 0c3beacf68 asm-generic: introduce text-patching.h
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>
2024-11-07 14:25:15 -08:00

129 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/kprobes.h>
#include <linux/mm.h>
#include <linux/stop_machine.h>
#include <asm/cacheflush.h>
#include <asm/fixmap.h>
#include <asm/smp_plat.h>
#include <asm/opcodes.h>
#include <asm/text-patching.h>
struct patch {
void *addr;
unsigned int insn;
};
#ifdef CONFIG_MMU
static DEFINE_RAW_SPINLOCK(patch_lock);
static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags)
{
unsigned int uintaddr = (uintptr_t) addr;
bool module = !core_kernel_text(uintaddr);
struct page *page;
if (module && IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
page = vmalloc_to_page(addr);
else if (!module && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
page = virt_to_page(addr);
else
return addr;
if (flags)
raw_spin_lock_irqsave(&patch_lock, *flags);
set_fixmap(fixmap, page_to_phys(page));
return (void *) (__fix_to_virt(fixmap) + (uintaddr & ~PAGE_MASK));
}
static void __kprobes patch_unmap(int fixmap, unsigned long *flags)
{
clear_fixmap(fixmap);
if (flags)
raw_spin_unlock_irqrestore(&patch_lock, *flags);
}
#else
static void __kprobes *patch_map(void *addr, int fixmap, unsigned long *flags)
{
return addr;
}
static void __kprobes patch_unmap(int fixmap, unsigned long *flags) { }
#endif
void __kprobes __patch_text_real(void *addr, unsigned int insn, bool remap)
{
bool thumb2 = IS_ENABLED(CONFIG_THUMB2_KERNEL);
unsigned int uintaddr = (uintptr_t) addr;
bool twopage = false;
unsigned long flags;
void *waddr = addr;
int size;
if (remap)
waddr = patch_map(addr, FIX_TEXT_POKE0, &flags);
if (thumb2 && __opcode_is_thumb16(insn)) {
*(u16 *)waddr = __opcode_to_mem_thumb16(insn);
size = sizeof(u16);
} else if (thumb2 && (uintaddr & 2)) {
u16 first = __opcode_thumb32_first(insn);
u16 second = __opcode_thumb32_second(insn);
u16 *addrh0 = waddr;
u16 *addrh1 = waddr + 2;
twopage = (uintaddr & ~PAGE_MASK) == PAGE_SIZE - 2;
if (twopage && remap)
addrh1 = patch_map(addr + 2, FIX_TEXT_POKE1, NULL);
*addrh0 = __opcode_to_mem_thumb16(first);
*addrh1 = __opcode_to_mem_thumb16(second);
if (twopage && addrh1 != addr + 2) {
flush_kernel_vmap_range(addrh1, 2);
patch_unmap(FIX_TEXT_POKE1, NULL);
}
size = sizeof(u32);
} else {
if (thumb2)
insn = __opcode_to_mem_thumb32(insn);
else
insn = __opcode_to_mem_arm(insn);
*(u32 *)waddr = insn;
size = sizeof(u32);
}
if (waddr != addr) {
flush_kernel_vmap_range(waddr, twopage ? size / 2 : size);
patch_unmap(FIX_TEXT_POKE0, &flags);
}
flush_icache_range((uintptr_t)(addr),
(uintptr_t)(addr) + size);
}
static int __kprobes patch_text_stop_machine(void *data)
{
struct patch *patch = data;
__patch_text(patch->addr, patch->insn);
return 0;
}
void __kprobes patch_text(void *addr, unsigned int insn)
{
struct patch patch = {
.addr = addr,
.insn = insn,
};
stop_machine_cpuslocked(patch_text_stop_machine, &patch, NULL);
}