Files insn.[c|h] containt some functions used for instruction patching. In order to reuse the instruction encoder/decoder, move the patching utilities to their own file.
Signed-off-by: Julien Thierry <jthie...@redhat.com> --- arch/arm64/include/asm/insn.h | 5 - arch/arm64/include/asm/patching.h | 13 +++ arch/arm64/kernel/Makefile | 2 +- arch/arm64/kernel/ftrace.c | 1 + arch/arm64/kernel/insn.c | 149 +----------------------------- arch/arm64/kernel/jump_label.c | 1 + arch/arm64/kernel/patching.c | 148 +++++++++++++++++++++++++++++ arch/arm64/kernel/traps.c | 1 + 8 files changed, 168 insertions(+), 152 deletions(-) create mode 100644 arch/arm64/include/asm/patching.h create mode 100644 arch/arm64/kernel/patching.c diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h index 4ebb9c054ccc..7437b7e7e7eb 100644 --- a/arch/arm64/include/asm/insn.h +++ b/arch/arm64/include/asm/insn.h @@ -379,8 +379,6 @@ static inline bool aarch64_insn_is_adr_adrp(u32 insn) return aarch64_insn_is_adr(insn) || aarch64_insn_is_adrp(insn); } -int aarch64_insn_read(void *addr, u32 *insnp); -int aarch64_insn_write(void *addr, u32 insn); enum aarch64_insn_encoding_class aarch64_get_insn_class(u32 insn); bool aarch64_insn_uses_literal(u32 insn); bool aarch64_insn_is_branch(u32 insn); @@ -487,9 +485,6 @@ u32 aarch64_insn_gen_prefetch(enum aarch64_insn_register base, s32 aarch64_get_branch_offset(u32 insn); u32 aarch64_set_branch_offset(u32 insn, s32 offset); -int aarch64_insn_patch_text_nosync(void *addr, u32 insn); -int aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt); - s32 aarch64_insn_adrp_get_offset(u32 insn); u32 aarch64_insn_adrp_set_offset(u32 insn, s32 offset); diff --git a/arch/arm64/include/asm/patching.h b/arch/arm64/include/asm/patching.h new file mode 100644 index 000000000000..6bf5adc56295 --- /dev/null +++ b/arch/arm64/include/asm/patching.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef __ASM_PATCHING_H +#define __ASM_PATCHING_H + +#include <linux/types.h> + +int aarch64_insn_read(void *addr, u32 *insnp); +int aarch64_insn_write(void *addr, u32 insn); + +int aarch64_insn_patch_text_nosync(void *addr, u32 insn); +int aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt); + +#endif /* __ASM_PATCHING_H */ diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index ed65576ce710..790af8c69338 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -17,7 +17,7 @@ obj-y := debug-monitors.o entry.o irq.o fpsimd.o \ return_address.o cpuinfo.o cpu_errata.o \ cpufeature.o alternative.o cacheinfo.o \ smp.o smp_spin_table.o topology.o smccc-call.o \ - syscall.o proton-pack.o idreg-override.o + syscall.o proton-pack.o idreg-override.o patching.o targets += efi-entry.o diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index 86a5cf9bc19a..fd7993f0c9c4 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -15,6 +15,7 @@ #include <asm/debug-monitors.h> #include <asm/ftrace.h> #include <asm/insn.h> +#include <asm/patching.h> #ifdef CONFIG_DYNAMIC_FTRACE /* diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c index 6c0de2f60ea9..952e7d6fe60e 100644 --- a/arch/arm64/kernel/insn.c +++ b/arch/arm64/kernel/insn.c @@ -7,21 +7,14 @@ */ #include <linux/bitops.h> #include <linux/bug.h> -#include <linux/compiler.h> -#include <linux/kernel.h> -#include <linux/mm.h> -#include <linux/smp.h> -#include <linux/spinlock.h> -#include <linux/stop_machine.h> +#include <linux/printk.h> +#include <linux/sizes.h> #include <linux/types.h> -#include <linux/uaccess.h> -#include <asm/cacheflush.h> #include <asm/debug-monitors.h> -#include <asm/fixmap.h> +#include <asm/errno.h> #include <asm/insn.h> #include <asm/kprobes.h> -#include <asm/sections.h> #define AARCH64_INSN_SF_BIT BIT(31) #define AARCH64_INSN_N_BIT BIT(22) @@ -83,81 +76,6 @@ bool aarch64_insn_is_branch_imm(u32 insn) aarch64_insn_is_bcond(insn)); } -static DEFINE_RAW_SPINLOCK(patch_lock); - -static bool is_exit_text(unsigned long addr) -{ - /* discarded with init text/data */ - return system_state < SYSTEM_RUNNING && - addr >= (unsigned long)__exittext_begin && - addr < (unsigned long)__exittext_end; -} - -static bool is_image_text(unsigned long addr) -{ - return core_kernel_text(addr) || is_exit_text(addr); -} - -static void __kprobes *patch_map(void *addr, int fixmap) -{ - unsigned long uintaddr = (uintptr_t) addr; - bool image = is_image_text(uintaddr); - struct page *page; - - if (image) - page = phys_to_page(__pa_symbol(addr)); - else if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) - page = vmalloc_to_page(addr); - else - return addr; - - BUG_ON(!page); - return (void *)set_fixmap_offset(fixmap, page_to_phys(page) + - (uintaddr & ~PAGE_MASK)); -} - -static void __kprobes patch_unmap(int fixmap) -{ - clear_fixmap(fixmap); -} -/* - * In ARMv8-A, A64 instructions have a fixed length of 32 bits and are always - * little-endian. - */ -int __kprobes aarch64_insn_read(void *addr, u32 *insnp) -{ - int ret; - __le32 val; - - ret = copy_from_kernel_nofault(&val, addr, AARCH64_INSN_SIZE); - if (!ret) - *insnp = le32_to_cpu(val); - - return ret; -} - -static int __kprobes __aarch64_insn_write(void *addr, __le32 insn) -{ - void *waddr = addr; - unsigned long flags = 0; - int ret; - - raw_spin_lock_irqsave(&patch_lock, flags); - waddr = patch_map(addr, FIX_TEXT_POKE0); - - ret = copy_to_kernel_nofault(waddr, &insn, AARCH64_INSN_SIZE); - - patch_unmap(FIX_TEXT_POKE0); - raw_spin_unlock_irqrestore(&patch_lock, flags); - - return ret; -} - -int __kprobes aarch64_insn_write(void *addr, u32 insn) -{ - return __aarch64_insn_write(addr, cpu_to_le32(insn)); -} - bool __kprobes aarch64_insn_uses_literal(u32 insn) { /* ldr/ldrsw (literal), prfm */ @@ -187,67 +105,6 @@ bool __kprobes aarch64_insn_is_branch(u32 insn) aarch64_insn_is_bcond(insn); } -int __kprobes aarch64_insn_patch_text_nosync(void *addr, u32 insn) -{ - u32 *tp = addr; - int ret; - - /* A64 instructions must be word aligned */ - if ((uintptr_t)tp & 0x3) - return -EINVAL; - - ret = aarch64_insn_write(tp, insn); - if (ret == 0) - __flush_icache_range((uintptr_t)tp, - (uintptr_t)tp + AARCH64_INSN_SIZE); - - return ret; -} - -struct aarch64_insn_patch { - void **text_addrs; - u32 *new_insns; - int insn_cnt; - atomic_t cpu_count; -}; - -static int __kprobes aarch64_insn_patch_text_cb(void *arg) -{ - int i, ret = 0; - struct aarch64_insn_patch *pp = arg; - - /* The first CPU becomes master */ - if (atomic_inc_return(&pp->cpu_count) == 1) { - for (i = 0; ret == 0 && i < pp->insn_cnt; i++) - ret = aarch64_insn_patch_text_nosync(pp->text_addrs[i], - pp->new_insns[i]); - /* Notify other processors with an additional increment. */ - atomic_inc(&pp->cpu_count); - } else { - while (atomic_read(&pp->cpu_count) <= num_online_cpus()) - cpu_relax(); - isb(); - } - - return ret; -} - -int __kprobes aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt) -{ - struct aarch64_insn_patch patch = { - .text_addrs = addrs, - .new_insns = insns, - .insn_cnt = cnt, - .cpu_count = ATOMIC_INIT(0), - }; - - if (cnt <= 0) - return -EINVAL; - - return stop_machine_cpuslocked(aarch64_insn_patch_text_cb, &patch, - cpu_online_mask); -} - static int __kprobes aarch64_get_imm_shift_mask(enum aarch64_insn_imm_type type, u32 *maskp, int *shiftp) { diff --git a/arch/arm64/kernel/jump_label.c b/arch/arm64/kernel/jump_label.c index 9a8a0ae1e75f..fc98037e1220 100644 --- a/arch/arm64/kernel/jump_label.c +++ b/arch/arm64/kernel/jump_label.c @@ -8,6 +8,7 @@ #include <linux/kernel.h> #include <linux/jump_label.h> #include <asm/insn.h> +#include <asm/patching.h> void arch_jump_label_transform(struct jump_entry *entry, enum jump_label_type type) diff --git a/arch/arm64/kernel/patching.c b/arch/arm64/kernel/patching.c new file mode 100644 index 000000000000..9d050e33901b --- /dev/null +++ b/arch/arm64/kernel/patching.c @@ -0,0 +1,148 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/smp.h> +#include <linux/spinlock.h> +#include <linux/stop_machine.h> +#include <linux/uaccess.h> + +#include <asm/cacheflush.h> +#include <asm/fixmap.h> +#include <asm/kprobes.h> +#include <asm/sections.h> + +static DEFINE_RAW_SPINLOCK(patch_lock); + +static bool is_exit_text(unsigned long addr) +{ + /* discarded with init text/data */ + return system_state < SYSTEM_RUNNING && + addr >= (unsigned long)__exittext_begin && + addr < (unsigned long)__exittext_end; +} + +static bool is_image_text(unsigned long addr) +{ + return core_kernel_text(addr) || is_exit_text(addr); +} + +static void __kprobes *patch_map(void *addr, int fixmap) +{ + unsigned long uintaddr = (uintptr_t) addr; + bool image = is_image_text(uintaddr); + struct page *page; + + if (image) + page = phys_to_page(__pa_symbol(addr)); + else if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) + page = vmalloc_to_page(addr); + else + return addr; + + BUG_ON(!page); + return (void *)set_fixmap_offset(fixmap, page_to_phys(page) + + (uintaddr & ~PAGE_MASK)); +} + +static void __kprobes patch_unmap(int fixmap) +{ + clear_fixmap(fixmap); +} +/* + * In ARMv8-A, A64 instructions have a fixed length of 32 bits and are always + * little-endian. + */ +int __kprobes aarch64_insn_read(void *addr, u32 *insnp) +{ + int ret; + __le32 val; + + ret = copy_from_kernel_nofault(&val, addr, AARCH64_INSN_SIZE); + if (!ret) + *insnp = le32_to_cpu(val); + + return ret; +} + +static int __kprobes __aarch64_insn_write(void *addr, __le32 insn) +{ + void *waddr = addr; + unsigned long flags = 0; + int ret; + + raw_spin_lock_irqsave(&patch_lock, flags); + waddr = patch_map(addr, FIX_TEXT_POKE0); + + ret = copy_to_kernel_nofault(waddr, &insn, AARCH64_INSN_SIZE); + + patch_unmap(FIX_TEXT_POKE0); + raw_spin_unlock_irqrestore(&patch_lock, flags); + + return ret; +} + +int __kprobes aarch64_insn_write(void *addr, u32 insn) +{ + return __aarch64_insn_write(addr, cpu_to_le32(insn)); +} + +int __kprobes aarch64_insn_patch_text_nosync(void *addr, u32 insn) +{ + u32 *tp = addr; + int ret; + + /* A64 instructions must be word aligned */ + if ((uintptr_t)tp & 0x3) + return -EINVAL; + + ret = aarch64_insn_write(tp, insn); + if (ret == 0) + __flush_icache_range((uintptr_t)tp, + (uintptr_t)tp + AARCH64_INSN_SIZE); + + return ret; +} + +struct aarch64_insn_patch { + void **text_addrs; + u32 *new_insns; + int insn_cnt; + atomic_t cpu_count; +}; + +static int __kprobes aarch64_insn_patch_text_cb(void *arg) +{ + int i, ret = 0; + struct aarch64_insn_patch *pp = arg; + + /* The first CPU becomes master */ + if (atomic_inc_return(&pp->cpu_count) == 1) { + for (i = 0; ret == 0 && i < pp->insn_cnt; i++) + ret = aarch64_insn_patch_text_nosync(pp->text_addrs[i], + pp->new_insns[i]); + /* Notify other processors with an additional increment. */ + atomic_inc(&pp->cpu_count); + } else { + while (atomic_read(&pp->cpu_count) <= num_online_cpus()) + cpu_relax(); + isb(); + } + + return ret; +} + +int __kprobes aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt) +{ + struct aarch64_insn_patch patch = { + .text_addrs = addrs, + .new_insns = insns, + .insn_cnt = cnt, + .cpu_count = ATOMIC_INIT(0), + }; + + if (cnt <= 0) + return -EINVAL; + + return stop_machine_cpuslocked(aarch64_insn_patch_text_cb, &patch, + cpu_online_mask); +} diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index a05d34f0e82a..d7057e307bca 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -38,6 +38,7 @@ #include <asm/extable.h> #include <asm/insn.h> #include <asm/kprobes.h> +#include <asm/patching.h> #include <asm/traps.h> #include <asm/smp.h> #include <asm/stack_pointer.h> -- 2.25.4