Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fix from Will Deacon: - Implement a basic static call trampoline to fix CFI failures with the generic implementation * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: Use static call trampolines when kCFI is enabled

Linus Torvalds committed 7 months ago

Commit 441c63f2 parents 60d9212 54ac9ff5 files · +57 −0Browse files

Unified · Split

5 files

arch/arm64/Kconfig +1 −0
arch/arm64/include/asm/static_call.h +31 −0
arch/arm64/kernel/Makefile +1 −0
arch/arm64/kernel/static_call.c +23 −0
arch/arm64/kernel/vmlinux.lds.S +1 −0

arch/arm64/Kconfig+1−0

@@ -252,6 +252,7 @@ config ARM64 · 251 unmodified lines
252	select HAVE_RSEQ	252	select HAVE_RSEQ
253	select HAVE_RUST if RUSTC_SUPPORTS_ARM64	253	select HAVE_RUST if RUSTC_SUPPORTS_ARM64
254	select HAVE_STACKPROTECTOR	254	select HAVE_STACKPROTECTOR
		255	select HAVE_STATIC_CALL if CFI
255	select HAVE_SYSCALL_TRACEPOINTS	256	select HAVE_SYSCALL_TRACEPOINTS
256	select HAVE_KPROBES	257	select HAVE_KPROBES
257	select HAVE_KRETPROBES	258	select HAVE_KRETPROBES

arch/arm64/include/asm/static_call.h+31−0

@@ -0,0 +1,31 @@
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	#ifndef _ASM_STATIC_CALL_H
	3	#define _ASM_STATIC_CALL_H
	4
	5	#define __ARCH_DEFINE_STATIC_CALL_TRAMP(name, target) \
	6	asm(" .pushsection .static_call.text, \"ax\" \n" \
	7	" .align 4 \n" \
	8	" .globl " name " \n" \
	9	name ": \n" \
	10	" hint 34 /* BTI C */ \n" \
	11	" adrp x16, 1f \n" \
	12	" ldr x16, [x16, :lo12:1f] \n" \
	13	" br x16 \n" \
	14	" .type " name ", %function \n" \
	15	" .size " name ", . - " name " \n" \
	16	" .popsection \n" \
	17	" .pushsection .rodata, \"a\" \n" \
	18	" .align 3 \n" \
	19	"1: .quad " target " \n" \
	20	" .popsection \n")
	21
	22	#define ARCH_DEFINE_STATIC_CALL_TRAMP(name, func) \
	23	__ARCH_DEFINE_STATIC_CALL_TRAMP(STATIC_CALL_TRAMP_STR(name), #func)
	24
	25	#define ARCH_DEFINE_STATIC_CALL_NULL_TRAMP(name) \
	26	ARCH_DEFINE_STATIC_CALL_TRAMP(name, __static_call_return0)
	27
	28	#define ARCH_DEFINE_STATIC_CALL_RET0_TRAMP(name) \
	29	ARCH_DEFINE_STATIC_CALL_TRAMP(name, __static_call_return0)
	30
	31	#endif /* _ASM_STATIC_CALL_H */

arch/arm64/kernel/Makefile+1−0

@@ -46,6 +46,7 @@ obj-$(CONFIG_MODULES) += module.o module-plts.o · 45 unmodified lines
46	obj-$(CONFIG_PERF_EVENTS) += perf_regs.o perf_callchain.o	46	obj-$(CONFIG_PERF_EVENTS) += perf_regs.o perf_callchain.o
47	obj-$(CONFIG_HARDLOCKUP_DETECTOR_PERF) += watchdog_hld.o	47	obj-$(CONFIG_HARDLOCKUP_DETECTOR_PERF) += watchdog_hld.o
48	obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o	48	obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
		49	obj-$(CONFIG_HAVE_STATIC_CALL) += static_call.o
49	obj-$(CONFIG_CPU_PM) += sleep.o suspend.o	50	obj-$(CONFIG_CPU_PM) += sleep.o suspend.o
50	obj-$(CONFIG_KGDB) += kgdb.o	51	obj-$(CONFIG_KGDB) += kgdb.o
51	obj-$(CONFIG_EFI) += efi.o efi-rt-wrapper.o	52	obj-$(CONFIG_EFI) += efi.o efi-rt-wrapper.o

arch/arm64/kernel/static_call.c+23−0

@@ -0,0 +1,23 @@
	1	// SPDX-License-Identifier: GPL-2.0
	2	#include <linux/static_call.h>
	3	#include <linux/memory.h>
	4	#include <asm/text-patching.h>
	5
	6	void arch_static_call_transform(void site, void tramp, void *func, bool tail)
	7	{
	8	u64 literal;
	9	int ret;
	10
	11	if (!func)
	12	func = __static_call_return0;
	13
	14	/* decode the instructions to discover the literal address */
	15	literal = ALIGN_DOWN((u64)tramp + 4, SZ_4K) +
	16	aarch64_insn_adrp_get_offset(le32_to_cpup(tramp + 4)) +
	17	8 * aarch64_insn_decode_immediate(AARCH64_INSN_IMM_12,
	18	le32_to_cpup(tramp + 8));
	19
	20	ret = aarch64_insn_write_literal_u64((void *)literal, (u64)func);
	21	WARN_ON_ONCE(ret);
	22	}
	23	EXPORT_SYMBOL_GPL(arch_static_call_transform);

arch/arm64/kernel/vmlinux.lds.S+1−0

@@ -191,6 +191,7 @@ SECTIONS · 190 unmodified lines
191	LOCK_TEXT	191	LOCK_TEXT
192	KPROBES_TEXT	192	KPROBES_TEXT
193	HYPERVISOR_TEXT	193	HYPERVISOR_TEXT
		194	STATIC_CALL_TEXT
194	*(.gnu.warning)	195	*(.gnu.warning)
195	}	196	}
196		197