Commit 9772b7f0 authored by Will Deacon's avatar Will Deacon
Browse files

Merge branch 'for-next/stacktrace' into for-next/core 

* for-next/stacktrace:
  arm64: move PAC masks to <asm/pointer_auth.h>
  arm64: use XPACLRI to strip PAC
  arm64: avoid redundant PAC stripping in __builtin_return_address()
  arm64: stacktrace: always inline core stacktrace functions
  arm64: stacktrace: move dump functions to end of file
  arm64: stacktrace: recover return address for first entry
parents 9651f00e de1702f6

arch/arm64/Kconfig

+14 −0
Original line number Diff line number Diff line
@@ -366,6 +366,20 @@ config ARCH_PROC_KCORE_TEXT 
config BROKEN_GAS_INST

	def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n)



config BUILTIN_RETURN_ADDRESS_STRIPS_PAC

	bool

	# Clang's __builtin_return_adddress() strips the PAC since 12.0.0

	# https://reviews.llvm.org/D75044

	default y if CC_IS_CLANG && (CLANG_VERSION >= 120000)

	# GCC's __builtin_return_address() strips the PAC since 11.1.0,

	# and this was backported to 10.2.0, 9.4.0, 8.5.0, but not earlier

	# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94891

	default y if CC_IS_GCC && (GCC_VERSION >= 110100)

	default y if CC_IS_GCC && (GCC_VERSION >= 100200) && (GCC_VERSION < 110000)

	default y if CC_IS_GCC && (GCC_VERSION >=  90400) && (GCC_VERSION < 100000)

	default y if CC_IS_GCC && (GCC_VERSION >=  80500) && (GCC_VERSION <  90000)

	default n



config KASAN_SHADOW_OFFSET

	hex

	depends on KASAN_GENERIC || KASAN_SW_TAGS

arch/arm64/include/asm/compiler.h

+25 −11
Original line number Diff line number Diff line
@@ -8,19 +8,33 @@ 
#define ARM64_ASM_PREAMBLE

#endif



/*

 * The EL0/EL1 pointer bits used by a pointer authentication code.

 * This is dependent on TBI0/TBI1 being enabled, or bits 63:56 would also apply.

 */

#define ptrauth_user_pac_mask()		GENMASK_ULL(54, vabits_actual)

#define ptrauth_kernel_pac_mask()	GENMASK_ULL(63, vabits_actual)

#define xpaclri(ptr)							\

({									\

	register unsigned long __xpaclri_ptr asm("x30") = (ptr);	\

									\

	asm(								\

	ARM64_ASM_PREAMBLE						\

	"	hint	#7\n"						\

	: "+r" (__xpaclri_ptr));					\

									\

	__xpaclri_ptr;							\

})



/* Valid for EL0 TTBR0 and EL1 TTBR1 instruction pointers */

#define ptrauth_clear_pac(ptr)						\

	((ptr & BIT_ULL(55)) ? (ptr | ptrauth_kernel_pac_mask()) :	\

			       (ptr & ~ptrauth_user_pac_mask()))

#ifdef CONFIG_ARM64_PTR_AUTH_KERNEL

#define ptrauth_strip_kernel_insn_pac(ptr)	xpaclri(ptr)

#else

#define ptrauth_strip_kernel_insn_pac(ptr)	(ptr)

#endif



#ifdef CONFIG_ARM64_PTR_AUTH

#define ptrauth_strip_user_insn_pac(ptr)	xpaclri(ptr)

#else

#define ptrauth_strip_user_insn_pac(ptr)	(ptr)

#endif



#if !defined(CONFIG_BUILTIN_RETURN_ADDRESS_STRIPS_PAC)

#define __builtin_return_address(val)					\

	(void *)(ptrauth_clear_pac((unsigned long)__builtin_return_address(val)))

	(void *)(ptrauth_strip_kernel_insn_pac((unsigned long)__builtin_return_address(val)))

#endif



#endif /* __ASM_COMPILER_H */

arch/arm64/include/asm/pointer_auth.h

+7 −6
Original line number Diff line number Diff line
@@ -10,6 +10,13 @@ 
#include <asm/memory.h>

#include <asm/sysreg.h>



/*

 * The EL0/EL1 pointer bits used by a pointer authentication code.

 * This is dependent on TBI0/TBI1 being enabled, or bits 63:56 would also apply.

 */

#define ptrauth_user_pac_mask()		GENMASK_ULL(54, vabits_actual)

#define ptrauth_kernel_pac_mask()	GENMASK_ULL(63, vabits_actual)



#define PR_PAC_ENABLED_KEYS_MASK                                               \

	(PR_PAC_APIAKEY | PR_PAC_APIBKEY | PR_PAC_APDAKEY | PR_PAC_APDBKEY)
@@ -97,11 +104,6 @@ extern int ptrauth_set_enabled_keys(struct task_struct *tsk, unsigned long keys, 
				    unsigned long enabled);

extern int ptrauth_get_enabled_keys(struct task_struct *tsk);



static inline unsigned long ptrauth_strip_insn_pac(unsigned long ptr)

{

	return ptrauth_clear_pac(ptr);

}



static __always_inline void ptrauth_enable(void)

{

	if (!system_supports_address_auth())
@@ -133,7 +135,6 @@ static __always_inline void ptrauth_enable(void) 
#define ptrauth_prctl_reset_keys(tsk, arg)	(-EINVAL)

#define ptrauth_set_enabled_keys(tsk, keys, enabled)	(-EINVAL)

#define ptrauth_get_enabled_keys(tsk)	(-EINVAL)

#define ptrauth_strip_insn_pac(lr)	(lr)

#define ptrauth_suspend_exit()

#define ptrauth_thread_init_user()

#define ptrauth_thread_switch_user(tsk)

arch/arm64/kernel/crash_core.c

+1 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <asm/cpufeature.h>

#include <asm/memory.h>

#include <asm/pgtable-hwdef.h>

#include <asm/pointer_auth.h>



static inline u64 get_tcr_el1_t1sz(void);

arch/arm64/kernel/perf_callchain.c

+1 −1
Original line number Diff line number Diff line
@@ -38,7 +38,7 @@ user_backtrace(struct frame_tail __user *tail, 
	if (err)

		return NULL;



	lr = ptrauth_strip_insn_pac(buftail.lr);

	lr = ptrauth_strip_user_insn_pac(buftail.lr);



	perf_callchain_store(entry, lr);