Commit 6c81fe79 authored by Larry Bassel's avatar Larry Bassel Committed by Catalin Marinas
Browse files

arm64: enable context tracking 



Make calls to ct_user_enter when the kernel is exited
and ct_user_exit when the kernel is entered (in el0_da,
el0_ia, el0_svc, el0_irq and all of the "error" paths).

These macros expand to function calls which will only work
properly if el0_sync and related code has been rearranged
(in a previous patch of this series).

The calls to ct_user_exit are made after hw debugging has been
enabled (enable_dbg_and_irq).

The call to ct_user_enter is made at the beginning of the
kernel_exit macro.

This patch is based on earlier work by Kevin Hilman.
Save/restore optimizations were also done by Kevin.

Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Reviewed-by: default avatarKevin Hilman <khilman@linaro.org>
Tested-by: default avatarKevin Hilman <khilman@linaro.org>
Signed-off-by: default avatarLarry Bassel <larry.bassel@linaro.org>
Signed-off-by: default avatarKevin Hilman <khilman@linaro.org>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 6ab6463a

arch/arm64/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -63,6 +63,7 @@ config ARM64 
	select RTC_LIB

	select SPARSE_IRQ

	select SYSCTL_EXCEPTION_TRACE

	select HAVE_CONTEXT_TRACKING

	help

	  ARM 64-bit (AArch64) Linux support.

arch/arm64/include/asm/thread_info.h

+4 −1
Original line number Diff line number Diff line
@@ -103,6 +103,7 @@ static inline struct thread_info *current_thread_info(void) 
#define TIF_NEED_RESCHED	1

#define TIF_NOTIFY_RESUME	2	/* callback before returning to user */

#define TIF_FOREIGN_FPSTATE	3	/* CPU's FP state is not current's */

#define TIF_NOHZ		7

#define TIF_SYSCALL_TRACE	8

#define TIF_SYSCALL_AUDIT	9

#define TIF_SYSCALL_TRACEPOINT	10
@@ -118,6 +119,7 @@ static inline struct thread_info *current_thread_info(void) 
#define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)

#define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)

#define _TIF_FOREIGN_FPSTATE	(1 << TIF_FOREIGN_FPSTATE)

#define _TIF_NOHZ		(1 << TIF_NOHZ)

#define _TIF_SYSCALL_TRACE	(1 << TIF_SYSCALL_TRACE)

#define _TIF_SYSCALL_AUDIT	(1 << TIF_SYSCALL_AUDIT)

#define _TIF_SYSCALL_TRACEPOINT	(1 << TIF_SYSCALL_TRACEPOINT)
@@ -128,7 +130,8 @@ static inline struct thread_info *current_thread_info(void) 
				 _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE)



#define _TIF_SYSCALL_WORK	(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \

				 _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP)

				 _TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \

				 _TIF_NOHZ)



#endif /* __KERNEL__ */

#endif /* __ASM_THREAD_INFO_H */

arch/arm64/kernel/entry.S

+36 −0
Original line number Diff line number Diff line
@@ -29,6 +29,32 @@ 
#include <asm/unistd.h>

#include <asm/unistd32.h>



/*

 * Context tracking subsystem.  Used to instrument transitions

 * between user and kernel mode.

 */

	.macro ct_user_exit, syscall = 0

#ifdef CONFIG_CONTEXT_TRACKING

	bl	context_tracking_user_exit

	.if \syscall == 1

	/*

	 * Save/restore needed during syscalls.  Restore syscall arguments from

	 * the values already saved on stack during kernel_entry.

	 */

	ldp	x0, x1, [sp]

	ldp	x2, x3, [sp, #S_X2]

	ldp	x4, x5, [sp, #S_X4]

	ldp	x6, x7, [sp, #S_X6]

	.endif

#endif

	.endm



	.macro ct_user_enter

#ifdef CONFIG_CONTEXT_TRACKING

	bl	context_tracking_user_enter

#endif

	.endm



/*

 * Bad Abort numbers

 *-----------------
@@ -91,6 +117,7 @@ 
	.macro	kernel_exit, el, ret = 0

	ldp	x21, x22, [sp, #S_PC]		// load ELR, SPSR

	.if	\el == 0

	ct_user_enter

	ldr	x23, [sp, #S_SP]		// load return stack pointer

	.endif

	.if	\ret
@@ -426,6 +453,7 @@ el0_da: 
	mrs	x26, far_el1

	// enable interrupts before calling the main handler

	enable_dbg_and_irq

	ct_user_exit

	bic	x0, x26, #(0xff << 56)

	mov	x1, x25

	mov	x2, sp
@@ -438,6 +466,7 @@ el0_ia: 
	mrs	x26, far_el1

	// enable interrupts before calling the main handler

	enable_dbg_and_irq

	ct_user_exit

	mov	x0, x26

	orr	x1, x25, #1 << 24		// use reserved ISS bit for instruction aborts

	mov	x2, sp
@@ -448,6 +477,7 @@ el0_fpsimd_acc: 
	 * Floating Point or Advanced SIMD access

	 */

	enable_dbg

	ct_user_exit

	mov	x0, x25

	mov	x1, sp

	adr	lr, ret_to_user
@@ -457,6 +487,7 @@ el0_fpsimd_exc: 
	 * Floating Point or Advanced SIMD exception

	 */

	enable_dbg

	ct_user_exit

	mov	x0, x25

	mov	x1, sp

	adr	lr, ret_to_user
@@ -479,6 +510,7 @@ el0_undef: 
	 */

	// enable interrupts before calling the main handler

	enable_dbg_and_irq

	ct_user_exit

	mov	x0, sp

	adr	lr, ret_to_user

	b	do_undefinstr
@@ -492,9 +524,11 @@ el0_dbg: 
	mov	x2, sp

	bl	do_debug_exception

	enable_dbg

	ct_user_exit

	b	ret_to_user

el0_inv:

	enable_dbg

	ct_user_exit

	mov	x0, sp

	mov	x1, #BAD_SYNC

	mrs	x2, esr_el1
@@ -511,6 +545,7 @@ el0_irq_naked: 
	bl	trace_hardirqs_off

#endif



	ct_user_exit

	irq_handler



#ifdef CONFIG_TRACE_IRQFLAGS
@@ -615,6 +650,7 @@ el0_svc: 
el0_svc_naked:					// compat entry point

	stp	x0, scno, [sp, #S_ORIG_X0]	// save the original x0 and syscall number

	enable_dbg_and_irq

	ct_user_exit 1



	ldr	x16, [tsk, #TI_FLAGS]		// check for syscall hooks

	tst	x16, #_TIF_SYSCALL_WORK

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