Commit 8c3526fb authored by Florent Revest's avatar Florent Revest Committed by Steven Rostedt (Google)
Browse files

arm64: ftrace: Add direct call trampoline samples support 

The ftrace samples need per-architecture trampoline implementations
to save and restore argument registers around the calls to
my_direct_func* and to restore polluted registers (eg: x30).

These samples also include <asm/asm-offsets.h> which, on arm64, is not
necessary and redefines previously defined macros (resulting in
warnings) so these includes are guarded by !CONFIG_ARM64.

Link: https://lkml.kernel.org/r/20230427140700.625241-3-revest@chromium.org



Reviewed-by: default avatarMark Rutland <mark.rutland@arm.com>
Tested-by: default avatarMark Rutland <mark.rutland@arm.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarFlorent Revest <revest@chromium.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 8564c315

arch/arm64/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -197,6 +197,8 @@ config ARM64 
		    !CC_OPTIMIZE_FOR_SIZE)

	select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \

		if DYNAMIC_FTRACE_WITH_ARGS

	select HAVE_SAMPLE_FTRACE_DIRECT

	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI

	select HAVE_EFFICIENT_UNALIGNED_ACCESS

	select HAVE_FAST_GUP

	select HAVE_FTRACE_MCOUNT_RECORD

samples/ftrace/ftrace-direct-modify.c

+34 −0
Original line number Diff line number Diff line
@@ -2,7 +2,9 @@ 
#include <linux/module.h>

#include <linux/kthread.h>

#include <linux/ftrace.h>

#ifndef CONFIG_ARM64

#include <asm/asm-offsets.h>

#endif



extern void my_direct_func1(void);

extern void my_direct_func2(void);
@@ -96,6 +98,38 @@ asm ( 


#endif /* CONFIG_S390 */



#ifdef CONFIG_ARM64



asm (

"	.pushsection    .text, \"ax\", @progbits\n"

"	.type		my_tramp1, @function\n"

"	.globl		my_tramp1\n"

"   my_tramp1:"

"	bti	c\n"

"	sub	sp, sp, #16\n"

"	stp	x9, x30, [sp]\n"

"	bl	my_direct_func1\n"

"	ldp	x30, x9, [sp]\n"

"	add	sp, sp, #16\n"

"	ret	x9\n"

"	.size		my_tramp1, .-my_tramp1\n"



"	.type		my_tramp2, @function\n"

"	.globl		my_tramp2\n"

"   my_tramp2:"

"	bti	c\n"

"	sub	sp, sp, #16\n"

"	stp	x9, x30, [sp]\n"

"	bl	my_direct_func2\n"

"	ldp	x30, x9, [sp]\n"

"	add	sp, sp, #16\n"

"	ret	x9\n"

"	.size		my_tramp2, .-my_tramp2\n"

"	.popsection\n"

);



#endif /* CONFIG_ARM64 */



#ifdef CONFIG_LOONGARCH



asm (

samples/ftrace/ftrace-direct-multi-modify.c

+40 −0
Original line number Diff line number Diff line
@@ -2,7 +2,9 @@ 
#include <linux/module.h>

#include <linux/kthread.h>

#include <linux/ftrace.h>

#ifndef CONFIG_ARM64

#include <asm/asm-offsets.h>

#endif



extern void my_direct_func1(unsigned long ip);

extern void my_direct_func2(unsigned long ip);
@@ -103,6 +105,44 @@ asm ( 


#endif /* CONFIG_S390 */



#ifdef CONFIG_ARM64



asm (

"	.pushsection    .text, \"ax\", @progbits\n"

"	.type		my_tramp1, @function\n"

"	.globl		my_tramp1\n"

"   my_tramp1:"

"	bti	c\n"

"	sub	sp, sp, #32\n"

"	stp	x9, x30, [sp]\n"

"	str	x0, [sp, #16]\n"

"	mov	x0, x30\n"

"	bl	my_direct_func1\n"

"	ldp	x30, x9, [sp]\n"

"	ldr	x0, [sp, #16]\n"

"	add	sp, sp, #32\n"

"	ret	x9\n"

"	.size		my_tramp1, .-my_tramp1\n"



"	.type		my_tramp2, @function\n"

"	.globl		my_tramp2\n"

"   my_tramp2:"

"	bti	c\n"

"	sub	sp, sp, #32\n"

"	stp	x9, x30, [sp]\n"

"	str	x0, [sp, #16]\n"

"	mov	x0, x30\n"

"	bl	my_direct_func2\n"

"	ldp	x30, x9, [sp]\n"

"	ldr	x0, [sp, #16]\n"

"	add	sp, sp, #32\n"

"	ret	x9\n"

"	.size		my_tramp2, .-my_tramp2\n"

"	.popsection\n"

);



#endif /* CONFIG_ARM64 */



#ifdef CONFIG_LOONGARCH

#include <asm/asm.h>

samples/ftrace/ftrace-direct-multi.c

+25 −0
Original line number Diff line number Diff line
@@ -4,7 +4,9 @@ 
#include <linux/mm.h> /* for handle_mm_fault() */

#include <linux/ftrace.h>

#include <linux/sched/stat.h>

#ifndef CONFIG_ARM64

#include <asm/asm-offsets.h>

#endif



extern void my_direct_func(unsigned long ip);
@@ -66,6 +68,29 @@ asm ( 


#endif /* CONFIG_S390 */



#ifdef CONFIG_ARM64



asm (

"	.pushsection	.text, \"ax\", @progbits\n"

"	.type		my_tramp, @function\n"

"	.globl		my_tramp\n"

"   my_tramp:"

"	bti	c\n"

"	sub	sp, sp, #32\n"

"	stp	x9, x30, [sp]\n"

"	str	x0, [sp, #16]\n"

"	mov	x0, x30\n"

"	bl	my_direct_func\n"

"	ldp	x30, x9, [sp]\n"

"	ldr	x0, [sp, #16]\n"

"	add	sp, sp, #32\n"

"	ret	x9\n"

"	.size		my_tramp, .-my_tramp\n"

"	.popsection\n"

);



#endif /* CONFIG_ARM64 */



#ifdef CONFIG_LOONGARCH



#include <asm/asm.h>

samples/ftrace/ftrace-direct-too.c

+26 −0
Original line number Diff line number Diff line
@@ -3,7 +3,9 @@ 


#include <linux/mm.h> /* for handle_mm_fault() */

#include <linux/ftrace.h>

#ifndef CONFIG_ARM64

#include <asm/asm-offsets.h>

#endif



extern void my_direct_func(struct vm_area_struct *vma, unsigned long address,

			   unsigned int flags, struct pt_regs *regs);
@@ -72,6 +74,30 @@ asm ( 


#endif /* CONFIG_S390 */



#ifdef CONFIG_ARM64



asm (

"	.pushsection	.text, \"ax\", @progbits\n"

"	.type		my_tramp, @function\n"

"	.globl		my_tramp\n"

"   my_tramp:"

"	bti	c\n"

"	sub	sp, sp, #48\n"

"	stp	x9, x30, [sp]\n"

"	stp	x0, x1, [sp, #16]\n"

"	stp	x2, x3, [sp, #32]\n"

"	bl	my_direct_func\n"

"	ldp	x30, x9, [sp]\n"

"	ldp	x0, x1, [sp, #16]\n"

"	ldp	x2, x3, [sp, #32]\n"

"	add	sp, sp, #48\n"

"	ret	x9\n"

"	.size		my_tramp, .-my_tramp\n"

"	.popsection\n"

);



#endif /* CONFIG_ARM64 */



#ifdef CONFIG_LOONGARCH



asm (