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FlorentRevestrostedt
FlorentRevest
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rostedt
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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: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Florent Revest <revest@chromium.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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‎arch/arm64/Kconfig‎

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@@ -197,6 +197,8 @@ config ARM64
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!CC_OPTIMIZE_FOR_SIZE)
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select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \
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if DYNAMIC_FTRACE_WITH_ARGS
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select HAVE_SAMPLE_FTRACE_DIRECT
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select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
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select HAVE_EFFICIENT_UNALIGNED_ACCESS
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select HAVE_FAST_GUP
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select HAVE_FTRACE_MCOUNT_RECORD

‎samples/ftrace/ftrace-direct-modify.c‎

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@@ -2,7 +2,9 @@
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#include <linux/module.h>
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#include <linux/kthread.h>
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#include <linux/ftrace.h>
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#ifndef CONFIG_ARM64
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#include <asm/asm-offsets.h>
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#endif
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extern void my_direct_func1(void);
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extern void my_direct_func2(void);
@@ -96,6 +98,38 @@ asm (
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#endif /* CONFIG_S390 */
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#ifdef CONFIG_ARM64
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asm (
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" .pushsection .text, \"ax\", @progbits\n"
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" .type my_tramp1, @function\n"
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" .globl my_tramp1\n"
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" my_tramp1:"
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" bti c\n"
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" sub sp, sp, #16\n"
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" stp x9, x30, [sp]\n"
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" bl my_direct_func1\n"
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" ldp x30, x9, [sp]\n"
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" add sp, sp, #16\n"
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" ret x9\n"
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" .size my_tramp1, .-my_tramp1\n"
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" .type my_tramp2, @function\n"
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" .globl my_tramp2\n"
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" my_tramp2:"
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" bti c\n"
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" sub sp, sp, #16\n"
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" stp x9, x30, [sp]\n"
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" bl my_direct_func2\n"
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" ldp x30, x9, [sp]\n"
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" add sp, sp, #16\n"
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" ret x9\n"
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" .size my_tramp2, .-my_tramp2\n"
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" .popsection\n"
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);
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#endif /* CONFIG_ARM64 */
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#ifdef CONFIG_LOONGARCH
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asm (

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

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@@ -2,7 +2,9 @@
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#include <linux/module.h>
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#include <linux/kthread.h>
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#include <linux/ftrace.h>
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#ifndef CONFIG_ARM64
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#include <asm/asm-offsets.h>
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#endif
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extern void my_direct_func1(unsigned long ip);
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extern void my_direct_func2(unsigned long ip);
@@ -103,6 +105,44 @@ asm (
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#endif /* CONFIG_S390 */
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#ifdef CONFIG_ARM64
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asm (
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" .pushsection .text, \"ax\", @progbits\n"
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" .type my_tramp1, @function\n"
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" .globl my_tramp1\n"
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" my_tramp1:"
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" bti c\n"
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" sub sp, sp, #32\n"
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" stp x9, x30, [sp]\n"
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" str x0, [sp, #16]\n"
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" mov x0, x30\n"
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" bl my_direct_func1\n"
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" ldp x30, x9, [sp]\n"
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" ldr x0, [sp, #16]\n"
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" add sp, sp, #32\n"
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" ret x9\n"
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" .size my_tramp1, .-my_tramp1\n"
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" .type my_tramp2, @function\n"
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" .globl my_tramp2\n"
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" my_tramp2:"
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" bti c\n"
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" sub sp, sp, #32\n"
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" stp x9, x30, [sp]\n"
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" str x0, [sp, #16]\n"
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" mov x0, x30\n"
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" bl my_direct_func2\n"
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" ldp x30, x9, [sp]\n"
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" ldr x0, [sp, #16]\n"
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" add sp, sp, #32\n"
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" ret x9\n"
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" .size my_tramp2, .-my_tramp2\n"
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" .popsection\n"
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);
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#endif /* CONFIG_ARM64 */
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#ifdef CONFIG_LOONGARCH
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#include <asm/asm.h>
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‎samples/ftrace/ftrace-direct-multi.c‎

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@@ -4,7 +4,9 @@
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#include <linux/mm.h> /* for handle_mm_fault() */
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#include <linux/ftrace.h>
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#include <linux/sched/stat.h>
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#ifndef CONFIG_ARM64
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#include <asm/asm-offsets.h>
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#endif
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extern void my_direct_func(unsigned long ip);
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@@ -66,6 +68,29 @@ asm (
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#endif /* CONFIG_S390 */
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#ifdef CONFIG_ARM64
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asm (
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" .pushsection .text, \"ax\", @progbits\n"
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" .type my_tramp, @function\n"
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" .globl my_tramp\n"
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" my_tramp:"
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" bti c\n"
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" sub sp, sp, #32\n"
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" stp x9, x30, [sp]\n"
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" str x0, [sp, #16]\n"
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" mov x0, x30\n"
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" bl my_direct_func\n"
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" ldp x30, x9, [sp]\n"
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" ldr x0, [sp, #16]\n"
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" add sp, sp, #32\n"
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" ret x9\n"
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" .size my_tramp, .-my_tramp\n"
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" .popsection\n"
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);
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#endif /* CONFIG_ARM64 */
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#ifdef CONFIG_LOONGARCH
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#include <asm/asm.h>

‎samples/ftrace/ftrace-direct-too.c‎

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@@ -3,7 +3,9 @@
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#include <linux/mm.h> /* for handle_mm_fault() */
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#include <linux/ftrace.h>
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#ifndef CONFIG_ARM64
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#include <asm/asm-offsets.h>
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#endif
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extern void my_direct_func(struct vm_area_struct *vma, unsigned long address,
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unsigned int flags, struct pt_regs *regs);
@@ -72,6 +74,30 @@ asm (
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#endif /* CONFIG_S390 */
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#ifdef CONFIG_ARM64
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asm (
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" .pushsection .text, \"ax\", @progbits\n"
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" .type my_tramp, @function\n"
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" .globl my_tramp\n"
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" my_tramp:"
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" bti c\n"
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" sub sp, sp, #48\n"
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" stp x9, x30, [sp]\n"
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" stp x0, x1, [sp, #16]\n"
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" stp x2, x3, [sp, #32]\n"
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" bl my_direct_func\n"
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" ldp x30, x9, [sp]\n"
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" ldp x0, x1, [sp, #16]\n"
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" ldp x2, x3, [sp, #32]\n"
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" add sp, sp, #48\n"
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" ret x9\n"
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" .size my_tramp, .-my_tramp\n"
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" .popsection\n"
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);
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#endif /* CONFIG_ARM64 */
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#ifdef CONFIG_LOONGARCH
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asm (

‎samples/ftrace/ftrace-direct.c‎

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@@ -3,7 +3,9 @@
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#include <linux/sched.h> /* for wake_up_process() */
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#include <linux/ftrace.h>
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#ifndef CONFIG_ARM64
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#include <asm/asm-offsets.h>
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#endif
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extern void my_direct_func(struct task_struct *p);
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@@ -63,6 +65,28 @@ asm (
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#endif /* CONFIG_S390 */
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#ifdef CONFIG_ARM64
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asm (
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" .pushsection .text, \"ax\", @progbits\n"
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" .type my_tramp, @function\n"
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" .globl my_tramp\n"
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" my_tramp:"
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" bti c\n"
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" sub sp, sp, #32\n"
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" stp x9, x30, [sp]\n"
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" str x0, [sp, #16]\n"
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" bl my_direct_func\n"
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" ldp x30, x9, [sp]\n"
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" ldr x0, [sp, #16]\n"
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" add sp, sp, #32\n"
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" ret x9\n"
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" .size my_tramp, .-my_tramp\n"
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" .popsection\n"
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);
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#endif /* CONFIG_ARM64 */
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#ifdef CONFIG_LOONGARCH
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asm (

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