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SubjectRe: [PATCH] ARM: kprobes: Make __kretprobe_trampoline as a pure asm function
On Thu, 24 Mar 2022 at 14:34, Ard Biesheuvel <ardb@kernel.org> wrote:
>
> --- a/arch/arm/probes/kprobes/core.c
> +++ b/arch/arm/probes/kprobes/core.c
> @@ -377,7 +377,7 @@ void __naked __kprobes __kretprobe_trampoline(void)
> {
> __asm__ __volatile__ (
> #ifdef CONFIG_FRAME_POINTER
> - "ldr lr, =__kretprobe_trampoline \n\t"
> + "ldr lr, .L__kretprobe_trampoline \n\t"
> /* __kretprobe_trampoline makes a framepointer on pt_regs. */
> #ifdef CONFIG_CC_IS_CLANG
> "stmdb sp, {sp, lr, pc} \n\t"
> @@ -407,6 +407,11 @@ void __naked __kprobes __kretprobe_trampoline(void)
> "bx lr \n\t"
> #else
> "mov pc, lr \n\t"
> +#endif
> +#ifdef CONFIG_FRAME_POINTER
> + ".align 2 \n\t"
> + ".L__kretprobe_trampoline: \n\t"
> + ".long __kretprobe_trampoline \n\t"
> #endif
> : : : "memory");
> }
>
>

Pardon the copy/paste error.

> What about the below?

was meant to refer to the diff above.


> On Thu, 24 Mar 2022 at 14:23, Masami Hiramatsu <mhiramat@kernel.org> wrote:
> >
> > On Thu, 24 Mar 2022 15:21:08 +0900
> > Masami Hiramatsu <mhiramat@kernel.org> wrote:
> >
> > > Hi,
> > >
> > > I found a better solution for this issue from Ard :-)
> > >
> > > https://lore.kernel.org/all/20220203082204.1176734-6-ardb@kernel.org/T/#u
> > >
> > > I should use mov_l instead of ldr for loading the symbol address.
> >
> > Hm, these macros are only for the pure assembly file (.S), so we have to
> > split this in a asm file to use that.
> >
>
>
> What about the below?

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