From mboxrd@z Thu Jan  1 00:00:00 1970
From: peterz at infradead.org (Peter Zijlstra)
Date: Thu, 9 May 2019 11:27:38 +0200
Subject: [PATCH 2/4] x86/kprobes: Fix frame pointer annotations
In-Reply-To: <20190509081431.GO2589@hirez.programming.kicks-ass.net>
References: <20190508074901.982470324@infradead.org>
 <20190508080612.721269814@infradead.org>
 <20190508115416.nblx7c2kocidpytm@treble>
 <20190508120416.GL2589@hirez.programming.kicks-ass.net>
 <20190508124248.u5ukpbhnh4wpiccq@treble>
 <20190508153907.GM2589@hirez.programming.kicks-ass.net>
 <20190508184848.qerg3flv3ej3xsev@treble>
 <20190509102030.dfa62e058f09d0d8cbdd6053@kernel.org>
 <20190509081431.GO2589@hirez.programming.kicks-ass.net>
Message-ID: <20190509092738.GK2650@hirez.programming.kicks-ass.net>

On Thu, May 09, 2019 at 10:14:31AM +0200, Peter Zijlstra wrote:
> struct ftrace_regs_stack {
> 	ftrace_func_t func;
> 	unsigned long parent_ip;
> };
> 
> void ftrace_regs_handler(struct pr_regs *regs)
> {
> 	struct ftrace_regs_stack *st = (void *)regs->sp;
> 	ftrace_func_t func = st->func;
> 
> 	regs->sp += sizeof(long); /* pop func */
> 
> 	func(regs->ip, st->parent_ip, function_trace_op, regs);
> }

Alternatively we can add things like:

static inline unsigned long int3_emulate_pop(struct pt_regs *regs)
{
	unsigned long val = *(unsigned long *)regs->sp;
	regs->sp += sizeof(unsigned long);
	return val;
}

And do:

	ftrace_func_t func = (void *)int3_emulate_pop(regs);

From mboxrd@z Thu Jan  1 00:00:00 1970
From: peterz@infradead.org (Peter Zijlstra)
Date: Thu, 9 May 2019 11:27:38 +0200
Subject: [PATCH 2/4] x86/kprobes: Fix frame pointer annotations
In-Reply-To: <20190509081431.GO2589@hirez.programming.kicks-ass.net>
References: <20190508074901.982470324@infradead.org>
 <20190508080612.721269814@infradead.org>
 <20190508115416.nblx7c2kocidpytm@treble>
 <20190508120416.GL2589@hirez.programming.kicks-ass.net>
 <20190508124248.u5ukpbhnh4wpiccq@treble>
 <20190508153907.GM2589@hirez.programming.kicks-ass.net>
 <20190508184848.qerg3flv3ej3xsev@treble>
 <20190509102030.dfa62e058f09d0d8cbdd6053@kernel.org>
 <20190509081431.GO2589@hirez.programming.kicks-ass.net>
Message-ID: <20190509092738.GK2650@hirez.programming.kicks-ass.net>
Content-Type: text/plain; charset="UTF-8"
Message-ID: <20190509092738.wzWvapqmx_wZv2q5q3vjL04VTWr9sdlsyw13KE_Q3IQ@z>

On Thu, May 09, 2019@10:14:31AM +0200, Peter Zijlstra wrote:
> struct ftrace_regs_stack {
> 	ftrace_func_t func;
> 	unsigned long parent_ip;
> };
> 
> void ftrace_regs_handler(struct pr_regs *regs)
> {
> 	struct ftrace_regs_stack *st = (void *)regs->sp;
> 	ftrace_func_t func = st->func;
> 
> 	regs->sp += sizeof(long); /* pop func */
> 
> 	func(regs->ip, st->parent_ip, function_trace_op, regs);
> }

Alternatively we can add things like:

static inline unsigned long int3_emulate_pop(struct pt_regs *regs)
{
	unsigned long val = *(unsigned long *)regs->sp;
	regs->sp += sizeof(unsigned long);
	return val;
}

And do:

	ftrace_func_t func = (void *)int3_emulate_pop(regs);