On 2025/2/6 20:33, Peter Zijlstra wrote:
On Thu, Feb 06, 2025 at 01:13:28PM +0100, Peter Zijlstra wrote:
No, it just cleans up this utter trainwreck. I also noticed this is a
second (new) copy of this garbage. Clearly I didn't yell loud enough
last time and people didn't think to vomit when doing the copy/paste :/
Function will look something like:
unsigned long arch_ftrace_get_symaddr(unsigned long fentry_ip)
{
if (is_endbr(fentry_ip - ENDBR_INSN_SIZE))
fentry_op -= ENDBR_INSN_SIZE;
return fentry_ip;
}
Let me finish local build test before I push out.
Bah, still waiting for a LLVM build, but patch should be here:
git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git x86/ibt
I was supposed to merge this last cycle, but then akpm shat all over
arch/x86/kernel/alternative.c and we had to clean that up :/
Notably, this patch, not sure it applies out of order.
---
Subject: x86/ibt: Clean up is_endbr()
From: Peter Zijlstra <[email protected]>
Date: Mon Nov 27 09:58:06 CET 2023
Pretty much every caller of is_endbr() actually wants to test something at an
address and ends up doing get_kernel_nofault(). Fold the lot into a more
convenient helper.
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>
Acked-by: Andrii Nakryiko <[email protected]>
---
arch/x86/events/core.c | 2 +-
arch/x86/include/asm/ftrace.h | 17 +++--------------
arch/x86/include/asm/ibt.h | 5 +++--
arch/x86/kernel/alternative.c | 20 ++++++++++++++------
arch/x86/kernel/kprobes/core.c | 11 +----------
arch/x86/net/bpf_jit_comp.c | 4 ++--
kernel/trace/bpf_trace.c | 20 +++-----------------
7 files changed, 27 insertions(+), 52 deletions(-)
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2857,7 +2857,7 @@ static bool is_uprobe_at_func_entry(stru
return true;
/* endbr64 (64-bit only) */
- if (user_64bit_mode(regs) && is_endbr(*(u32 *)auprobe->insn))
+ if (user_64bit_mode(regs) && is_endbr((u32 *)auprobe->insn))
return true;
return false;
--- a/arch/x86/include/asm/ftrace.h
+++ b/arch/x86/include/asm/ftrace.h
@@ -2,6 +2,7 @@
#ifndef _ASM_X86_FTRACE_H
#define _ASM_X86_FTRACE_H
+#include "asm/ibt.h"
Then
https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/tree/arch/x86/include/asm/ftrace.h?h=x86/ibt#n17
# include <asm/ibt.h> --> This line can be removed ?
#include <asm/ptrace.h>
#ifdef CONFIG_FUNCTION_TRACER
@@ -36,21 +37,9 @@ static inline unsigned long ftrace_call_
static inline unsigned long arch_ftrace_get_symaddr(unsigned long fentry_ip)
{
