From: Peter Zijlstra <peterz@infradead.org>
Date: Thu, 7 Mar 2019 18:54:25 +0000 (+0100)
Subject: x86/uaccess, kcov: Disable stack protector
X-Git-Tag: v5.2-rc1~213^2~11
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=40ea97290b08be2e038b31cbb33097d1145e8169;p=users%2Fwilly%2Fxarray.git

x86/uaccess, kcov: Disable stack protector

New tooling noticed this mishap:

  kernel/kcov.o: warning: objtool: write_comp_data()+0x138: call to __stack_chk_fail() with UACCESS enabled
  kernel/kcov.o: warning: objtool: __sanitizer_cov_trace_pc()+0xd9: call to __stack_chk_fail() with UACCESS enabled

All the other instrumentation (KASAN,UBSAN) also have stack protector
disabled.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---

diff --git a/kernel/Makefile b/kernel/Makefile
index 6c57e78817da..62471e75a2b0 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -30,6 +30,7 @@ KCOV_INSTRUMENT_extable.o := n
 # Don't self-instrument.
 KCOV_INSTRUMENT_kcov.o := n
 KASAN_SANITIZE_kcov.o := n
+CFLAGS_kcov.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
 
 # cond_syscall is currently not LTO compatible
 CFLAGS_sys_ni.o = $(DISABLE_LTO)