Stable Archive on lore.kernel.org
 help / color / Atom feed
* FAILED: patch "[PATCH] x86/purgatory: Use CFLAGS_REMOVE rather than reset" failed to apply to 4.4-stable tree
@ 2019-08-13 18:40 gregkh
  0 siblings, 0 replies; only message in thread
From: gregkh @ 2019-08-13 18:40 UTC (permalink / raw)
  To: ndesaulniers, peterz, tglx, vaibhavrustagi; +Cc: stable


The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b059f801a937d164e03b33c1848bb3dca67c0b04 Mon Sep 17 00:00:00 2001
From: Nick Desaulniers <ndesaulniers@google.com>
Date: Wed, 7 Aug 2019 15:15:33 -0700
Subject: [PATCH] x86/purgatory: Use CFLAGS_REMOVE rather than reset
 KBUILD_CFLAGS

KBUILD_CFLAGS is very carefully built up in the top level Makefile,
particularly when cross compiling or using different build tools.
Resetting KBUILD_CFLAGS via := assignment is an antipattern.

The comment above the reset mentions that -pg is problematic.  Other
Makefiles use `CFLAGS_REMOVE_file.o = $(CC_FLAGS_FTRACE)` when
CONFIG_FUNCTION_TRACER is set. Prefer that pattern to wiping out all of
the important KBUILD_CFLAGS then manually having to re-add them. Seems
also that __stack_chk_fail references are generated when using
CONFIG_STACKPROTECTOR or CONFIG_STACKPROTECTOR_STRONG.

Fixes: 8fc5b4d4121c ("purgatory: core purgatory functionality")
Reported-by: Vaibhav Rustagi <vaibhavrustagi@google.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vaibhav Rustagi <vaibhavrustagi@google.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190807221539.94583-2-ndesaulniers@google.com

diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile
index 91ef244026d2..8901a1f89cf5 100644
--- a/arch/x86/purgatory/Makefile
+++ b/arch/x86/purgatory/Makefile
@@ -20,11 +20,34 @@ KCOV_INSTRUMENT := n
 
 # Default KBUILD_CFLAGS can have -pg option set when FTRACE is enabled. That
 # in turn leaves some undefined symbols like __fentry__ in purgatory and not
-# sure how to relocate those. Like kexec-tools, use custom flags.
-
-KBUILD_CFLAGS := -fno-strict-aliasing -Wall -Wstrict-prototypes -fno-zero-initialized-in-bss -fno-builtin -ffreestanding -c -Os -mcmodel=large
-KBUILD_CFLAGS += -m$(BITS)
-KBUILD_CFLAGS += $(call cc-option,-fno-PIE)
+# sure how to relocate those.
+ifdef CONFIG_FUNCTION_TRACER
+CFLAGS_REMOVE_sha256.o		+= $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_purgatory.o	+= $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_string.o		+= $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_kexec-purgatory.o	+= $(CC_FLAGS_FTRACE)
+endif
+
+ifdef CONFIG_STACKPROTECTOR
+CFLAGS_REMOVE_sha256.o		+= -fstack-protector
+CFLAGS_REMOVE_purgatory.o	+= -fstack-protector
+CFLAGS_REMOVE_string.o		+= -fstack-protector
+CFLAGS_REMOVE_kexec-purgatory.o	+= -fstack-protector
+endif
+
+ifdef CONFIG_STACKPROTECTOR_STRONG
+CFLAGS_REMOVE_sha256.o		+= -fstack-protector-strong
+CFLAGS_REMOVE_purgatory.o	+= -fstack-protector-strong
+CFLAGS_REMOVE_string.o		+= -fstack-protector-strong
+CFLAGS_REMOVE_kexec-purgatory.o	+= -fstack-protector-strong
+endif
+
+ifdef CONFIG_RETPOLINE
+CFLAGS_REMOVE_sha256.o		+= $(RETPOLINE_CFLAGS)
+CFLAGS_REMOVE_purgatory.o	+= $(RETPOLINE_CFLAGS)
+CFLAGS_REMOVE_string.o		+= $(RETPOLINE_CFLAGS)
+CFLAGS_REMOVE_kexec-purgatory.o	+= $(RETPOLINE_CFLAGS)
+endif
 
 $(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE
 		$(call if_changed,ld)


^ permalink raw reply	[flat|nested] only message in thread

only message in thread, back to index

Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-08-13 18:40 FAILED: patch "[PATCH] x86/purgatory: Use CFLAGS_REMOVE rather than reset" failed to apply to 4.4-stable tree gregkh

Stable Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/stable/0 stable/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 stable stable/ https://lore.kernel.org/stable \
		stable@vger.kernel.org stable@archiver.kernel.org
	public-inbox-index stable


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.stable


AGPL code for this site: git clone https://public-inbox.org/ public-inbox