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authorPeter Zijlstra <peterz@infradead.org>2017-02-02 14:43:51 +0100
committerIngo Molnar <mingo@kernel.org>2017-03-27 10:20:28 +0200
commit9a93848fe787a53aec404e4e00d8f7f9bbdaebb4 (patch)
tree4e3b4f0b97838278a72f47a4b4ed2825610e1969 /arch/x86/um
parent1fa9d67a2f07893fc7e4a880867a6cbb81dda547 (diff)
downloadop-kernel-dev-9a93848fe787a53aec404e4e00d8f7f9bbdaebb4.zip
op-kernel-dev-9a93848fe787a53aec404e4e00d8f7f9bbdaebb4.tar.gz
x86/debug: Implement __WARN() using UD0
By using "UD0" for WARN()s we remove the function call and its possible __FILE__ and __LINE__ immediate arguments from the instruction stream. Total image size will not change much, what we win in the instruction stream we'll lose because of the __bug_table entries. Still, saves on I$ footprint and the total image size does go down a bit. text data filename 10702123 4530992 defconfig-build/vmlinux.orig 10682460 4530992 defconfig-build/vmlinux.patched (UML didn't seem to use GENERIC_BUG at all, so remove it) Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Weinberger <richard.weinberger@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/um')
-rw-r--r--arch/x86/um/Makefile2
-rw-r--r--arch/x86/um/bug.c21
2 files changed, 1 insertions, 22 deletions
diff --git a/arch/x86/um/Makefile b/arch/x86/um/Makefile
index e7e7055..76f17f0 100644
--- a/arch/x86/um/Makefile
+++ b/arch/x86/um/Makefile
@@ -8,7 +8,7 @@ else
BITS := 64
endif
-obj-y = bug.o bugs_$(BITS).o delay.o fault.o ldt.o \
+obj-y = bugs_$(BITS).o delay.o fault.o ldt.o \
ptrace_$(BITS).o ptrace_user.o setjmp_$(BITS).o signal.o \
stub_$(BITS).o stub_segv.o \
sys_call_table_$(BITS).o sysrq_$(BITS).o tls_$(BITS).o \
diff --git a/arch/x86/um/bug.c b/arch/x86/um/bug.c
deleted file mode 100644
index e8034e3..0000000
--- a/arch/x86/um/bug.c
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * Copyright (C) 2006 Jeff Dike (jdike@addtoit.com)
- * Licensed under the GPL V2
- */
-
-#include <linux/uaccess.h>
-
-/*
- * Mostly copied from i386/x86_86 - eliminated the eip < PAGE_OFFSET because
- * that's not relevant in skas mode.
- */
-
-int is_valid_bugaddr(unsigned long eip)
-{
- unsigned short ud2;
-
- if (probe_kernel_address((unsigned short __user *)eip, ud2))
- return 0;
-
- return ud2 == 0x0b0f;
-}
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