The patch titled
Generic BUG for x86-64
has been removed from the -mm tree. Its filename was
generic-bug-for-x86-64.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: Generic BUG for x86-64
From: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
This makes x86-64 use the generic BUG machinery. The most significant
The main advantage in using the generic BUG machinery for x86-64 is that the
inlined overhead of BUG is just the ud2a instruction; the file+line
information are no longer inlined into the instruction stream. This reduces
cache pollution.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Cc: Andi Kleen <ak@xxxxxx>
Cc: Hugh Dickens <hugh@xxxxxxxxxxx>
Cc: Michael Ellerman <michael@xxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
arch/x86_64/Kconfig | 5 +++
arch/x86_64/kernel/module.c | 5 ++-
arch/x86_64/kernel/traps.c | 36 +++++++----------------
arch/x86_64/kernel/vmlinux.lds.S | 2 +
include/asm-x86_64/bug.h | 44 ++++++++++++++---------------
5 files changed, 45 insertions(+), 47 deletions(-)
diff -puN arch/x86_64/Kconfig~generic-bug-for-x86-64 arch/x86_64/Kconfig
--- a/arch/x86_64/Kconfig~generic-bug-for-x86-64
+++ a/arch/x86_64/Kconfig
@@ -96,6 +96,11 @@ config AUDIT_ARCH
bool
default y
+config GENERIC_BUG
+ bool
+ default y
+ depends on BUG
+
source "init/Kconfig"
diff -puN arch/x86_64/kernel/module.c~generic-bug-for-x86-64 arch/x86_64/kernel/module.c
--- a/arch/x86_64/kernel/module.c~generic-bug-for-x86-64
+++ a/arch/x86_64/kernel/module.c
@@ -23,6 +23,7 @@
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/slab.h>
+#include <linux/bug.h>
#include <asm/system.h>
#include <asm/page.h>
@@ -173,10 +174,12 @@ int module_finalize(const Elf_Ehdr *hdr,
lseg, lseg + locks->sh_size,
tseg, tseg + text->sh_size);
}
- return 0;
+
+ return module_bug_finalize(hdr, sechdrs, me);
}
void module_arch_cleanup(struct module *mod)
{
alternatives_smp_module_del(mod);
+ module_bug_cleanup(mod);
}
diff -puN arch/x86_64/kernel/traps.c~generic-bug-for-x86-64 arch/x86_64/kernel/traps.c
--- a/arch/x86_64/kernel/traps.c~generic-bug-for-x86-64
+++ a/arch/x86_64/kernel/traps.c
@@ -31,6 +31,7 @@
#include <linux/kexec.h>
#include <linux/unwind.h>
#include <linux/uaccess.h>
+#include <linux/bug.h>
#include <asm/system.h>
#include <asm/io.h>
@@ -524,30 +525,15 @@ bad:
printk("\n");
}
-void handle_BUG(struct pt_regs *regs)
-{
- struct bug_frame f;
- long len;
- const char *prefix = "";
+int is_valid_bugaddr(unsigned long rip)
+{
+ unsigned short ud2;
- if (user_mode(regs))
- return;
- if (__copy_from_user(&f, (const void __user *) regs->rip,
- sizeof(struct bug_frame)))
- return;
- if (f.filename >= 0 ||
- f.ud2[0] != 0x0f || f.ud2[1] != 0x0b)
- return;
- len = __strnlen_user((char *)(long)f.filename, PATH_MAX) - 1;
- if (len < 0 || len >= PATH_MAX)
- f.filename = (int)(long)"unmapped filename";
- else if (len > 50) {
- f.filename += len - 50;
- prefix = "...";
- }
- printk("----------- [cut here ] --------- [please bite here ] ---------\n");
- printk(KERN_ALERT "Kernel BUG at %s%.50s:%d\n", prefix, (char *)(long)f.filename, f.line);
-}
+ if (__copy_from_user(&ud2, (const void __user *) rip, sizeof(ud2)))
+ return 0;
+
+ return ud2 == 0x0b0f;
+}
#ifdef CONFIG_BUG
void out_of_line_bug(void)
@@ -627,7 +613,9 @@ void die(const char * str, struct pt_reg
{
unsigned long flags = oops_begin();
- handle_BUG(regs);
+ if (!user_mode(regs))
+ report_bug(regs->rip);
+
__die(str, regs, err);
oops_end(flags);
do_exit(SIGSEGV);
diff -puN arch/x86_64/kernel/vmlinux.lds.S~generic-bug-for-x86-64 arch/x86_64/kernel/vmlinux.lds.S
--- a/arch/x86_64/kernel/vmlinux.lds.S~generic-bug-for-x86-64
+++ a/arch/x86_64/kernel/vmlinux.lds.S
@@ -51,6 +51,8 @@ SECTIONS
RODATA
+ BUG_TABLE
+
. = ALIGN(PAGE_SIZE); /* Align data segment to page size boundary */
/* Data */
.data : AT(ADDR(.data) - LOAD_OFFSET) {
diff -puN include/asm-x86_64/bug.h~generic-bug-for-x86-64 include/asm-x86_64/bug.h
--- a/include/asm-x86_64/bug.h~generic-bug-for-x86-64
+++ a/include/asm-x86_64/bug.h
@@ -1,30 +1,30 @@
#ifndef __ASM_X8664_BUG_H
#define __ASM_X8664_BUG_H 1
-#include <linux/stringify.h>
-
-/*
- * Tell the user there is some problem. The exception handler decodes
- * this frame.
- */
-struct bug_frame {
- unsigned char ud2[2];
- unsigned char push;
- signed int filename;
- unsigned char ret;
- unsigned short line;
-} __attribute__((packed));
-
#ifdef CONFIG_BUG
#define HAVE_ARCH_BUG
-/* We turn the bug frame into valid instructions to not confuse
- the disassembler. Thanks to Jan Beulich & Suresh Siddha
- for nice instruction selection.
- The magic numbers generate mov $64bitimm,%eax ; ret $offset. */
-#define BUG() \
- asm volatile( \
- "ud2 ; pushq $%c1 ; ret $%c0" :: \
- "i"(__LINE__), "i" (__FILE__))
+
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+#define BUG() \
+ do { \
+ asm volatile("1:\tud2\n" \
+ ".pushsection __bug_table,\"a\"\n" \
+ "2:\t.quad 1b, %c0\n" \
+ "\t.word %c1, 0\n" \
+ "\t.org 2b+%c2\n" \
+ ".popsection" \
+ : : "i" (__FILE__), "i" (__LINE__), \
+ "i" (sizeof(struct bug_entry))); \
+ for(;;) ; \
+ } while(0)
+#else
+#define BUG() \
+ do { \
+ asm volatile("ud2"); \
+ for(;;) ; \
+ } while(0)
+#endif
+
void out_of_line_bug(void);
#else
static inline void out_of_line_bug(void) { }
_
Patches currently in -mm which might be from jeremy@xxxxxxxx are
origin.patch
generic-bug-for-x86-64.patch
uml-add-generic-bug-support.patch
use-generic-bug-for-ppc.patch
fix-generic-warn_on-message.patch
convert-i386-pda-code-to-use-%fs.patch
time-uninline-jiffiesh-fix.patch
-
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