Revision dbe3ed1c078c193be34326728d494c5c4bc115e2 authored by Linus Torvalds on 19 September 2007, 18:37:14 UTC, committed by Linus Torvalds on 19 September 2007, 18:37:14 UTC
Randy Dunlap noticed an interesting "crashme" behaviour on his dual Prescott Xeon setup, where he gets page faults with the error code having a zero "user" bit, but the register state points back to user mode. This may be a CPU microcode buglet triggered by some strange instruction pattern that crashme generates, and loading a microcode update seems to possibly have fixed it. Regardless, we really should trust the register state more than the error code, since it's really the register state that determines whether we can actually send a signal, or whether we're in kernel mode and need to oops/kill the process in the case of a page fault. Cc: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 4f01a75
Kbuild
#
# Kbuild for top-level directory of the kernel
# This file takes care of the following:
# 1) Generate asm-offsets.h
# 2) Check for missing system calls
#####
# 1) Generate asm-offsets.h
#
offsets-file := include/asm-$(ARCH)/asm-offsets.h
always := $(offsets-file)
targets := $(offsets-file)
targets += arch/$(ARCH)/kernel/asm-offsets.s
clean-files := $(addprefix $(objtree)/,$(targets))
# Default sed regexp - multiline due to syntax constraints
define sed-y
"/^->/{s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; s:->::; p;}"
endef
# Override default regexp for specific architectures
sed-$(CONFIG_MIPS) := "/^@@@/{s/^@@@//; s/ \#.*\$$//; p;}"
quiet_cmd_offsets = GEN $@
define cmd_offsets
(set -e; \
echo "#ifndef __ASM_OFFSETS_H__"; \
echo "#define __ASM_OFFSETS_H__"; \
echo "/*"; \
echo " * DO NOT MODIFY."; \
echo " *"; \
echo " * This file was generated by Kbuild"; \
echo " *"; \
echo " */"; \
echo ""; \
sed -ne $(sed-y) $<; \
echo ""; \
echo "#endif" ) > $@
endef
# We use internal kbuild rules to avoid the "is up to date" message from make
arch/$(ARCH)/kernel/asm-offsets.s: arch/$(ARCH)/kernel/asm-offsets.c FORCE
$(Q)mkdir -p $(dir $@)
$(call if_changed_dep,cc_s_c)
$(obj)/$(offsets-file): arch/$(ARCH)/kernel/asm-offsets.s Kbuild
$(Q)mkdir -p $(dir $@)
$(call cmd,offsets)
#####
# 2) Check for missing system calls
#
quiet_cmd_syscalls = CALL $<
cmd_syscalls = $(CONFIG_SHELL) $< $(CC) $(c_flags)
PHONY += missing-syscalls
missing-syscalls: scripts/checksyscalls.sh FORCE
$(call cmd,syscalls)
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