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um: Preinclude include/linux/kern_levels.h

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The userspace part of UML uses the asm-offsets.h generator mechanism to
create definitions for UM_KERN_<LEVEL> that match the in-kernel
KERN_<LEVEL> constant definitions.

As of commit 04d2c8c83d ("printk: convert
the format for KERN_<LEVEL> to a 2 byte pattern"), KERN_<LEVEL> is no
longer expanded to the literal '"<LEVEL>"', but to '"\001" "LEVEL"', i.e.
it contains two parts.

However, the combo of DEFINE_STR() in
arch/x86/um/shared/sysdep/kernel-offsets.h and sed-y in Kbuild doesn't
support string literals consisting of multiple parts. Hence for all
UM_KERN_<LEVEL> definitions, only the SOH character is retained in the actual
definition, while the remainder ends up in the comment. E.g. in
include/generated/asm-offsets.h we get

    #define UM_KERN_INFO "\001" /* "6" KERN_INFO */

instead of

    #define UM_KERN_INFO "\001" "6" /* KERN_INFO */

This causes spurious '^A' output in some kernel messages:

    Calibrating delay loop... 4640.76 BogoMIPS (lpj=23203840)
    pid_max: default: 32768 minimum: 301
    Mount-cache hash table entries: 256
    ^AChecking that host ptys support output SIGIO...Yes
    ^AChecking that host ptys support SIGIO on close...No, enabling workaround
    ^AUsing 2.6 host AIO
    NET: Registered protocol family 16
    bio: create slab <bio-0> at 0
    Switching to clocksource itimer

To fix this:
  - Move the mapping from UM_KERN_<LEVEL> to KERN_<LEVEL> from
    arch/um/include/shared/common-offsets.h to
    arch/um/include/shared/user.h, which is preincluded for all userspace
    parts,
  - Preinclude include/linux/kern_levels.h for all userspace parts, to
    obtain the in-kernel KERN_<LEVEL> constant definitions. This doesn't
    violate the kernel/userspace separation, as include/linux/kern_levels.h
    is self-contained and doesn't expose any other kernel internals.
  - Remove the now unused STR() and DEFINE_STR() macros.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
This commit is contained in:
Geert Uytterhoeven 2012-08-16 20:15:05 +02:00 committed by Richard Weinberger
parent bbb35efcda
commit 9429ec96c2
4 changed files with 12 additions and 14 deletions
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10
arch/um/include/shared/common-offsets.h
View File

@ -7,16 +7,6 @@ DEFINE(UM_KERN_PAGE_MASK, PAGE_MASK);
DEFINE(UM_KERN_PAGE_SHIFT, PAGE_SHIFT);
DEFINE(UM_NSEC_PER_SEC, NSEC_PER_SEC);
DEFINE_STR(UM_KERN_EMERG, KERN_EMERG);
DEFINE_STR(UM_KERN_ALERT, KERN_ALERT);
DEFINE_STR(UM_KERN_CRIT, KERN_CRIT);
DEFINE_STR(UM_KERN_ERR, KERN_ERR);
DEFINE_STR(UM_KERN_WARNING, KERN_WARNING);
DEFINE_STR(UM_KERN_NOTICE, KERN_NOTICE);
DEFINE_STR(UM_KERN_INFO, KERN_INFO);
DEFINE_STR(UM_KERN_DEBUG, KERN_DEBUG);
DEFINE_STR(UM_KERN_CONT, KERN_CONT);
DEFINE(UM_ELF_CLASS, ELF_CLASS);
DEFINE(UM_ELFCLASS32, ELFCLASS32);
DEFINE(UM_ELFCLASS64, ELFCLASS64);

11
arch/um/include/shared/user.h
View File

@ -26,6 +26,17 @@
extern void panic(const char *fmt, ...)
__attribute__ ((format (printf, 1, 2)));
/* Requires preincluding include/linux/kern_levels.h */
#define UM_KERN_EMERG KERN_EMERG
#define UM_KERN_ALERT KERN_ALERT
#define UM_KERN_CRIT KERN_CRIT
#define UM_KERN_ERR KERN_ERR
#define UM_KERN_WARNING KERN_WARNING
#define UM_KERN_NOTICE KERN_NOTICE
#define UM_KERN_INFO KERN_INFO
#define UM_KERN_DEBUG KERN_DEBUG
#define UM_KERN_CONT KERN_CONT
#ifdef UML_CONFIG_PRINTK
extern int printk(const char *fmt, ...)
__attribute__ ((format (printf, 1, 2)));

2
arch/um/scripts/Makefile.rules
View File

@ -8,7 +8,7 @@ USER_OBJS += $(filter %_user.o,$(obj-y) $(obj-m) $(USER_SINGLE_OBJS))
USER_OBJS := $(foreach file,$(USER_OBJS),$(obj)/$(file))
$(USER_OBJS:.o=.%): \
c_flags = -Wp,-MD,$(depfile) $(USER_CFLAGS) -include user.h $(CFLAGS_$(basetarget).o)
c_flags = -Wp,-MD,$(depfile) $(USER_CFLAGS) -include $(srctree)/include/linux/kern_levels.h -include user.h $(CFLAGS_$(basetarget).o)
# These are like USER_OBJS but filter USER_CFLAGS through unprofile instead of
# using it directly.

3
arch/x86/um/shared/sysdep/kernel-offsets.h
View File

@ -7,9 +7,6 @@
#define DEFINE(sym, val) \
asm volatile("\n->" #sym " %0 " #val : : "i" (val))
#define STR(x) #x
#define DEFINE_STR(sym, val) asm volatile("\n->" #sym " " STR(val) " " #val: : )
#define BLANK() asm volatile("\n->" : : )
#define OFFSET(sym, str, mem) \