The introduction of the uapi directories in v3.7-rc1 moved some of the
generated headers from arch/*/include/generated to the uapi directory,
keeping the #include directives intact.
This creates a problem when bisecting, because the unversioned files are
not cleaned automatically by git and the compiler might include stale
headers as a result. Instead of cleaning them in the Makefiles, promote
arch/*/include/generated/uapi in the search path. Under normal
circumstances, there is no overlap between this uapi subdirectory and
its parent, so the include choices remain the same. We keep
arch/*/include/generated/uapi in the USERINCLUDE variable so that it is
usable standalone.
Note that we cannot completely swap the order of the uapi and
kernel-only directories, since the headers in include/uapi/asm-generic
are meant to be wrapped by their include/asm-generic counterparts when
building kernel code.
Reported-by: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Reported-by: David Drysdale <dmd@lurklurk.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now $(version_h) is include/generated/uapi/linux/version.h.
$(version_h) in MRPROPER_FILES is redundant because it is covered
by include/generated in MRPROPER_DIRS.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
"make kvmconfig" expects that the .config has already been created,
but some people might want to create the .config and run kvmconfig
in one shot command, like this:
$ make defconfig kvmconfig
To make sure this command works correctly even if -j* option is set,
we must handle them one by one.
This commit turns on mixed-targets when $(MAKECMDGOALS) includes
at least one config target and also includes another target.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Pull kbuild updates from Michal Marek:
"Here are the kbuild changes for v3.19-rc1:
- Cleanups and deduplication in the main Makefile and
scripts/Makefile.*
- Sort the output of *config targets in make help
- Old <linux/version.h> is always removed to avoid a surprise during
bisecting
- Warning fix in kconfig"
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild: remove redundant -rR flag of hdr-inst
kbuild: Fix make help-<board series> on powerpc
kbuild: Automatically remove stale <linux/version.h> file
kconfig: Fix warning "‘jump’ may be used uninitialized"
Makefile: sort list of defconfig targets in make help output
kbuild: Remove duplicate $(cmd) definition in Makefile.clean
kbuild: collect shorthands into scripts/Kbuild.include
make ARCH=powerpc help-<board series> should not require a cofigured
source tree. Also, sort the boards in the output.
Signed-off-by: Michal Marek <mmarek@suse.cz>
In 3.7, the file moved from include/linux/ to
include/generated/uapi/linux/. The path in the #include directive
remained the same for compatibility reasons, but this created a problem
when bisecting. Commit 9c8cdb71 (kbuild: unconditionally clobber
include/linux/version.h on distclean) fixes this, provided the user does
make distclean between builds. Better not rely on the user and delete
the stale file each time make is invoked.
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Without sorting this list is completely unreadable for ARCH=arm.
Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
The shorthand "clean" is defined in both the top Makefile and
scripts/Makefile.clean. Likewise, the "hdr-inst" is defined in
both the top Makefile and scripts/Makefile.headersinst.
To reduce code duplication, this commit collects them into
scripts/Kbuild.include like the "build" and "modbuiltin" shorthands.
It requires scripts/Makefile.clean to include scripts/Kbuild.include,
but its impact on the performance of "make clean" should be
negligible.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Sasha Levin reports:
"gcc5 changes the default standard to c11, which makes kernel build
unhappy
Explicitly define the kernel standard to be gnu89 which should keep
everything working exactly like it was before gcc5"
There are multiple small issues with the new default, but the biggest
issue seems to be that the old - and very useful - GNU extension to
allow a cast in front of an initializer has gone away.
Patch updated by Kirill:
"I'm pretty sure all gcc versions you can build kernel with supports
-std=gnu89. cc-option is redunrant.
We also need to adjust HOSTCFLAGS otherwise allmodconfig fails for me"
Note by Andrew Pinski:
"Yes it was reported and both problems relating to this extension has
been added to gnu99 and gnu11. Though there are other issues with the
kernel dealing with extern inline have different semantics between
gnu89 and gnu99/11"
End result: we may be able to move up to a newer stdc model eventually,
but right now the newer models have some annoying deficiencies, so the
traditional "gnu89" model ends up being the preferred one.
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Singed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull kbuild changes from Michal Marek:
- fix for handling dependencies of *-objs targets by Masahiro Yamada
- lots of cleanups in the kbuild machinery, also by Masahiro
- fixes for the kconfig build to use an UTF-8 capable ncurses library
if possible and to build on not-so-standard installs
- some more minor fixes
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild: Do not reference *-n variables in the Makefile
kbuild: simplify build, clean, modbuiltin shorthands
kbuild: arm: Do not define "comma" twice
kbuild: remove obj-n and lib-n handling
kbuild: remove unnecessary variable initializaions
kbuild: remove unnecessary "obj- := dummy.o" trick
kbuild: handle C=... and M=... after entering into build directory
kbuild: use $(Q) for sub-make target
kbuild: fake the "Entering directory ..." message more simply
kconfig/lxdialog: get ncurses CFLAGS with pkg-config
kconfig: nconfig: fix multi-byte UTF handling
kconfig: lxdialog: fix spelling
kbuild: Make scripts executable
kbuild: remove redundant clean-files from scripts/kconfig/Makefile
kbuild: refactor script/kconfig/Makefile
kbuild: handle the dependency of multi-objs hostprogs appropriately
kbuild: handle multi-objs dependency appropriately
Pull documentation updates from Jiri Kosina:
"Updates to kernel documentation.
I took this over (hopefully temporarily) from Randy who was not
willing to maintain it any longer. This pile mostly is a relay of
queue that Randy already had in his tree"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/doc:
Documentation: fix broken v4l-utils URL
Documentation: update include path for mpssd
Documentation: correct parameter error for dma_mapping_error
MAINTAINERS: update location of linux-doc tree
Documentation: remove networking/.gitignore
tools: add more endian.h macros
Make Documenation depend on headers_install
Docs: this_cpu_ops: remove redundant add forms
Documentation: disable vdso_test to avoid breakage with old glibc
Documentation: update vDSO makefile to build portable examples
Documentation: update .gitignore files
Documentation: support glibc versions without htole macros
v4l2-pci-skeleton: Only build if PCI is available
Documentation: fix misc. warnings
Documentation: make functions static to avoid prototype warnings
Documentation: add makefiles for more targets
Documentation: use subdir-y to avoid unnecessary built-in.o files
Cheers,
Rusty.
PS. My virtio-next tree is empty: DaveM took the patches I had. There might
be a virtio-rng starvation fix, but so far it's a bit voodoo so I will
get to that in the next two days or it will wait.
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Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull module update from Rusty Russell:
"Nothing major: support for compressing modules, and auto-tainting
params.
PS. My virtio-next tree is empty: DaveM took the patches I had. There
might be a virtio-rng starvation fix, but so far it's a bit voodoo
so I will get to that in the next two days or it will wait"
* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
moduleparam: Resolve missing-field-initializer warning
kbuild: handle module compression while running 'make modules_install'.
modinst: wrap long lines in order to enhance cmd_modules_install
modsign: lookup lines ending in .ko in .mod files
modpost: simplify file name generation of *.mod.c files
modpost: reduce visibility of symbols and constify r/o arrays
param: check for tainting before calling set op.
drm/i915: taint the kernel if unsafe module parameters are set
module: add module_param_unsafe and module_param_named_unsafe
module: make it possible to have unsafe, tainting module params
module: rename KERNEL_PARAM_FL_NOARG to avoid confusion
$(if $(KBUILD_SRC),$(srctree)/) was a useful strategy
to omit a long absolute path for in-source-tree build
prior to commit 890676c65d
(kbuild: Use relative path when building in the source tree).
Now $(srctree) is "." when building in the source tree.
It would not be annoying to add "$(srctree)/" all the time.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
This commit avoids processing C=... and M=... twice
when O=... is also given.
Besides, we can also remove KBUILD_EXTMOD="$(KBUILD_EXTMOD)"
in the sub-make target.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Peter Foley <pefoley2@pefoley.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Since commit 066b7ed955
(kbuild: Do not print the build directory with make -s),
"Q" is defined above the sub-make target.
This commit takes advantage of that and replaces
"$(if $(KBUILD_VERBOSE:1=),@)" with "$(Q)".
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Peter Foley <pefoley2@pefoley.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Commit c2e28dc975
(kbuild: Print the name of the build directory)
added a gimmick to show the "Entering directory ...".
Instead of echoing the hard-coded message (that is, we need to know
the exact message), moving --no-print-directory would be easier.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Peter Foley <pefoley2@pefoley.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Since module-init-tools (gzip) and kmod (gzip and xz) support compressed
modules, it could be useful to include a support for compressing modules
right after having them installed. Doing this in kbuild instead of per
distro can permit to make this kind of usage more generic.
This patch add a Kconfig entry to "Enable loadable module support" menu
and let you choose to compress using gzip (default) or xz.
Both gzip and xz does not used any extra -[1-9] option since Andi Kleen
and Rusty Russell prove no gain is made using them. gzip is called with -n
argument to avoid storing original filename inside compressed file, that
way we can save some more bytes.
On a v3.16 kernel, 'make allmodconfig' generated 4680 modules for a
total of 378MB (no strip, no sign, no compress), the following table
shows observed disk space gain based on the allmodconfig .config :
| time |
+-------------+-----------------+
| manual .ko | make | size | percent
| compression | modules_install | | gain
+-------------+-----------------+------+--------
- | | 18.61s | 378M |
GZIP | 3m16s | 3m37s | 102M | 73.41%
XZ | 5m22s | 5m39s | 77M | 79.83%
The gain for restricted environnement seems to be interesting while
uncompress can be time consuming but happens only while loading a module,
that is generally done only once.
This is fully compatible with signed modules while the signed module is
compressed. module-init-tools or kmod handles decompression
and provide to other layer the uncompressed but signed payload.
Reviewed-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Bertrand Jacquin <beber@meleeweb.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Pull misc kbuild updates from Michal Marek:
"This is the non-critical part of kbuild for 3.17-rc1:
- make help hint to use make -s with make kernelrelease et al.
- moved a kbuild document to Documentation/kbuild where it belongs
- four new Coccinelle scripts, one dropped and one fixed
- new make kselftest target to run various tests on the kernel"
* 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild: kselftest - new make target to build and run kernel selftests
Coccinelle: Script to replace if and BUG with BUG_ON
Coccinelle: Script to detect incorrect argument to sizeof
Coccinelle: Script to use ARRAY_SIZE instead of division of two sizeofs
Coccinelle: Script to detect cast after memory allocation
coccinelle/null: solve parse error
Documentation: headers_install.txt is part of kbuild
kbuild: make -s should be used with kernelrelease/kernelversion/image_name
Pull kbuild updates from Michal Marek:
- make clean also considers $(extra-m) and $(extra-) to be consistent
- cleanup and fixes in scripts/Makefile.host
- allow to override the name of the Python 2 executable with make
PYTHON=... (only needed for ia64 in practice)
- option to split debugingo into *.dwo files to save disk space if the
compiler supports it (CONFIG_DEBUG_INFO_SPLIT)
- option to use dwarf4 debuginfo if the compiler supports it
(CONFIG_DEBUG_INFO_DWARF4)
- fix for disabling certain warnings with clang
- fix for unneeded rebuild with dash when a command contains
backslashes
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild: Fix handling of backslashes in *.cmd files
kbuild, LLVMLinux: Supress warnings unless W=1-3
Kbuild: Add a option to enable dwarf4 v2
kbuild: Support split debug info v4
kbuild: allow to override Python command name
kbuild: clean-up and bug fix of scripts/Makefile.host
kbuild: clean up scripts/Makefile.host
kbuild: drop shared library support from Makefile.host
kbuild: fix a bug of C++ host program handling
kbuild: fix a typo in scripts/Makefile.host
scripts/Makefile.clean: clean also $(extra-m) and $(extra-)
Add a new make target "kselftest" to enable kernel testing. This
new target builds and runs kernel selftests. Running as root is
recommended for a complete test run as some tests don't run when
run by non-root user. Build, install, and boot kernel before
running kselftest on it.
Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
We have been chasing a memory corruption bug, which turned out to be
caused by very old gcc (4.3.4), which happily turned conditional load
into a non-conditional one, and that broke correctness (the condition
was met only if lock was held) and corrupted memory.
This particular problem with that particular code did not happen when
never gccs were used. I've brought this up with our gcc folks, as I
wanted to make sure that this can't really happen again, and it turns
out it actually can.
Quoting Martin Jambor <mjambor@suse.cz>:
"More current GCCs are more careful when it comes to replacing a
conditional load with a non-conditional one, most notably they check
that a store happens in each iteration of _a_ loop but they assume
loops are executed. They also perform a simple check whether the
store cannot trap which currently passes only for non-const
variables. A simple testcase demonstrating it on an x86_64 is for
example the following:
$ cat cond_store.c
int g_1 = 1;
int g_2[1024] __attribute__((section ("safe_section"), aligned (4096)));
int c = 4;
int __attribute__ ((noinline))
foo (void)
{
int l;
for (l = 0; (l != 4); l++) {
if (g_1)
return l;
for (g_2[0] = 0; (g_2[0] >= 26); ++g_2[0])
;
}
return 2;
}
int main (int argc, char* argv[])
{
if (mprotect (g_2, sizeof(g_2), PROT_READ) == -1)
{
int e = errno;
error (e, e, "mprotect error %i", e);
}
foo ();
__builtin_printf("OK\n");
return 0;
}
/* EOF */
$ ~/gcc/trunk/inst/bin/gcc cond_store.c -O2 --param allow-store-data-races=0
$ ./a.out
OK
$ ~/gcc/trunk/inst/bin/gcc cond_store.c -O2 --param allow-store-data-races=1
$ ./a.out
Segmentation fault
The testcase fails the same at least with 4.9, 4.8 and 4.7. Therefore
I would suggest building kernels with this parameter set to zero. I
also agree with Jikos that the default should be changed for -O2. I
have run most of the SPEC 2k6 CPU benchmarks (gamess and dealII
failed, at -O2, not sure why) compiled with and without this option
and did not see any real difference between respective run-times"
Hopefully the default will be changed in newer gccs, but let's force it
for kernel builds so that we are on a safe side even when older gcc are
used.
The code in question was out-of-tree printk-in-NMI (yeah, surprise
suprise, once again) patch written by Petr Mladek, let me quote his
comment from our internal bugzilla:
"I have spent few days investigating inconsistent state of kernel ring buffer.
It went out that it was caused by speculative store generated by
gcc-4.3.4.
The problem is in assembly generated for make_free_space(). The functions is
called the following way:
+ vprintk_emit();
+ log = MAIN_LOG; // with logbuf_lock
or
log = NMI_LOG; // with nmi_logbuf_lock
cont_add(log, ...);
+ cont_flush(log, ...);
+ log_store(log, ...);
+ log_make_free_space(log, ...);
If called with log = NMI_LOG then only nmi_log_* global variables are safe to
modify but the generated code does store also into (main_)log_* global
variables:
<log_make_free_space>:
55 push %rbp
89 f6 mov %esi,%esi
48 8b 05 03 99 51 01 mov 0x1519903(%rip),%rax # ffffffff82620868 <nmi_log_next_id>
44 8b 1d ec 98 51 01 mov 0x15198ec(%rip),%r11d # ffffffff82620858 <log_next_idx>
8b 35 36 60 14 01 mov 0x1146036(%rip),%esi # ffffffff8224cfa8 <log_buf_len>
44 8b 35 33 60 14 01 mov 0x1146033(%rip),%r14d # ffffffff8224cfac <nmi_log_buf_len>
4c 8b 2d d0 98 51 01 mov 0x15198d0(%rip),%r13 # ffffffff82620850 <log_next_seq>
4c 8b 25 11 61 14 01 mov 0x1146111(%rip),%r12 # ffffffff8224d098 <log_buf>
49 89 c2 mov %rax,%r10
48 21 c2 and %rax,%rdx
48 8b 1d 0c 99 55 01 mov 0x155990c(%rip),%rbx # ffffffff826608a0 <nmi_log_buf>
49 c1 ea 20 shr $0x20,%r10
48 89 55 d0 mov %rdx,-0x30(%rbp)
44 29 de sub %r11d,%esi
45 29 d6 sub %r10d,%r14d
4c 8b 0d 97 98 51 01 mov 0x1519897(%rip),%r9 # ffffffff82620840 <log_first_seq>
eb 7e jmp ffffffff81107029 <log_make_free_space+0xe9>
[...]
85 ff test %edi,%edi # edi = 1 for NMI_LOG
4c 89 e8 mov %r13,%rax
4c 89 ca mov %r9,%rdx
74 0a je ffffffff8110703d <log_make_free_space+0xfd>
8b 15 27 98 51 01 mov 0x1519827(%rip),%edx # ffffffff82620860 <nmi_log_first_id>
48 8b 45 d0 mov -0x30(%rbp),%rax
48 39 c2 cmp %rax,%rdx # end of loop
0f 84 da 00 00 00 je ffffffff81107120 <log_make_free_space+0x1e0>
[...]
85 ff test %edi,%edi # edi = 1 for NMI_LOG
4c 89 0d 17 97 51 01 mov %r9,0x1519717(%rip) # ffffffff82620840 <log_first_seq>
^^^^^^^^^^^^^^^^^^^^^^^^^^
KABOOOM
74 35 je ffffffff81107160 <log_make_free_space+0x220>
It stores log_first_seq when edi == NMI_LOG. This instructions are used also
when edi == MAIN_LOG but the store is done speculatively before the condition
is decided. It is unsafe because we do not have "logbuf_lock" in NMI context
and some other process migh modify "log_first_seq" in parallel"
I believe that the best course of action is both
- building kernel (and anything multi-threaded, I guess) with that
optimization turned off
- persuade gcc folks to change the default for future releases
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Martin Jambor <mjambor@suse.cz>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Marek Polacek <polacek@redhat.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Steven Noonan <steven@uplinklabs.net>
Cc: Richard Biener <richard.guenther@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds a hopefully helpful comment above the (seemingly weird) compiler
flag selection logic.
Signed-off-by: Kees Cook <keescook@chromium.org>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
clang has more warnings enabled by default. Turn them off unless W is
set. This patch fixes a logic bug where warnings in clang were disabled
when W was set.
Signed-off-by: Behan Webster <behanw@converseincode.com>
Signed-off-by: Jan-Simon Möller <dl9pf@gmx.de>
Signed-off-by: Mark Charlebois <charlebm@gmail.com>
Cc: bp@alien8.de
Signed-off-by: Michal Marek <mmarek@suse.cz>
I found that a lot of unresolvable variables when using gdb on the
kernel become resolvable when dwarf4 is enabled. So add a Kconfig flag
to enable it.
It definitely increases the debug information size, but on the other
hand this isn't so bad when debug fusion is used.
v2: Use cc-option
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
This is an alternative approach to lower the overhead of debug info
(as we discussed a few days ago)
gcc 4.7+ and newer binutils have a new "split debug info" debug info
model where the debug info is only written once into central ".dwo" files.
This avoids having to copy it around multiple times, from the object
files to the final executable. It lowers the disk space
requirements. In addition it defaults to compressed debug data.
More details here: http://gcc.gnu.org/wiki/DebugFission
This patch adds a new option to enable it. It has to be an option,
because it'll undoubtedly break everyone's debuginfo packaging scheme.
gdb/objdump/etc. all still work, if you have new enough versions.
I don't see big compile wins (maybe a second or two faster or so), but the
object dirs with debuginfo get significantly smaller. My standard kernel
config (slightly bigger than defconfig) shrinks from 2.9G disk space
to 1.1G objdir (with non reduced debuginfo). I presume if you are IO limited
the compile time difference will be larger.
Only problem I've seen so far is that it doesn't play well with older
versions of ccache (apparently fixed, see
https://bugzilla.samba.org/show_bug.cgi?id=10005)
v2: various fixes from Dirk Gouders. Improve commit message slightly.
v3: Fix clean rules and improve Kconfig slightly
v4: Fix merge error in last version (Sam Ravnborg)
Clarify description that it mainly helps disk size.
Cc: Dirk Gouders <dirk@gouders.net>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Michel Dänzer and a couple of other people reported inexplicable random
oopses in the scheduler, and the cause turns out to be gcc mis-compiling
the load_balance() function when debugging is enabled. The gcc bug
apparently goes back to gcc-4.5, but slight optimization changes means
that it now showed up as a problem in 4.9.0 and 4.9.1.
The instruction scheduling problem causes gcc to schedule a spill
operation to before the stack frame has been created, which in turn can
corrupt the spilled value if an interrupt comes in. There may be other
effects of this bug too, but that's the code generation problem seen in
Michel's case.
This is fixed in current gcc HEAD, but the workaround as suggested by
Markus Trippelsdorf is pretty simple: use -fno-var-tracking-assignments
when compiling the kernel, which disables the gcc code that causes the
problem. This can result in slightly worse debug information for
variable accesses, but that is infinitely preferable to actual code
generation problems.
Doing this unconditionally (not just for CONFIG_DEBUG_INFO) also allows
non-debug builds to verify that the debug build would be identical: we
can do
export GCC_COMPARE_DEBUG=1
to make gcc internally verify that the result of the build is
independent of the "-g" flag (it will make the compiler build everything
twice, toggling the debug flag, and compare the results).
Without the "-fno-var-tracking-assignments" option, the build would fail
(even with 4.8.3 that didn't show the actual stack frame bug) with a gcc
compare failure.
See also gcc bugzilla:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61801
Reported-by: Michel Dänzer <michel@daenzer.net>
Suggested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The specification of Python 3 is largely different from that of
Python 2.
For example, arch/ia64/scripts/unwcheck.py seems to be written
in Python 2, not compatible with Python 3.
It is not a good idea to invoke python scripts with the hard-coded
command name 'python'. The command 'python' could possibly be
Python 3 on some systems.
For that case, it is reasonable to allow to override the command name
by giving 'PYTHON=python2' from the command line.
The 'python' in arch/ia64/Makefile should be replaced with '$(PYTHON)'.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: linux-ia64@vger.kernel.org
Signed-off-by: Michal Marek <mmarek@suse.cz>
If .config has been edited, there will be a silentoldconfig run:
$ make defconfig
...
$ make kernelrelease
scripts/kconfig/conf --silentoldconfig Kconfig
3.16.0-rc1+
Recently, kbuild started to print the name of the build directory when
using O=
$ make O=build kernelrelease
make[1]: Entering directory `/dev/shm/mmarek/linux-2.6/build'
3.16.0-rc1+
Since these targets are often used in scripts, add a hint to use make -s
to the help text.
Suggested-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Pull kbuild fixes from Michal Marek:
"Three more fixes for the relative build dir feature:
- Shut up make -s again
- Fix for rpm/deb/tar-pkg with O=<subdir>
- Fix for CONFIG_EXTRA_FIRMWARE"
* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
firmware: Create directories for external firmware
kbuild: Fix packaging targets with relative $(srctree)
kbuild: Do not print the build directory with make -s
All other users of Makefile.build set $(obj) to the name of the
subdirectory to build. Do the same for the packaging targets, otherwise
the build fails if $(srctree) is a relative directory:
$ make O=build tar-pkg
make[1]: Entering directory `/home/mmarek/linux-2.6/build'
CHK include/config/kernel.release
../scripts/Makefile.build:44: ../../scripts/package/Makefile: No such file or directory
make[2]: *** No rule to make target `../../scripts/package/Makefile'. Stop.
Fixes: 9da0763b ("kbuild: Use relative path when building in a subdir of the source tree")
Signed-off-by: Michal Marek <mmarek@suse.cz>
Commit c2e28dc9 (kbuild: Print the name of the build directory) prints
the name of the build directory for O= builds, but we should not be
doing this in make -s mode, so that commands like
make -s O=<dir> kernelrelease
can be used by scripts. This matches the behavior of make itself, where
the -s option implies --no-print-directory.
Signed-off-by: Michal Marek <mmarek@suse.cz>
Pull kbuild fix from Michal Marek:
"There is one more fix for the relative paths series from -rc1: Print
the path to the build directory at the start of the build, so that
editors and IDEs can match the relative paths to source files"
* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild: Print the name of the build directory
With commit 9da0763b (kbuild: Use relative path when building in a
subdir of the source tree), the compiler messages include relative
paths. These are however relative to the build directory, not the
directory where make was started. Print the "Entering directory ..."
message once, so that IDEs/editors can find the source files.
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Pull kbuild updates from Michal Marek:
"Kbuild changes for v3.16-rc1:
- cross-compilation fix so that cc-option is testing the right
compiler
- Fix for make defconfig all
- Using relative paths to the object and source directory where
possible, plus fixes for the fallout of the change
- several cleanups in the Makefiles and scripts
The powerpc fix is from today, because it was only discovered
recently. The rest has been in linux-next for some time"
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
powerpc: Avoid circular dependency with zImage.%
kbuild: create include/config directory in scripts/kconfig/Makefile
kbuild: do not create include/linux directory
Makefile: Fix unrecognized cross-compiler command line options
kbuild: do not add "selinux" to subdir- twice
um: Fix for relative objtree when generating x86 headers
kbuild: Use relative path when building in a subdir of the source tree
kbuild: Use relative path when building in the source tree
kbuild: Use relative path for $(objtree)
firmware: Use $(quote) in the Makefile
firmware: Simplify directory creation
kbuild: trivial - fix comment block indent
kbuild: trivial - remove trailing spaces
kbuild: support simultaneous "make %config" and "make all"
kbuild: move extra gcc checks to scripts/Makefile.extrawarn
The directory include/config is used only for
silentoldconfig, localmodconfig, localyesconfig.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
There are no generated files under include/linux directory.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
On architectures that setup CROSS_COMPILE in their arch/*/Makefile
(arc, blackfin, m68k, mips, parisc, score, sh, tile, unicore32, xtensa),
cc-option and cc-disable-warning may check against the wrong compiler,
causing errors like
cc1: error: unrecognized command line option "-Wno-maybe-uninitialized"
if the host gcc supports a compiler option, while the cross compiler
doesn't support that option.
Move all logic using cc-option or cc-disable-warning below the inclusion
of the arch's Makefile to fix this.
Introduced by
- commit e74fc973b6 ("Turn off
-Wmaybe-uninitialized when building with -Os"),
- commit 61163efae0 ("kbuild: LLVMLinux:
Add Kbuild support for building kernel with Clang").
As -Wno-maybe-uninitialized requires a quite recent gcc (gcc 4.6.3 on
Ubuntu 12.04 LTS doesn't support it), this only showed up recently (gcc
4.8.2 on Ubuntu 14.04 LTS does support it).
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
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Merge tag 'llvmlinux-for-v3.16' of git://git.linuxfoundation.org/llvmlinux/kernel
Pull LLVM patches from Behan Webster:
"Next set of patches to support compiling the kernel with clang.
They've been soaking in linux-next since the last merge window.
More still in the works for the next merge window..."
* tag 'llvmlinux-for-v3.16' of git://git.linuxfoundation.org/llvmlinux/kernel:
arm, unwind, LLVMLinux: Enable clang to be used for unwinding the stack
ARM: LLVMLinux: Change "extern inline" to "static inline" in glue-cache.h
all: LLVMLinux: Change DWARF flag to support gcc and clang
net: netfilter: LLVMLinux: vlais-netfilter
crypto: LLVMLinux: aligned-attribute.patch
Both gcc (well, actually gnu as) and clang support the "-Wa,-gdwarf-2" option
(though clang does not support "-Wa,--gdwarf-2"). Since these flags are equivalent
in meaning, this patch uses the one which is better supported across compilers.
Signed-off-by: Behan Webster <behanw@converseincode.com>
When doing make O=<subdir>, use '..' to refer to the source tree. This
allows for more readable compiler messages, and, more importantly, it
sets the VPATH to '..', so filenames in WARN_ON() etc. will be shorter.
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
When not using O=, $(srctree) refers to the same directory as
$(objtree), so we can set it to '.' as well. This makes the default
include path more compact and results in more readable messages from the
compiler. The only case where we need the absolute path is when creating
the 'source' symlink in /lib/modules.
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
The main Makefile sets its working directory to the object tree and
never changes it again. Therefore, we can use '.' instead of the
absolute path. The only case where we need the absolute path is when
creating the 'build' symlink in /lib/modules.
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Kbuild is supposed to support mixed targets. (%config and build targets)
But "make all" did nothing if it was run with configuration targets.
For example,
$ LANG=C make defconfig all
HOSTCC scripts/basic/fixdep
HOSTCC scripts/kconfig/conf.o
SHIPPED scripts/kconfig/zconf.tab.c
SHIPPED scripts/kconfig/zconf.lex.c
SHIPPED scripts/kconfig/zconf.hash.c
HOSTCC scripts/kconfig/zconf.tab.o
HOSTLD scripts/kconfig/conf
*** Default configuration is based on 'x86_64_defconfig'
#
# configuration written to .config
#
make: Nothing to be done for `all'.
This commits allows "make %config all" and makes sure
mixed targets are built one by one in the given order.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Michal Marek <mmarek@suse.cz>
CC: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
W=... provides extra gcc checks.
Having such code in scripts/Makefile.build results in the same flags
being added to KBUILD_CFLAGS multiple times becuase
scripts/Makefile.build is invoked every time Kbuild descends into
the subdirectories.
Since the top Makefile is already too cluttered, this commit moves
all of extra gcc check stuff to a new file scripts/Makefile.extrawarn,
which is included from the top Makefile.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
CC: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Pull misc kbuild changes from Michal Marek:
"Here is the non-critical part of kbuild:
- One bogus coccinelle check removed, one check fixed not to suggest
the obsolete PTR_RET macro
- scripts/tags.sh does not index the generated *.mod.c files
- new objdiff tool to list differences between two versions of an
object file
- A fix for scripts/bootgraph.pl"
* 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
scripts/coccinelle: Use PTR_ERR_OR_ZERO
scripts/bootgraph.pl: Add graphic header
scripts: objdiff: detect object code changes between two commits
Coccicheck: Remove memcpy to struct assignment test
scripts/tags.sh: Ignore *.mod.c
Add support to toplevel Makefile for compiling with clang, both for
HOSTCC and CC. Use cc-option to prevent gcc option from breaking clang, and
from clang options from breaking gcc.
Clang 3.4 semantics are the same as gcc semantics for unsupported flags. For
unsupported warnings clang 3.4 returns true but shows a warning and gcc shows
a warning and returns false.
Signed-off-by: Behan Webster <behanw@converseincode.com>
Signed-off-by: Jan-Simon Möller <dl9pf@gmx.de>
Signed-off-by: Mark Charlebois <charlebm@gmail.com>
Cc: PaX Team <pageexec@freemail.hu>
objdiff is useful when doing large code cleanups. For example, when
removing checkpatch warnings and errors from new drivers in the staging
tree.
objdiff can be used in conjunction with a git rebase to confirm that
each commit made no changes to the resulting object code. It has the
same return values as diff(1).
This was written specifically to support adding the skein and threefish
cryto drivers to the staging tree. I needed a programmatic way to
confirm that commits changing >90% of the lines didn't inadvertently
change the code.
Temporary files (objdump output) are stored in
/path/to/linux/.tmp_objdiff
'make mrproper' will remove this directory.
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Pull kbuild changes from Michal Marek:
- cleanups in the main Makefiles and Documentation/DocBook/Makefile
- make O=... directory is automatically created if needed
- mrproper/distclean removes the old include/linux/version.h to make
life easier when bisecting across the commit that moved the version.h
file
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild: docbook: fix the include error when executing "make help"
kbuild: create a build directory automatically for out-of-tree build
kbuild: remove redundant '.*.cmd' pattern from make distclean
kbuild: move "quote" to Kbuild.include to be consistent
kbuild: docbook: use $(obj) and $(src) rather than specific path
kbuild: unconditionally clobber include/linux/version.h on distclean
kbuild: docbook: specify KERNELDOC dependency correctly
kbuild: docbook: include cmd files more simply
kbuild: specify build_docproc as a phony target
Updates to devicetree core code. This branch contains the following notable changes:
* Add reserved memory binding
* Make struct device_node a kobject and remove legacy /proc/device-tree
* ePAPR conformance fixes
* Update in-kernel DTC copy to version v1.4.0
* Preparation changes for dynamic device tree overlays
* minor bug fixes and documentation changes
The most significant change in this branch is the conversion of struct
device_node to be a kobject that is exposed via sysfs and removal of the
old /proc/device-tree code. This simplifies the device tree handling
code and tightens up the lifecycle on device tree nodes.
[updated: added fix for dangling select PROC_DEVICETREE]
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Merge tag 'dt-for-linus' of git://git.secretlab.ca/git/linux
Pull devicetree changes from Grant Likely:
"Updates to devicetree core code. This branch contains the following
notable changes:
- add reserved memory binding
- make struct device_node a kobject and remove legacy
/proc/device-tree
- ePAPR conformance fixes
- update in-kernel DTC copy to version v1.4.0
- preparatory changes for dynamic device tree overlays
- minor bug fixes and documentation changes
The most significant change in this branch is the conversion of struct
device_node to be a kobject that is exposed via sysfs and removal of
the old /proc/device-tree code. This simplifies the device tree
handling code and tightens up the lifecycle on device tree nodes.
[updated: added fix for dangling select PROC_DEVICETREE]"
* tag 'dt-for-linus' of git://git.secretlab.ca/git/linux: (29 commits)
dt: Remove dangling "select PROC_DEVICETREE"
of: Add support for ePAPR "stdout-path" property
of: device_node kobject lifecycle fixes
of: only scan for reserved mem when fdt present
powerpc: add support for reserved memory defined by device tree
arm64: add support for reserved memory defined by device tree
of: add missing major vendors
of: add vendor prefix for SMSC
of: remove /proc/device-tree
of/selftest: Add self tests for manipulation of properties
of: Make device nodes kobjects so they show up in sysfs
arm: add support for reserved memory defined by device tree
drivers: of: add support for custom reserved memory drivers
drivers: of: add initialization code for dynamic reserved memory
drivers: of: add initialization code for static reserved memory
of: document bindings for reserved-memory nodes
Revert "of: fix of_update_property()"
kbuild: dtbs_install: new make target
ARM: mvebu: Allows to get the SoC ID even without PCI enabled
of: Allows to use the PCI translator without the PCI core
...
Kbuild supports saving output files in a separate directory.
But the build directory must be created beforehand. For example,
$ mkdir -p dir/to/store/output/files
$ make O=dir/to/store/output/files defconfig
Creating a build directory automatically would be useful.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
'.*.cmd' files are cleaned-up by "make clean".
The same pattern in "make distclean" is unnecessary.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
As of v3.7, the UAPI changes relocated headers around such that the
kernel version header lived in a new place.
If a person is bisecting and if you go back to pre-UAPI days,
you will create an include/linux/version.h -- then if you checkout a
post-UAPI kernel, and even run "make distclean" it still won't delete
that old version file. So you get a situation like this:
$ grep -R LINUX_VERSION_CODE include/
include/generated/uapi/linux/version.h:#define LINUX_VERSION_CODE 200192
include/linux/version.h:#define LINUX_VERSION_CODE 132646
The value in that second line is representative of a v2.6.38 version.
And it will be sourced/used, hence leading to strange behaviours, such
as drivers/staging content (which typically hasn't been purged of version
ifdefs) failing to build.
Since it is a subtle mode of failure, lets always clobber the old
file when doing a distclean.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
According to Documentation/Changes, make 3.80 is still being supported
for building the kernel, hence make files must not make (unconditional)
use of features introduced only in newer versions. Commit 8779657d29
("stackprotector: Introduce CONFIG_CC_STACKPROTECTOR_STRONG") however
introduced an "else ifdef" construct which make 3.80 doesn't understand.
Also correct a warning message still referencing the old config option
name.
Apart from that I question the use of "ifdef" here (but it was used that
way already prior to said commit): ifeq (,y) would seem more to the
point.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Michal Marek
Masahiro Yamada
Linus Torvalds
Konstantin Khlebnikov
Kirill A. Shutemov
Peter Foley
Bertrand Jacquin
Shuah Khan
Jiri Kosina
Kees Cook
Behan Webster
Andi Kleen
Geert Uytterhoeven
Jason Cooper
Grant Likely
Paul Gortmaker
Jan Beulich