Re: [PATCH v8 00/21] Compile-time stack validation

Re: [PATCH v8 00/21] Compile-time stack validation

[Chris J Arges]

Josh,

I've applied and tried to build your patchset against the latest
mainline kernel with the following config:
http://paste.ubuntu.com/12058017/

I can build if I disable CONFIG_STACK_VALIDATION, then re-enable it
after all objects are already built, so this seems like it should be
resolvable in Makefiles. Any suggestions for debugging this?

Building from clean I get the following:
~/linux$ make
  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/basic/bin2c
  GEN     arch/x86/lib/inat-tables.c
  HOSTCC  arch/x86/tools/relocs_32.o
  HOSTCC  arch/x86/tools/relocs_64.o
  HOSTCC  arch/x86/tools/relocs_common.o
  HOSTLD  arch/x86/tools/relocs
  CHK     include/config/kernel.release
  CHK     include/generated/uapi/linux/version.h
  CHK     include/generated/utsrelease.h
  CC      arch/x86/purgatory/purgatory.o
  AS      arch/x86/purgatory/stack.o
  AS      arch/x86/purgatory/setup-x86_64.o
  CC      arch/x86/purgatory/sha256.o
  AS      arch/x86/purgatory/entry64.o
  CC      arch/x86/purgatory/string.o
  LD      arch/x86/purgatory/purgatory.ro
  BIN2C   arch/x86/purgatory/kexec-purgatory.c
  CC      kernel/bounds.s
  CHK     include/generated/bounds.h
  CHK     include/generated/timeconst.h
  CC      arch/x86/kernel/asm-offsets.s
  CHK     include/generated/asm-offsets.h
  CALL    scripts/checksyscalls.sh
  HOSTCC  scripts/genksyms/genksyms.o
  HOSTCC  scripts/genksyms/parse.tab.o
  HOSTCC  scripts/genksyms/lex.lex.o
  HOSTLD  scripts/genksyms/genksyms
  CC      scripts/mod/empty.o
scripts/mod/empty.o
open: No such file or directory
error reading elf file scripts/mod/empty.o
scripts/Makefile.build:284: recipe for target 'scripts/mod/empty.o' failed
make[2]: *** [scripts/mod/empty.o] Error 1
scripts/Makefile.build:429: recipe for target 'scripts/mod' failed
make[1]: *** [scripts/mod] Error 2
Makefile:545: recipe for target 'scripts' failed
make: *** [scripts] Error 2

Re: [PATCH v8 00/21] Compile-time stack validation

[Josh Poimboeuf]

On Tue, Aug 11, 2015 at 04:31:07PM -0500, Chris J Arges wrote:
> Josh,
> 
> I've applied and tried to build your patchset against the latest
> mainline kernel with the following config:
> http://paste.ubuntu.com/12058017/
> 
> I can build if I disable CONFIG_STACK_VALIDATION, then re-enable it
> after all objects are already built, so this seems like it should be
> resolvable in Makefiles. Any suggestions for debugging this?
> 
> Building from clean I get the following:
> ~/linux$ make
>   HOSTCC  scripts/basic/fixdep
>   HOSTCC  scripts/basic/bin2c
>   GEN     arch/x86/lib/inat-tables.c
>   HOSTCC  arch/x86/tools/relocs_32.o
>   HOSTCC  arch/x86/tools/relocs_64.o
>   HOSTCC  arch/x86/tools/relocs_common.o
>   HOSTLD  arch/x86/tools/relocs
>   CHK     include/config/kernel.release
>   CHK     include/generated/uapi/linux/version.h
>   CHK     include/generated/utsrelease.h
>   CC      arch/x86/purgatory/purgatory.o
>   AS      arch/x86/purgatory/stack.o
>   AS      arch/x86/purgatory/setup-x86_64.o
>   CC      arch/x86/purgatory/sha256.o
>   AS      arch/x86/purgatory/entry64.o
>   CC      arch/x86/purgatory/string.o
>   LD      arch/x86/purgatory/purgatory.ro
>   BIN2C   arch/x86/purgatory/kexec-purgatory.c
>   CC      kernel/bounds.s
>   CHK     include/generated/bounds.h
>   CHK     include/generated/timeconst.h
>   CC      arch/x86/kernel/asm-offsets.s
>   CHK     include/generated/asm-offsets.h
>   CALL    scripts/checksyscalls.sh
>   HOSTCC  scripts/genksyms/genksyms.o
>   HOSTCC  scripts/genksyms/parse.tab.o
>   HOSTCC  scripts/genksyms/lex.lex.o
>   HOSTLD  scripts/genksyms/genksyms
>   CC      scripts/mod/empty.o
> scripts/mod/empty.o
> open: No such file or directory
> error reading elf file scripts/mod/empty.o
> scripts/Makefile.build:284: recipe for target 'scripts/mod/empty.o' failed
> make[2]: *** [scripts/mod/empty.o] Error 1
> scripts/Makefile.build:429: recipe for target 'scripts/mod' failed
> make[1]: *** [scripts/mod] Error 2
> Makefile:545: recipe for target 'scripts' failed
> make: *** [scripts] Error 2

Thanks for trying it out.  I couldn't figure out how to recreate this
exact error, but I played around with "make mrproper" and saw some
probably related errors.  Does this fix it?

---8<---

Subject: [PATCH] stackvalidate: fix circular build dependencies

After "make mrproper" with CONFIG_STACK_VALIDATION enabled, I get the
following errors:

  make[2]: *** No rule to make target 'arch/x86/purgatory/purgatory.o', needed by 'arch/x86/purgatory/purgatory.ro'.  Stop.
  make[3]: *** No rule to make target 'scripts/mod/empty.o', needed by 'scripts/mod/elfconfig.h'.  Stop.

These are caused by circular dependencies.  The %.o pattern rules in
scripts/Makefile.build have the stackvalidate binary listed as a
dependency.  But stackvalidate gets built *after* archprepare and
scripts/mod, both of which build objects using the %.o pattern rules.

The STACKVALIDATE and STACKVALIDATE_foo.o variables are already used to
determine whether to validate a given object.  Also use them to
determine whether to create the pattern rule dependency.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
 scripts/Makefile.build | 7 +++++--
 scripts/mod/Makefile   | 2 ++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index a1270d3..ec96c51 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -243,7 +243,7 @@ endif
 
 ifdef CONFIG_STACK_VALIDATION
 
-stackvalidate = $(objtree)/scripts/stackvalidate/stackvalidate
+__stackvalidate = $(objtree)/scripts/stackvalidate/stackvalidate
 
 ifndef CONFIG_FRAME_POINTER
 nofp = --no-frame-pointer
@@ -251,9 +251,12 @@ endif
 
 # Set STACKVALIDATE_foo.o=n to skip stack validation for a file.
 # Set STACKVALIDATE=n to skip stack validation for a directory.
+stackvalidate = $(if $(patsubst n%,, \
+	$(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \
+	$(__stackvalidate))
 cmd_stackvalidate = $(if $(patsubst n%,, \
 	$(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \
-	$(stackvalidate) $(nofp) "$(@)";)
+	$(__stackvalidate) $(nofp) "$(@)";)
 
 endif # CONFIG_STACK_VALIDATION
 
diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile
index c11212f..374c413 100644
--- a/scripts/mod/Makefile
+++ b/scripts/mod/Makefile
@@ -1,3 +1,5 @@
+STACKVALIDATE	:= n
+
 hostprogs-y	:= modpost mk_elfconfig
 always		:= $(hostprogs-y) empty.o
 
-- 
2.4.3

Re: [PATCH v8 00/21] Compile-time stack validation

[Chris J Arges]

<snip>
> 
> Thanks for trying it out.  I couldn't figure out how to recreate this
> exact error, but I played around with "make mrproper" and saw some
> probably related errors.  Does this fix it?
> 
> ---8<---
> 
> Subject: [PATCH] stackvalidate: fix circular build dependencies
> 
> After "make mrproper" with CONFIG_STACK_VALIDATION enabled, I get the
> following errors:
> 
>   make[2]: *** No rule to make target 'arch/x86/purgatory/purgatory.o', needed by 'arch/x86/purgatory/purgatory.ro'.  Stop.
>   make[3]: *** No rule to make target 'scripts/mod/empty.o', needed by 'scripts/mod/elfconfig.h'.  Stop.
> 
> These are caused by circular dependencies.  The %.o pattern rules in
> scripts/Makefile.build have the stackvalidate binary listed as a
> dependency.  But stackvalidate gets built *after* archprepare and
> scripts/mod, both of which build objects using the %.o pattern rules.
> 
> The STACKVALIDATE and STACKVALIDATE_foo.o variables are already used to
> determine whether to validate a given object.  Also use them to
> determine whether to create the pattern rule dependency.
> 
> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
> ---
>  scripts/Makefile.build | 7 +++++--
>  scripts/mod/Makefile   | 2 ++
>  2 files changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> index a1270d3..ec96c51 100644
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -243,7 +243,7 @@ endif
>  
>  ifdef CONFIG_STACK_VALIDATION
>  
> -stackvalidate = $(objtree)/scripts/stackvalidate/stackvalidate
> +__stackvalidate = $(objtree)/scripts/stackvalidate/stackvalidate
>  
>  ifndef CONFIG_FRAME_POINTER
>  nofp = --no-frame-pointer
> @@ -251,9 +251,12 @@ endif
>  
>  # Set STACKVALIDATE_foo.o=n to skip stack validation for a file.
>  # Set STACKVALIDATE=n to skip stack validation for a directory.
> +stackvalidate = $(if $(patsubst n%,, \
> +	$(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \
> +	$(__stackvalidate))
>  cmd_stackvalidate = $(if $(patsubst n%,, \
>  	$(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \
> -	$(stackvalidate) $(nofp) "$(@)";)
> +	$(__stackvalidate) $(nofp) "$(@)";)
>  
>  endif # CONFIG_STACK_VALIDATION
>  
> diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile
> index c11212f..374c413 100644
> --- a/scripts/mod/Makefile
> +++ b/scripts/mod/Makefile
> @@ -1,3 +1,5 @@
> +STACKVALIDATE	:= n
> +
>  hostprogs-y	:= modpost mk_elfconfig
>  always		:= $(hostprogs-y) empty.o
>  
> 

Josh,

I still get build failures and I've pared it down to x86_64 defconfig plus:
CONFIG_MODVERSIONS=y
CONFIG_STACK_VALIDATION=y

And it seems like some modules may get the .tmp_foo.o treatment while
others end up foo.o so something like the following will not work:

cmd_stackvalidate = $(if $(patsubst n%,, \
        $(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \
        $(__stackvalidate) $(nofp) "$(@D)/.tmp_$(@F)";)

In addition, I'm not sure if skipping modules like STACKVALIDATE_foo.o=n
will still function properly for modversioned modules.

I'll try to look at this more tomorrow,
--chris j arges

Re: [PATCH v8 00/21] Compile-time stack validation

[Josh Poimboeuf]

On Wed, Aug 12, 2015 at 04:24:49PM -0500, Chris J Arges wrote:
> <snip>
> > 
> > Thanks for trying it out.  I couldn't figure out how to recreate this
> > exact error, but I played around with "make mrproper" and saw some
> > probably related errors.  Does this fix it?
> > 
> > ---8<---
> > 
> > Subject: [PATCH] stackvalidate: fix circular build dependencies
> > 
> > After "make mrproper" with CONFIG_STACK_VALIDATION enabled, I get the
> > following errors:
> > 
> >   make[2]: *** No rule to make target 'arch/x86/purgatory/purgatory.o', needed by 'arch/x86/purgatory/purgatory.ro'.  Stop.
> >   make[3]: *** No rule to make target 'scripts/mod/empty.o', needed by 'scripts/mod/elfconfig.h'.  Stop.
> > 
> > These are caused by circular dependencies.  The %.o pattern rules in
> > scripts/Makefile.build have the stackvalidate binary listed as a
> > dependency.  But stackvalidate gets built *after* archprepare and
> > scripts/mod, both of which build objects using the %.o pattern rules.
> > 
> > The STACKVALIDATE and STACKVALIDATE_foo.o variables are already used to
> > determine whether to validate a given object.  Also use them to
> > determine whether to create the pattern rule dependency.
> > 
> > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
> > ---
> >  scripts/Makefile.build | 7 +++++--
> >  scripts/mod/Makefile   | 2 ++
> >  2 files changed, 7 insertions(+), 2 deletions(-)
> > 
> > diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> > index a1270d3..ec96c51 100644
> > --- a/scripts/Makefile.build
> > +++ b/scripts/Makefile.build
> > @@ -243,7 +243,7 @@ endif
> >  
> >  ifdef CONFIG_STACK_VALIDATION
> >  
> > -stackvalidate = $(objtree)/scripts/stackvalidate/stackvalidate
> > +__stackvalidate = $(objtree)/scripts/stackvalidate/stackvalidate
> >  
> >  ifndef CONFIG_FRAME_POINTER
> >  nofp = --no-frame-pointer
> > @@ -251,9 +251,12 @@ endif
> >  
> >  # Set STACKVALIDATE_foo.o=n to skip stack validation for a file.
> >  # Set STACKVALIDATE=n to skip stack validation for a directory.
> > +stackvalidate = $(if $(patsubst n%,, \
> > +	$(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \
> > +	$(__stackvalidate))
> >  cmd_stackvalidate = $(if $(patsubst n%,, \
> >  	$(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \
> > -	$(stackvalidate) $(nofp) "$(@)";)
> > +	$(__stackvalidate) $(nofp) "$(@)";)
> >  
> >  endif # CONFIG_STACK_VALIDATION
> >  
> > diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile
> > index c11212f..374c413 100644
> > --- a/scripts/mod/Makefile
> > +++ b/scripts/mod/Makefile
> > @@ -1,3 +1,5 @@
> > +STACKVALIDATE	:= n
> > +
> >  hostprogs-y	:= modpost mk_elfconfig
> >  always		:= $(hostprogs-y) empty.o
> >  
> > 
> 
> Josh,
> 
> I still get build failures and I've pared it down to x86_64 defconfig plus:
> CONFIG_MODVERSIONS=y
> CONFIG_STACK_VALIDATION=y

Are you still seeing the same error as before?  I think the errors you
saw were caused by stackvalidate choking on scripts/mod/empty.o.  But I
don't see how that's still possible with the above patch since I set
STACKVALIDATE to 'n' in scripts/mod/Makefile which should tell it to
skip the directory.

> And it seems like some modules may get the .tmp_foo.o treatment while
> others end up foo.o so something like the following will not work:
> 
> cmd_stackvalidate = $(if $(patsubst n%,, \
>         $(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \
>         $(__stackvalidate) $(nofp) "$(@D)/.tmp_$(@F)";)
> 
> In addition, I'm not sure if skipping modules like STACKVALIDATE_foo.o=n
> will still function properly for modversioned modules.

I'm not sure that's really a problem, since I don't think we'll need to
skip validation of any module code.  It's only used for skipping code
which runs outside of the kernel's normal operation (e.g., boot, vdso,
kexec).

-- 
Josh

Re: [PATCH v8 00/21] Compile-time stack validation

[Josh Poimboeuf]

On Wed, Aug 12, 2015 at 04:24:49PM -0500, Chris J Arges wrote:
> I still get build failures and I've pared it down to x86_64 defconfig plus:
> CONFIG_MODVERSIONS=y
> CONFIG_STACK_VALIDATION=y
> 
> And it seems like some modules may get the .tmp_foo.o treatment while
> others end up foo.o so something like the following will not work:
> 
> cmd_stackvalidate = $(if $(patsubst n%,, \
>         $(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \
>         $(__stackvalidate) $(nofp) "$(@D)/.tmp_$(@F)";)

Does this fix it?

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index ec96c51..0181915 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -263,8 +263,8 @@ endif # CONFIG_STACK_VALIDATION
 define rule_cc_o_c
 	$(call echo-cmd,checksrc) $(cmd_checksrc)			  \
 	$(call echo-cmd,cc_o_c) $(cmd_cc_o_c);				  \
-	$(cmd_stackvalidate)						  \
 	$(cmd_modversions)						  \
+	$(cmd_stackvalidate)						  \
 	$(call echo-cmd,record_mcount)					  \
 	$(cmd_record_mcount)						  \
 	scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' >    \

Re: [PATCH v8 00/21] Compile-time stack validation

[Chris J Arges]

On Thu, Aug 13, 2015 at 06:22:20AM -0500, Josh Poimboeuf wrote:
> On Wed, Aug 12, 2015 at 04:24:49PM -0500, Chris J Arges wrote:
> > I still get build failures and I've pared it down to x86_64 defconfig plus:
> > CONFIG_MODVERSIONS=y
> > CONFIG_STACK_VALIDATION=y
> > 
> > And it seems like some modules may get the .tmp_foo.o treatment while
> > others end up foo.o so something like the following will not work:
> > 
> > cmd_stackvalidate = $(if $(patsubst n%,, \
> >         $(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \
> >         $(__stackvalidate) $(nofp) "$(@D)/.tmp_$(@F)";)
> 
> Does this fix it?
> 
> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> index ec96c51..0181915 100644
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -263,8 +263,8 @@ endif # CONFIG_STACK_VALIDATION
>  define rule_cc_o_c
>  	$(call echo-cmd,checksrc) $(cmd_checksrc)			  \
>  	$(call echo-cmd,cc_o_c) $(cmd_cc_o_c);				  \
> -	$(cmd_stackvalidate)						  \
>  	$(cmd_modversions)						  \
> +	$(cmd_stackvalidate)						  \
>  	$(call echo-cmd,record_mcount)					  \
>  	$(cmd_record_mcount)						  \
>  	scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' >    \
>

Josh,

Yes, this fixes my build. For completeness this is my current diff:

diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index a1270d3..0181915 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -243,7 +243,7 @@ endif
 
 ifdef CONFIG_STACK_VALIDATION
 
-stackvalidate = $(objtree)/scripts/stackvalidate/stackvalidate
+__stackvalidate = $(objtree)/scripts/stackvalidate/stackvalidate
 
 ifndef CONFIG_FRAME_POINTER
 nofp = --no-frame-pointer
@@ -251,17 +251,20 @@ endif
 
 # Set STACKVALIDATE_foo.o=n to skip stack validation for a file.
 # Set STACKVALIDATE=n to skip stack validation for a directory.
+stackvalidate = $(if $(patsubst n%,, \
+	$(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \
+	$(__stackvalidate))
 cmd_stackvalidate = $(if $(patsubst n%,, \
 	$(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \
-	$(stackvalidate) $(nofp) "$(@)";)
+	$(__stackvalidate) $(nofp) "$(@)";)
 
 endif # CONFIG_STACK_VALIDATION
 
 define rule_cc_o_c
 	$(call echo-cmd,checksrc) $(cmd_checksrc)			  \
 	$(call echo-cmd,cc_o_c) $(cmd_cc_o_c);				  \
-	$(cmd_stackvalidate)						  \
 	$(cmd_modversions)						  \
+	$(cmd_stackvalidate)						  \
 	$(call echo-cmd,record_mcount)					  \
 	$(cmd_record_mcount)						  \
 	scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' >    \
diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile
index c11212f..374c413 100644
--- a/scripts/mod/Makefile
+++ b/scripts/mod/Makefile
@@ -1,3 +1,5 @@
+STACKVALIDATE	:= n
+
 hostprogs-y	:= modpost mk_elfconfig
 always		:= $(hostprogs-y) empty.o

Thanks,
--chris
 

Re: [PATCH v8 00/21] Compile-time stack validation

[Josh Poimboeuf]

On Thu, Aug 13, 2015 at 09:42:25AM -0500, Chris J Arges wrote:
> On Thu, Aug 13, 2015 at 06:22:20AM -0500, Josh Poimboeuf wrote:
> > On Wed, Aug 12, 2015 at 04:24:49PM -0500, Chris J Arges wrote:
> > > I still get build failures and I've pared it down to x86_64 defconfig plus:
> > > CONFIG_MODVERSIONS=y
> > > CONFIG_STACK_VALIDATION=y
> > > 
> > > And it seems like some modules may get the .tmp_foo.o treatment while
> > > others end up foo.o so something like the following will not work:
> > > 
> > > cmd_stackvalidate = $(if $(patsubst n%,, \
> > >         $(STACKVALIDATE_$(basetarget).o)$(STACKVALIDATE)y), \
> > >         $(__stackvalidate) $(nofp) "$(@D)/.tmp_$(@F)";)
> > 
> > Does this fix it?
> > 
> > diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> > index ec96c51..0181915 100644
> > --- a/scripts/Makefile.build
> > +++ b/scripts/Makefile.build
> > @@ -263,8 +263,8 @@ endif # CONFIG_STACK_VALIDATION
> >  define rule_cc_o_c
> >  	$(call echo-cmd,checksrc) $(cmd_checksrc)			  \
> >  	$(call echo-cmd,cc_o_c) $(cmd_cc_o_c);				  \
> > -	$(cmd_stackvalidate)						  \
> >  	$(cmd_modversions)						  \
> > +	$(cmd_stackvalidate)						  \
> >  	$(call echo-cmd,record_mcount)					  \
> >  	$(cmd_record_mcount)						  \
> >  	scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' >    \
> >
> 
> Josh,
> 
> Yes, this fixes my build. For completeness this is my current diff:

Great!  I'll roll both patches into v10.

-- 
Josh

[PATCH v8 00/21] Compile-time stack validation

[Josh Poimboeuf]

This is v8 of the compile-time stack validation patch set, based on the
tip/master branch.

The frame pointer macros are still called FRAME and ENDFRAME because I
don't think we converged on anything else yet.  Otherwise I tried to
address all the other review comments from v7.

v7 can be found here:

  https://lkml.kernel.org/r/cover.1436893563.git.jpoimboe@redhat.com

For more information about the motivation behind this patch set, and
more details about what it does, please see the changelog in patch 3.

Patches 1-5 are the stackvalidate tool and some related macros.

Patches 6-21 are some proposed fixes for several of the warnings
reported by stackvalidate.  They've been compile-tested and boot tested
in a VM, but I haven't attempted any meaningful testing for many of
them.

v8:
- add proposed fixes for warnings
- fix all memory leaks
- process ignores earlier and add more ignore checks
- always assume POPCNT alternative is enabled
- drop hweight inline asm fix
- drop __schedule() ignore patch
- change .Ltemp_\@ to .Lstackvalidate_ignore_\@ in asm macro
- fix CONFIG_* checks in asm macros
- add C versions of ignore macros and frame macros
- change ";" to "\n" in C macros
- add ifdef CONFIG_STACK_VALIDATION checks in C ignore macros
- use numbered label in C ignore macro
- add missing break in switch case statement in arch-x86.c

v7:
- sibling call support
- document proposed solution for inline asm() frame pointer issues
- say "kernel entry/exit" instead of "context switch"
- clarify the checking of switch statement jump tables
- discard __stackvalidate_ignore_* sections in linker script
- use .Ltemp_\@ to get a unique label instead of static 3-digit number
- change STACKVALIDATE_IGNORE_FUNC variable to a static
- move STACKVALIDATE_IGNORE_INSN to arch-specific .h file

v6:
- rename asmvalidate -> stackvalidate (again)
- gcc-generated object file support
- recursive branch state analysis
- external jump support
- fixup/exception table support
- jump label support
- switch statement jump table support
- added documentation
- detection of "noreturn" dead end functions
- added a Kbuild mechanism for skipping files and dirs
- moved frame pointer macros to arch/x86/include/asm/frame.h
- moved ignore macros to include/linux/stackvalidate.h

v5:
- stackvalidate -> asmvalidate
- frame pointers only required for non-leaf functions
- check for the use of the FP_SAVE/RESTORE macros instead of manually
  analyzing code to detect frame pointer usage
- additional checks to ensure each function doesn't leave its boundaries
- make the macros simpler and more flexible
- support for analyzing ALTERNATIVE macros
- simplified the arch interfaces in scripts/asmvalidate/arch.h
- fixed some asmvalidate warnings
- rebased onto latest tip asm cleanups
- many more small changes

v4:
- Changed the default to CONFIG_STACK_VALIDATION=n, until all the asm
  code can get cleaned up.
- Fixed a stackvalidate error path exit code issue found by Michal
  Marek.

v3:
- Added a patch to make the push/pop CFI macros arch-independent, as
  suggested by H. Peter Anvin

v2:
- Fixed memory leaks reported by Petr Mladek

Josh Poimboeuf (21):
  x86/asm: Frame pointer macro cleanup
  x86/asm: Add C versions of FRAME and ENDFRAME macros
  x86/stackvalidate: Compile-time stack validation
  x86/stackvalidate: Add file and directory ignores
  x86/stackvalidate: Add ignore macros
  x86/xen: Add stack frame dependency to hypercall inline asm calls
  x86/paravirt: Add stack frame dependency to PVOP inline asm calls
  x86/paravirt: Fix frame pointer usage in PV_CALLEE_SAVE_REGS_THUNK
  x86/paravirt: Align paravirt thunk functions at 16-byte boundaries
  x86/amd: Set ELF function type for vide()
  x86/reboot: Add ljmp instructions to stackvalidate whitelist
  x86/xen: Add xen_cpuid() and xen_setup_gdt() to stackvalidate
    whitelists
  x86/asm/crypto: Fix frame pointer usage in aesni-intel_asm.S
  x86/asm/crypto: Move .Lbswap_mask data to .rodata section
  x86/asm/crypto: Move jump_table to .rodata section
  x86/asm/crypto: Fix frame pointer usage in clmul_ghash_mul/update()
  x86/asm/entry: Fix frame pointer usage in thunk functions
  x86/asm/acpi: Fix frame pointer usage in do_suspend_lowlevel()
  x86/asm: Fix frame pointer usage in rwsem functions
  x86/asm/efi: Fix frame pointer usage in efi_call()
  x86/asm/power: Fix frame pointer usage in hibernate_asm_64.S

 Documentation/stack-validation.txt        | 193 ++++++
 MAINTAINERS                               |   8 +
 arch/Kconfig                              |   6 +
 arch/x86/Kconfig                          |   1 +
 arch/x86/Makefile                         |   6 +-
 arch/x86/boot/Makefile                    |   3 +-
 arch/x86/boot/compressed/Makefile         |   3 +-
 arch/x86/crypto/aesni-intel_asm.S         |  21 +
 arch/x86/crypto/crc32c-pcl-intel-asm_64.S |   8 +-
 arch/x86/crypto/ghash-clmulni-intel_asm.S |   5 +
 arch/x86/entry/thunk_64.S                 |   4 +
 arch/x86/entry/vdso/Makefile              |   5 +-
 arch/x86/include/asm/frame.h              |  51 +-
 arch/x86/include/asm/paravirt.h           |  10 +-
 arch/x86/include/asm/paravirt_types.h     |  18 +-
 arch/x86/include/asm/stackvalidate.h      |  45 ++
 arch/x86/include/asm/xen/hypercall.h      |   5 +-
 arch/x86/kernel/acpi/wakeup_64.S          |   3 +
 arch/x86/kernel/cpu/amd.c                 |   5 +-
 arch/x86/kernel/reboot.c                  |   7 +-
 arch/x86/kernel/vmlinux.lds.S             |   5 +-
 arch/x86/lib/rwsem.S                      |  11 +-
 arch/x86/platform/efi/efi_stub_64.S       |   3 +
 arch/x86/power/hibernate_asm_64.S         |   7 +
 arch/x86/purgatory/Makefile               |   2 +
 arch/x86/realmode/Makefile                |   4 +-
 arch/x86/realmode/rm/Makefile             |   3 +-
 arch/x86/xen/enlighten.c                  |   4 +-
 drivers/firmware/efi/libstub/Makefile     |   1 +
 include/linux/stackvalidate.h             |  28 +
 lib/Kconfig.debug                         |  11 +
 scripts/Makefile                          |   1 +
 scripts/Makefile.build                    |  34 +-
 scripts/stackvalidate/Makefile            |  24 +
 scripts/stackvalidate/arch-x86.c          | 160 +++++
 scripts/stackvalidate/arch.h              |  44 ++
 scripts/stackvalidate/elf.c               | 427 ++++++++++++++
 scripts/stackvalidate/elf.h               |  92 +++
 scripts/stackvalidate/list.h              | 217 +++++++
 scripts/stackvalidate/special.c           | 197 +++++++
 scripts/stackvalidate/special.h           |  41 ++
 scripts/stackvalidate/stackvalidate.c     | 949 ++++++++++++++++++++++++++++++
 42 files changed, 2624 insertions(+), 48 deletions(-)
 create mode 100644 Documentation/stack-validation.txt
 create mode 100644 arch/x86/include/asm/stackvalidate.h
 create mode 100644 include/linux/stackvalidate.h
 create mode 100644 scripts/stackvalidate/Makefile
 create mode 100644 scripts/stackvalidate/arch-x86.c
 create mode 100644 scripts/stackvalidate/arch.h
 create mode 100644 scripts/stackvalidate/elf.c
 create mode 100644 scripts/stackvalidate/elf.h
 create mode 100644 scripts/stackvalidate/list.h
 create mode 100644 scripts/stackvalidate/special.c
 create mode 100644 scripts/stackvalidate/special.h
 create mode 100644 scripts/stackvalidate/stackvalidate.c

-- 
2.1.0

Re: [PATCH v8 00/21] Compile-time stack validation

[Ingo Molnar]

* Josh Poimboeuf <jpoimboe@redhat.com> wrote:

> This is v8 of the compile-time stack validation patch set, based on the
> tip/master branch.
> 
> The frame pointer macros are still called FRAME and ENDFRAME because I
> don't think we converged on anything else yet.  Otherwise I tried to
> address all the other review comments from v7.

So I think:

	FRAME_START
	FRAME_END

would be OK.

They could be added as new aliases, keeping the old ones as well, while in the new 
patches you should use this new form.

Thanks,

	Ingo

Re: [PATCH v8 00/21] Compile-time stack validation

[Josh Poimboeuf]

On Thu, Aug 06, 2015 at 10:07:50AM +0200, Ingo Molnar wrote:
> 
> * Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> 
> > This is v8 of the compile-time stack validation patch set, based on the
> > tip/master branch.
> > 
> > The frame pointer macros are still called FRAME and ENDFRAME because I
> > don't think we converged on anything else yet.  Otherwise I tried to
> > address all the other review comments from v7.
> 
> So I think:
> 
> 	FRAME_START
> 	FRAME_END
> 
> would be OK.

Thanks, that sounds good to me.

> They could be added as new aliases, keeping the old ones as well, while in the new 
> patches you should use this new form.

Turns out nobody uses the existing FRAME/ENDFRAME macros, so I'll just
rename them.

-- 
Josh

Re: [PATCH v8 00/21] Compile-time stack validation

[Josh Poimboeuf]

On Thu, Aug 06, 2015 at 10:07:50AM +0200, Ingo Molnar wrote:
> 
> * Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> 
> > This is v8 of the compile-time stack validation patch set, based on the
> > tip/master branch.
> > 
> > The frame pointer macros are still called FRAME and ENDFRAME because I
> > don't think we converged on anything else yet.  Otherwise I tried to
> > address all the other review comments from v7.
> 
> So I think:
> 
> 	FRAME_START
> 	FRAME_END

(One last tweak to the bikeshed)

The antonym of END is BEGIN.  So how about:

  FRAME_BEGIN
  FRAME_END


-- 
Josh

Re: [PATCH v8 00/21] Compile-time stack validation

[Josh Poimboeuf]

On Thu, Aug 06, 2015 at 12:23:32PM -0500, Josh Poimboeuf wrote:
> On Thu, Aug 06, 2015 at 10:07:50AM +0200, Ingo Molnar wrote:
> > 
> > * Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> > 
> > > This is v8 of the compile-time stack validation patch set, based on the
> > > tip/master branch.
> > > 
> > > The frame pointer macros are still called FRAME and ENDFRAME because I
> > > don't think we converged on anything else yet.  Otherwise I tried to
> > > address all the other review comments from v7.
> > 
> > So I think:
> > 
> > 	FRAME_START
> > 	FRAME_END
> 
> (One last tweak to the bikeshed)
> 
> The antonym of END is BEGIN.  So how about:
> 
>   FRAME_BEGIN
>   FRAME_END

Ok, so thesaurus.com reminds me that words can have more than one
antonym, and that START and BEGIN are both antonyms of END.

Personally, when I START something I usually FINISH it or even STOP it.

So I'll stop the bikeshedding I started and go with BEGIN/END.

-- 
Josh