Hi,
After I discovered libsepol/cil happened to use "%n" in printf format
string, I decided to compile SELinux userland libraries and tools with
more compilation flags. I used:
CFLAGS = -O2 -pipe -Wall -Wextra -Werror \
-D_FORTIFY_SOURCE=2 \
-Wfloat-equal \
-Wformat -Wformat-security \
-Winit-self \
-Wmissing-declarations \
-Wpointer-arith \
-Wshadow \
-Wsign-compare \
-Wstrict-prototypes \
-Wwrite-strings \
-Wno-unused-result \
-fno-exceptions \
-fstack-protector --param=ssp-buffer-size=4
LDFLAGS = -Wl,-as-needed,-no-undefined,-z,relro,-z,now \
-fstack-protector
These warning flags are described in
https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html.
The build is broken when using all of these flags and this patchset is
an attempt to fix some warnings/errors. Here is what I found:
* Combining "-O2 -Wall -Werror" made the build fail because of use of
unitialized variables. Patches 1, 2 and 3 fix this.
* -Wshadow is already enabled when doing "make DEBUG=1" but this did not
prevent some programs from shadowing global variables. Patches 4 and
5 fix this.
* To make "-Wformat -Wformat-security" useful, a format attribute should
be added to logging functions. When doing such a thing, gcc warns
about some format string. Patches 6 and 7 add the attribute and fixes
some new warnings.
* While at it, checkpolicy logging function used "char *message" instead
of "const char *message". Patch 8 modifies this.
* -Wsign-compare makes gcc complains on some implicit casts. Patches 9,
10 and 11 fix the generated warnings.
* -Wwrite-strings makes gcc complains when using code like:
char *s = "text"
Here, s is a pointer to a read-only location and should be made
"const char*". Patches 12 to 17 fix most of these warnings. Some of
them cannot be fixed without changing the API defined in
/usr/include/sepol/policydb/hashtab.h (in short: replacing "const
hashtab_key_t k" with "const char *k"). As this patchset focuses on
fixing internal things, this API has not been changed.
* -Wstrict-prototypes complained about some functions defined with an
empty argument list instead of (void). Patch 18 adds the missing
arguments and marks them with __attribute__ ((unused)) when
applicable.
* -Wunused-variable (from -Wall) made gcc complain about unused
parameters in checkpolicy/. Patch 19 adds some __attribute__
((unused)).
* -Wmissing-declarations helps finding missing "static" keyword when
defining functions and missing headers when the function is willingly
non-static. There are too many warnings caused by this flag to make
it useful.
* Last but not the least, when testing with "make test", gcc complained
with -Warray-bounds warning because libsepol/tests/test-linker-roles.c
had:
unsigned int decls[2]
/* ... */
decls[2] = ...
... Patch 20 replaces the first "2" by "3" to fix this bug.
With this patchset, the build succeeds when using the given CFLAGS
configuration without -Wwrite-strings and -Wmissing-declarations.
The linker_roles test from libsepol fails because CIL changed the way
roles in base policy are managed:
Suite: linker
Test: linker_indexes ...passed
Test: linker_types ...passed
Test: linker_roles ...
role o1_b_role_1 has 0 types, 1 expected
[[SNIP]]
FAILED
This failure has not been introduced by this patchset and this patchset
does not fix the test nor introduces new failures.
Cheers
Nicolas Iooss (20):
libsepol: fix potential free of uninitialized pointer
libsemanage: Fix use of unitialized variable
policycoreutils/hll/pp: fix potential use of uninitialized variable
policycoreutils/sandbox: fix debug build
policycoreutils/semodule_package: fix debug build
policycoreutils/hll/pp: add printf format attribute to relevant
functions
checkpolicy: add printf format attribute to relevant functions
checkpolicy: constify the message written by yyerror and yywarn
libselinux: fix gcc -Wsign-compare warnings
checkpolicy: fix gcc -Wsign-compare warnings
libsepol: fix most gcc -Wwrite-strings warnings
libsemanage: constify name and ext_lang parameters of
semanage_module_install_hll
libsepol/cil: fix gcc -Wwrite-strings warnings
libsemanage: fix gcc -Wwrite-strings warnings
checkpolicy: fix most gcc -Wwrite-strings warnings
policycoreutils/hll/pp: fix gcc -Wwrite-strings warnings
policycoreutils: fix most gcc -Wwrite-strings warnings
Fix gcc -Wstrict-prototypes warnings
checkpolicy: fix gcc -Wunused-variable warnings
libsepol/tests: fix gcc -Warray-bounds warning
checkpolicy/checkmodule.c | 10 ++--
checkpolicy/checkpolicy.c | 15 +++---
checkpolicy/module_compiler.c | 13 ++---
checkpolicy/policy_define.c | 33 ++++++------
checkpolicy/policy_define.h | 2 +-
checkpolicy/policy_parse.y | 6 +--
checkpolicy/policy_scan.l | 8 +--
checkpolicy/test/dismod.c | 6 +--
checkpolicy/test/dispol.c | 8 +--
libselinux/src/label_file.c | 9 ++--
libselinux/src/label_file.h | 2 +-
libselinux/utils/sefcontext_compile.c | 4 +-
libsemanage/src/conf-parse.y | 6 +--
libsemanage/src/direct_api.c | 4 +-
libsemanage/src/modules.c | 2 +-
libsemanage/src/modules.h | 2 +-
libsemanage/src/policy.h | 2 +-
libsemanage/src/seusers_local.c | 3 +-
libsemanage/src/utilities.c | 6 +--
libsemanage/src/utilities.h | 6 +--
libsepol/cil/src/cil.c | 2 +-
libsepol/cil/src/cil_mem.c | 2 +-
libsepol/cil/src/cil_mem.h | 2 +-
libsepol/cil/src/cil_policy.c | 10 ++--
libsepol/cil/src/cil_strpool.c | 2 +-
libsepol/cil/src/cil_strpool.h | 2 +-
libsepol/include/sepol/policydb/services.h | 2 +-
libsepol/src/link.c | 6 +--
libsepol/src/policydb.c | 2 +-
libsepol/src/policydb_internal.h | 2 +-
libsepol/src/services.c | 22 ++++----
libsepol/src/write.c | 2 +-
libsepol/tests/test-linker-roles.c | 2 +-
policycoreutils/hll/pp/pp.c | 61 ++++++++++++----------
policycoreutils/newrole/newrole.c | 6 +--
policycoreutils/restorecond/restorecond.c | 8 +--
policycoreutils/restorecond/restorecond.h | 2 +-
policycoreutils/restorecond/user.c | 2 +-
policycoreutils/restorecond/utmpwatcher.c | 2 +-
policycoreutils/restorecond/watch.c | 2 +-
policycoreutils/run_init/run_init.c | 2 +-
policycoreutils/sandbox/seunshare.c | 12 ++---
.../semodule_package/semodule_package.c | 6 +--
.../semodule_package/semodule_unpackage.c | 6 +--
policycoreutils/setfiles/restore.h | 4 +-
policycoreutils/setfiles/setfiles.c | 6 +--
46 files changed, 169 insertions(+), 155 deletions(-)
--
2.1.0
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