| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20120214151312.92afd44a.akpm@linux-foundation.org> Date: Tue, 14 Feb 2012 15:13:12 -0800 From: Andrew Morton <akpm@...ux-foundation.org> To: Cyrill Gorcunov <gorcunov@...nvz.org> Cc: linux-kernel@...r.kernel.org, "Eric W. Biederman" <ebiederm@...ssion.com>, Pavel Emelyanov <xemul@...nvz.org>, KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>, Ingo Molnar <mingo@...e.hu>, "H. Peter Anvin" <hpa@...or.com>, Pavel Emelyanov <xemul@...allels.com>, Andrey Vagin <avagin@...nvz.org>, KOSAKI Motohiro <kosaki.motohiro@...il.com>, Thomas Gleixner <tglx@...utronix.de>, Glauber Costa <glommer@...allels.com>, Andi Kleen <andi@...stfloor.org>, Tejun Heo <tj@...nel.org>, Matt Helsley <matthltc@...ibm.com>, Pekka Enberg <penberg@...nel.org>, Eric Dumazet <eric.dumazet@...il.com>, Vasiliy Kulikov <segoon@...nwall.com>, Alexey Dobriyan <adobriyan@...il.com>, Valdis.Kletnieks@...edu, Michal Marek <mmarek@...e.cz> Subject: Re: [patch 2/4] syscalls, x86: Add __NR_kcmp syscall v8 On Mon, 13 Feb 2012 20:48:24 +0400 Cyrill Gorcunov <gorcunov@...nvz.org> wrote: > While doing the checkpoint-restore in the user space one need to determine > whether various kernel objects (like mm_struct-s of file_struct-s) are shared > between tasks and restore this state. > > The 2nd step can be solved by using appropriate CLONE_ flags and the unshare > syscall, while there's currently no ways for solving the 1st one. > > One of the ways for checking whether two tasks share e.g. mm_struct is to > provide some mm_struct ID of a task to its proc file, but showing such > info considered to be not that good for security reasons. > > Thus after some debates we end up in conclusion that using that named > 'comparison' syscall might be the best candidate. So here is it -- > __NR_kcmp. > > It takes up to 5 arguments - the pids of the two tasks (which > characteristics should be compared), the comparison type and > (in case of comparison of files) two file descriptors. > > Lookups for pids are done in the caller's PID namespace only. > > At moment only x86 is supported and tested. > > > ... > > --- /dev/null > +++ linux-2.6.git/tools/testing/selftests/kcmp/Makefile > @@ -0,0 +1,36 @@ > +ifeq ($(strip $(V)),) > + E = @echo > + Q = @ > +else > + E = @\# > + Q = > +endif > +export E Q > + > +uname_M := $(shell uname -m 2>/dev/null || echo not) > +ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/i386/) > +ifeq ($(ARCH),i386) > + ARCH := X86 > + CFLAGS := -DCONFIG_X86_32 -D__i386__ > +endif > +ifeq ($(ARCH),x86_64) > + ARCH := X86 > + CFLAGS := -DCONFIG_X86_64 -D__x86_64__ > +endif > + > +CFLAGS += -I../../../../arch/x86/include/generated/ > +CFLAGS += -I../../../../include/ > +CFLAGS += -I../../../../usr/include/ > + > +all: > +ifeq ($(ARCH),X86) > + $(E) " CC run_test" > + $(Q) gcc $(CFLAGS) kcmp_test.c -o run_test > +else > + $(E) "Not an x86 target, can't build kcmp selftest" > +endif > + > +clean: > + $(E) " CLEAN" > + $(Q) rm -fr ./run_test > + $(Q) rm -fr ./test-file hm, what does all this stuff in the selftest makefile do? The selftests code has undergone some changes since you last looked. The rules are, roughly: - In tools/testing/selftests, a "make" will compile but not run all selftest code. - In tools/testing/selftests, a "make run_tests" will compile all selftest code (if needed) and will then run all the tests. If a test is not applicable (eg wrong architecture, kernel feature not enabled, etc) then it should try to avoid breaking the build and, when executed it should emit a diagnostic and then exit(0) (ie: success) so as to avoid breaking the overall test run. IOW, the test should only fail if the feature is present but isn't working correctly. Also, I hate with a passion Makefiles which hide the command lines from me! So I nuked all that E and Q stuff. Result: --- a/tools/testing/selftests/kcmp/Makefile~syscalls-x86-add-__nr_kcmp-syscall-v8-fix +++ a/tools/testing/selftests/kcmp/Makefile @@ -1,12 +1,3 @@ -ifeq ($(strip $(V)),) - E = @echo - Q = @ -else - E = @\# - Q = -endif -export E Q - uname_M := $(shell uname -m 2>/dev/null || echo not) ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/i386/) ifeq ($(ARCH),i386) @@ -24,13 +15,14 @@ CFLAGS += -I../../../../usr/include/ all: ifeq ($(ARCH),X86) - $(E) " CC run_test" - $(Q) gcc $(CFLAGS) kcmp_test.c -o run_test + gcc $(CFLAGS) kcmp_test.c -o run_test else - $(E) "Not an x86 target, can't build kcmp selftest" + echo "Not an x86 target, can't build kcmp selftest" endif +run-tests: all + ./kcmp_test + clean: - $(E) " CLEAN" - $(Q) rm -fr ./run_test - $(Q) rm -fr ./test-file + rm -fr ./run_test + rm -fr ./test-file --- a/tools/testing/selftests/Makefile~syscalls-x86-add-__nr_kcmp-syscall-v8-fix +++ a/tools/testing/selftests/Makefile @@ -1,4 +1,4 @@ -TARGETS = breakpoints vm +TARGETS = breakpoints vm kcmp all: for TARGET in $(TARGETS); do \ _ However that didn't work for me: akpm:/usr/src/25/tools/testing/selftests/kcmp> make gcc -DCONFIG_X86_64 -D__x86_64__ -I../../../../arch/x86/include/generated/ -I../../../../include/ -I../../../../usr/include/ kcmp_test.c -o run_test kcmp_test.c: In function 'sys_kcmp': kcmp_test.c:22: error: '__NR_kcmp' undeclared (first use in this function) kcmp_test.c:22: error: (Each undeclared identifier is reported only once kcmp_test.c:22: error: for each function it appears in.) kcmp_test.c: In function 'main': kcmp_test.c:69: warning: format '%2d' expects type 'int', but argument 4 has type 'long int' kcmp_test.c:69: warning: format '%2d' expects type 'int', but argument 5 has type 'long int' kcmp_test.c:69: warning: format '%2d' expects type 'int', but argument 6 has type 'long int' kcmp_test.c:69: warning: format '%2d' expects type 'int', but argument 7 has type 'long int' kcmp_test.c:69: warning: format '%2d' expects type 'int', but argument 8 has type 'long int' kcmp_test.c:69: warning: format '%2d' expects type 'int', but argument 9 has type 'long int' kcmp_test.c:69: warning: format '%2d' expects type 'int', but argument 10 has type 'long int' kcmp_test.c:69: warning: format '%2d' expects type 'int', but argument 11 has type 'long int' How are we supposed to be picking up __NR_kcmp? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists