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.
Signed-off-by: Cyrill Gorcunov <[email protected]>
CC: "Eric W. Biederman" <[email protected]>
CC: Pavel Emelyanov <[email protected]>
CC: Andrey Vagin <[email protected]>
CC: KOSAKI Motohiro <[email protected]>
CC: Ingo Molnar <[email protected]>
CC: H. Peter Anvin <[email protected]>
CC: Thomas Gleixner <[email protected]>
CC: Glauber Costa <[email protected]>
CC: Andi Kleen <[email protected]>
CC: Tejun Heo <[email protected]>
CC: Matt Helsley <[email protected]>
CC: Pekka Enberg <[email protected]>
CC: Eric Dumazet <[email protected]>
CC: Vasiliy Kulikov <[email protected]>
CC: Andrew Morton <[email protected]>
CC: Alexey Dobriyan <[email protected]>
CC: [email protected]
CC: Michal Marek <[email protected]>
---
arch/x86/syscalls/syscall_32.tbl | 1
arch/x86/syscalls/syscall_64.tbl | 1
include/linux/kcmp.h | 17 +++
include/linux/syscalls.h | 2
kernel/Makefile | 3
kernel/kcmp.c | 155 +++++++++++++++++++++++++++++++
kernel/sys_ni.c | 3
tools/testing/selftests/kcmp/Makefile | 36 +++++++
tools/testing/selftests/kcmp/kcmp_test.c | 84 ++++++++++++++++
tools/testing/selftests/run_tests | 2
10 files changed, 303 insertions(+), 1 deletion(-)
Index: linux-2.6.git/arch/x86/syscalls/syscall_32.tbl
===================================================================
--- linux-2.6.git.orig/arch/x86/syscalls/syscall_32.tbl
+++ linux-2.6.git/arch/x86/syscalls/syscall_32.tbl
@@ -355,3 +355,4 @@
346 i386 setns sys_setns
347 i386 process_vm_readv sys_process_vm_readv compat_sys_process_vm_readv
348 i386 process_vm_writev sys_process_vm_writev compat_sys_process_vm_writev
+349 i386 kcmp sys_kcmp
Index: linux-2.6.git/arch/x86/syscalls/syscall_64.tbl
===================================================================
--- linux-2.6.git.orig/arch/x86/syscalls/syscall_64.tbl
+++ linux-2.6.git/arch/x86/syscalls/syscall_64.tbl
@@ -318,3 +318,4 @@
309 64 getcpu sys_getcpu
310 64 process_vm_readv sys_process_vm_readv
311 64 process_vm_writev sys_process_vm_writev
+312 64 kcmp sys_kcmp
Index: linux-2.6.git/include/linux/kcmp.h
===================================================================
--- /dev/null
+++ linux-2.6.git/include/linux/kcmp.h
@@ -0,0 +1,17 @@
+#ifndef _LINUX_KCMP_H
+#define _LINUX_KCMP_H
+
+/* Comparison type */
+enum kcmp_type {
+ KCMP_FILE,
+ KCMP_VM,
+ KCMP_FILES,
+ KCMP_FS,
+ KCMP_SIGHAND,
+ KCMP_IO,
+ KCMP_SYSVSEM,
+
+ KCMP_TYPES,
+};
+
+#endif /* _LINUX_KCMP_H */
Index: linux-2.6.git/include/linux/syscalls.h
===================================================================
--- linux-2.6.git.orig/include/linux/syscalls.h
+++ linux-2.6.git/include/linux/syscalls.h
@@ -857,4 +857,6 @@ asmlinkage long sys_process_vm_writev(pi
unsigned long riovcnt,
unsigned long flags);
+asmlinkage long sys_kcmp(pid_t pid1, pid_t pid2, int type,
+ unsigned long idx1, unsigned long idx2);
#endif
Index: linux-2.6.git/kernel/Makefile
===================================================================
--- linux-2.6.git.orig/kernel/Makefile
+++ linux-2.6.git/kernel/Makefile
@@ -25,6 +25,9 @@ endif
obj-y += sched/
obj-y += power/
+ifeq ($(CONFIG_CHECKPOINT_RESTORE),y)
+obj-$(CONFIG_X86) += kcmp.o
+endif
obj-$(CONFIG_FREEZER) += freezer.o
obj-$(CONFIG_PROFILING) += profile.o
obj-$(CONFIG_SYSCTL_SYSCALL_CHECK) += sysctl_check.o
Index: linux-2.6.git/kernel/kcmp.c
===================================================================
--- /dev/null
+++ linux-2.6.git/kernel/kcmp.c
@@ -0,0 +1,155 @@
+#include <linux/kernel.h>
+#include <linux/syscalls.h>
+#include <linux/fdtable.h>
+#include <linux/string.h>
+#include <linux/random.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/cache.h>
+#include <linux/bug.h>
+#include <linux/err.h>
+#include <linux/kcmp.h>
+
+#include <asm/unistd.h>
+
+/*
+ * We don't expose real in-memory order of objects for security
+ * reasons, still the comparison results should be suitable for
+ * sorting. Thus, we obfuscate kernel pointers values and compare
+ * the production instead.
+ */
+static unsigned long cookies[KCMP_TYPES][2] __read_mostly;
+
+static long kptr_obfuscate(long v, int type)
+{
+ return (v ^ cookies[type][0]) * cookies[type][1];
+}
+
+/*
+ * 0 - equal, i.e. v1 = v2
+ * 1 - less than, i.e. v1 < v2
+ * 2 - greater than, i.e. v1 > v2
+ * 3 - not equal but ordering unavailable (reserved for future)
+ */
+static int kcmp_ptr(void *v1, void *v2, enum kcmp_type type)
+{
+ long ret;
+
+ ret = kptr_obfuscate((long)v1, type) - kptr_obfuscate((long)v2, type);
+
+ return (ret < 0) | ((ret > 0) << 1);
+}
+
+/* The caller must have pinned the task */
+static struct file *
+get_file_raw_ptr(struct task_struct *task, unsigned int idx)
+{
+ struct fdtable *fdt;
+ struct file *file;
+
+ spin_lock(&task->files->file_lock);
+ fdt = files_fdtable(task->files);
+ if (idx < fdt->max_fds)
+ file = fdt->fd[idx];
+ else
+ file = NULL;
+ spin_unlock(&task->files->file_lock);
+
+ return file;
+}
+
+SYSCALL_DEFINE5(kcmp, pid_t, pid1, pid_t, pid2, int, type,
+ unsigned long, idx1, unsigned long, idx2)
+{
+ struct task_struct *task1, *task2;
+ int ret;
+
+ rcu_read_lock();
+
+ /*
+ * Tasks are looked up in caller's PID namespace only.
+ */
+ task1 = find_task_by_vpid(pid1);
+ task2 = find_task_by_vpid(pid2);
+ if (!task1 || !task2)
+ goto err_no_task;
+
+ get_task_struct(task1);
+ get_task_struct(task2);
+
+ rcu_read_unlock();
+
+ /*
+ * One should have enough rights to inspect task details.
+ */
+ if (!ptrace_may_access(task1, PTRACE_MODE_READ) ||
+ !ptrace_may_access(task2, PTRACE_MODE_READ)) {
+ ret = -EACCES;
+ goto err;
+ }
+
+ switch (type) {
+ case KCMP_FILE: {
+ struct file *filp1, *filp2;
+
+ filp1 = get_file_raw_ptr(task1, idx1);
+ filp2 = get_file_raw_ptr(task2, idx2);
+
+ if (filp1 && filp2)
+ ret = kcmp_ptr(filp1, filp2, KCMP_FILE);
+ else
+ ret = -EBADF;
+ break;
+ }
+ case KCMP_VM:
+ ret = kcmp_ptr(task1->mm, task2->mm, KCMP_VM);
+ break;
+ case KCMP_FILES:
+ ret = kcmp_ptr(task1->files, task2->files, KCMP_FILES);
+ break;
+ case KCMP_FS:
+ ret = kcmp_ptr(task1->fs, task2->fs, KCMP_FS);
+ break;
+ case KCMP_SIGHAND:
+ ret = kcmp_ptr(task1->sighand, task2->sighand, KCMP_SIGHAND);
+ break;
+ case KCMP_IO:
+ ret = kcmp_ptr(task1->io_context, task2->io_context, KCMP_IO);
+ break;
+ case KCMP_SYSVSEM:
+#ifdef CONFIG_SYSVIPC
+ ret = kcmp_ptr(task1->sysvsem.undo_list,
+ task2->sysvsem.undo_list,
+ KCMP_SYSVSEM);
+#else
+ ret = -EOPNOTSUP;
+#endif
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+err:
+ put_task_struct(task1);
+ put_task_struct(task2);
+
+ return ret;
+
+err_no_task:
+ rcu_read_unlock();
+ return -ESRCH;
+}
+
+static __init int kcmp_cookies_init(void)
+{
+ int i;
+
+ get_random_bytes(cookies, sizeof(cookies));
+
+ for (i = 0; i < KCMP_TYPES; i++)
+ cookies[i][1] |= (~(~0UL >> 1) | 1);
+
+ return 0;
+}
+arch_initcall(kcmp_cookies_init);
Index: linux-2.6.git/kernel/sys_ni.c
===================================================================
--- linux-2.6.git.orig/kernel/sys_ni.c
+++ linux-2.6.git/kernel/sys_ni.c
@@ -203,3 +203,6 @@ cond_syscall(sys_fanotify_mark);
cond_syscall(sys_name_to_handle_at);
cond_syscall(sys_open_by_handle_at);
cond_syscall(compat_sys_open_by_handle_at);
+
+/* compare kernel pointers */
+cond_syscall(sys_kcmp);
Index: linux-2.6.git/tools/testing/selftests/kcmp/Makefile
===================================================================
--- /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
Index: linux-2.6.git/tools/testing/selftests/kcmp/kcmp_test.c
===================================================================
--- /dev/null
+++ linux-2.6.git/tools/testing/selftests/kcmp/kcmp_test.c
@@ -0,0 +1,84 @@
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <limits.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <fcntl.h>
+
+#include <linux/unistd.h>
+#include <linux/kcmp.h>
+
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+
+static long sys_kcmp(int pid1, int pid2, int type, int fd1, int fd2)
+{
+ return syscall(__NR_kcmp, pid1, pid2, type, fd1, fd2);
+}
+
+int main(int argc, char **argv)
+{
+ const char kpath[] = "kcmp-test-file";
+ int pid1, pid2;
+ int fd1, fd2;
+ int status;
+
+ fd1 = open(kpath, O_RDWR | O_CREAT | O_TRUNC, 0644);
+ pid1 = getpid();
+
+ if (fd1 < 0) {
+ perror("Can't create file");
+ exit(1);
+ }
+
+ pid2 = fork();
+ if (pid2 < 0) {
+ perror("fork failed");
+ exit(1);
+ }
+
+ if (!pid2) {
+ int pid2 = getpid();
+ int ret;
+
+ fd2 = open(kpath, O_RDWR, 0644);
+ if (fd2 < 0) {
+ perror("Can't open file");
+ exit(1);
+ }
+
+ /* An example of output and arguments */
+ printf("pid1: %6d pid2: %6d FD: %2d FILES: %2d VM: %2d FS: %2d "
+ "SIGHAND: %2d IO: %2d SYSVSEM: %2d INV: %2d\n",
+ pid1, pid2,
+ sys_kcmp(pid1, pid2, KCMP_FILE, fd1, fd2),
+ sys_kcmp(pid1, pid2, KCMP_FILES, 0, 0),
+ sys_kcmp(pid1, pid2, KCMP_VM, 0, 0),
+ sys_kcmp(pid1, pid2, KCMP_FS, 0, 0),
+ sys_kcmp(pid1, pid2, KCMP_SIGHAND, 0, 0),
+ sys_kcmp(pid1, pid2, KCMP_IO, 0, 0),
+ sys_kcmp(pid1, pid2, KCMP_SYSVSEM, 0, 0),
+
+ /* This one should fail */
+ sys_kcmp(pid1, pid2, KCMP_TYPES + 1, 0, 0));
+
+ /* This one should return same fd */
+ ret = sys_kcmp(pid1, pid2, KCMP_FILE, fd1, fd1);
+ if (ret) {
+ printf("FAIL: 0 expected but %d returned\n", ret);
+ ret = -1;
+ } else
+ printf("PASS: 0 returned as expected\n");
+ exit(ret);
+ }
+
+ waitpid(pid2, &status, P_ALL);
+
+ return 0;
+}
Index: linux-2.6.git/tools/testing/selftests/run_tests
===================================================================
--- linux-2.6.git.orig/tools/testing/selftests/run_tests
+++ linux-2.6.git/tools/testing/selftests/run_tests
@@ -1,6 +1,6 @@
#!/bin/bash
-TARGETS=breakpoints
+TARGETS="breakpoints kcmp"
for TARGET in $TARGETS
do
On Mon, 13 Feb 2012 20:48:24 +0400
Cyrill Gorcunov <[email protected]> wrote:
> While doing the checkpoint-restore in the user space one need to determine
> whether various kernel objects (like mm_struct-s of file_struct-s) are shared
> between tasks and restore this state.
>
> The 2nd step can be solved by using appropriate CLONE_ flags and the unshare
> syscall, while there's currently no ways for solving the 1st one.
>
> One of the ways for checking whether two tasks share e.g. mm_struct is to
> provide some mm_struct ID of a task to its proc file, but showing such
> info considered to be not that good for security reasons.
>
> Thus after some debates we end up in conclusion that using that named
> 'comparison' syscall might be the best candidate. So here is it --
> __NR_kcmp.
>
> It takes up to 5 arguments - the pids of the two tasks (which
> characteristics should be compared), the comparison type and
> (in case of comparison of files) two file descriptors.
>
> Lookups for pids are done in the caller's PID namespace only.
>
> At moment only x86 is supported and tested.
>
>
> ...
>
> --- /dev/null
> +++ linux-2.6.git/tools/testing/selftests/kcmp/Makefile
> @@ -0,0 +1,36 @@
> +ifeq ($(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?
On Tue, Feb 14, 2012 at 03:13:12PM -0800, Andrew Morton wrote:
...
>
> hm, what does all this stuff in the selftest makefile do?
>
> The selftests code has undergone some changes since you last looked.
Hmm, thanks for pointing.
> 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.
>
make V=1 will show the command line, I tried to make the output to look
the same as in case of building kernel.
>
> 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/ ...
> kcmp_test.c: In function 'sys_kcmp':
> kcmp_test.c:22: error: '__NR_kcmp' undeclared (first use in this function)
...
> How are we supposed to be picking up __NR_kcmp?
>
Initially I made it to look into arch/x86 directory and find __NR_kcmp
definition there but then I realised (and someone pointed me as
well) that headers should be taken from those which are generated
by kernel, ie the result of 'make headers_install'. So if you run
make headers_install then the test program should work. If this is
wrong, I can fix it and make a patch on top.
Ie instead of
+#include <linux/unistd.h>
there will be
+#ifdef CONFIG_X86_64
+#include <asm/unistd_64.h>
+#else
+#include <asm/unistd_32.h>
+#endif
Cyrill
What? <linux/unistd.h> should be used, and it should handle the.inclusions.
Cyrill Gorcunov <[email protected]> wrote:
>On Tue, Feb 14, 2012 at 03:13:12PM -0800, Andrew Morton wrote:
>...
>>
>> hm, what does all this stuff in the selftest makefile do?
>>
>> The selftests code has undergone some changes since you last looked.
>
>Hmm, thanks for pointing.
>
>> 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.
>>
>
>make V=1 will show the command line, I tried to make the output to look
>the same as in case of building kernel.
>
>>
>> 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/ ...
>> kcmp_test.c: In function 'sys_kcmp':
>> kcmp_test.c:22: error: '__NR_kcmp' undeclared (first use in this
>function)
>...
>> How are we supposed to be picking up __NR_kcmp?
>>
>
>Initially I made it to look into arch/x86 directory and find __NR_kcmp
>definition there but then I realised (and someone pointed me as
>well) that headers should be taken from those which are generated
>by kernel, ie the result of 'make headers_install'. So if you run
>make headers_install then the test program should work. If this is
>wrong, I can fix it and make a patch on top.
>
>Ie instead of
>
>+#include <linux/unistd.h>
>
>there will be
>
>+#ifdef CONFIG_X86_64
>+#include <asm/unistd_64.h>
>+#else
>+#include <asm/unistd_32.h>
>+#endif
>
> Cyrill
--
Sent from my Android phone with K-9 Mail. Please excuse my brevity.
On Tue, Feb 14, 2012 at 10:55:55PM -0800, [email protected] wrote:
>
> What? <linux/unistd.h> should be used, and it should handle
> the inclusions.
>
Peter, I maybe missing something which directories I should
add to -I option, letme recheck (but without headers_intall
target the syscall number is unresolved for me).
Cyrill
On Wed, Feb 15, 2012 at 11:04:27AM +0400, Cyrill Gorcunov wrote:
> On Tue, Feb 14, 2012 at 10:55:55PM -0800, [email protected] wrote:
> >
> > What? <linux/unistd.h> should be used, and it should handle
> > the inclusions.
> >
>
> Peter, I maybe missing something which directories I should
> add to -I option, letme recheck (but without headers_intall
> target the syscall number is unresolved for me).
>
Ah, I missed to add
+CFLAGS += -I../../../../arch/x86/include/
into Makefile. Andrew, should I send update as a separate
patch?
Cyrill
On Wed, 15 Feb 2012 11:24:54 +0400
Cyrill Gorcunov <[email protected]> wrote:
> On Wed, Feb 15, 2012 at 11:04:27AM +0400, Cyrill Gorcunov wrote:
> > On Tue, Feb 14, 2012 at 10:55:55PM -0800, [email protected] wrote:
> > >
> > > What? <linux/unistd.h> should be used, and it should handle
> > > the inclusions.
> > >
> >
> > Peter, I maybe missing something which directories I should
> > add to -I option, letme recheck (but without headers_intall
> > target the syscall number is unresolved for me).
> >
>
> Ah, I missed to add
>
> +CFLAGS += -I../../../../arch/x86/include/
>
> into Makefile. Andrew, should I send update as a separate
> patch?
>
That worked.
What's with all those warnings, btw?
From: Andrew Morton <[email protected]>
Subject: syscalls-x86-add-__nr_kcmp-syscall-v8-fix-fix-fix
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'
Cc: "Eric W. Biederman" <[email protected]>
Cc: Cyrill Gorcunov <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---
tools/testing/selftests/kcmp/kcmp_test.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/tools/testing/selftests/kcmp/kcmp_test.c~syscalls-x86-add-__nr_kcmp-syscall-v8-fix-fix-fix
+++ a/tools/testing/selftests/kcmp/kcmp_test.c
@@ -54,8 +54,9 @@ int main(int argc, char **argv)
}
/* An example of output and arguments */
- printf("pid1: %6d pid2: %6d FD: %2d FILES: %2d VM: %2d FS: %2d "
- "SIGHAND: %2d IO: %2d SYSVSEM: %2d INV: %2d\n",
+ printf("pid1: %6d pid2: %6d FD: %2ld FILES: %2ld VM: %2ld "
+ "FS: %2ld SIGHAND: %2ld IO: %2ld SYSVSEM: %2ld "
+ "INV: %2ld\n",
pid1, pid2,
sys_kcmp(pid1, pid2, KCMP_FILE, fd1, fd2),
sys_kcmp(pid1, pid2, KCMP_FILES, 0, 0),
_
On Wed, Feb 15, 2012 at 01:53:13PM -0800, Andrew Morton wrote:
> That worked.
>
> What's with all those warnings, btw?
>
> From: Andrew Morton <[email protected]>
> Subject: syscalls-x86-add-__nr_kcmp-syscall-v8-fix-fix-fix
>
> kcmp_test.c: In function 'main':
> kcmp_test.c:69: warning: format '%2d' expects type 'int', but argument 4 has type 'long int'
Indeed it's nit, wonder why I've not beed warned by compiler before
(nothing serious since results do fit integer anyway but _must_
be fixed). I'll update shortly. Sorry for that.
Cyrill
On Thu, Feb 16, 2012 at 02:00:40AM +0400, Cyrill Gorcunov wrote:
> On Wed, Feb 15, 2012 at 01:53:13PM -0800, Andrew Morton wrote:
> > That worked.
> >
> > What's with all those warnings, btw?
> >
> > From: Andrew Morton <[email protected]>
> > Subject: syscalls-x86-add-__nr_kcmp-syscall-v8-fix-fix-fix
> >
> > kcmp_test.c: In function 'main':
> > kcmp_test.c:69: warning: format '%2d' expects type 'int', but argument 4 has type 'long int'
>
> Indeed it's nit, wonder why I've not beed warned by compiler before
> (nothing serious since results do fit integer anyway but _must_
> be fixed). I'll update shortly. Sorry for that.
>
Heh, I just realized that you've fixed it already. Thanks a lot!
Cyrill