The patch titled
Subject: syscalls-x86-add-__nr_kcmp-syscall-v8 comment update
has been added to the -mm tree. Its filename is
syscalls-x86-add-__nr_kcmp-syscall-v8-comment-update.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
Subject: syscalls-x86-add-__nr_kcmp-syscall-v8 comment update
Signed-off-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/kcmp.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff -puN kernel/kcmp.c~syscalls-x86-add-__nr_kcmp-syscall-v8-comment-update kernel/kcmp.c
--- a/kernel/kcmp.c~syscalls-x86-add-__nr_kcmp-syscall-v8-comment-update
+++ a/kernel/kcmp.c
@@ -18,6 +18,17 @@
* reasons, still the comparison results should be suitable for
* sorting. Thus, we obfuscate kernel pointers values and compare
* the production instead.
+ *
+ * The obfuscation is done in two steps. First -- we use xor on
+ * kernel pointer with random value, which puts pointer into
+ * a new position in reordered space. Second -- we multiply
+ * the xor production with big odd random number to permute
+ * bits even more (the odd multiplier guarantees that the product
+ * is unique ever after the high bits are truncated, since any odd
+ * number is relative prime to 2^n).
+ *
+ * Note also the obfuscation itself is invisible to user-space
+ * and if needed it can be changed to any suitable scheme.
*/
static unsigned long cookies[KCMP_TYPES][2] __read_mostly;
_
Subject: Subject: syscalls-x86-add-__nr_kcmp-syscall-v8 comment update
Patches currently in -mm which might be from gorcunov@xxxxxxxxxx are
linux-next.patch
sysctl-make-kernelns_last_pid-control-being-checkpoint_restore-dependent.patch
fs-proc-introduce-proc-pid-task-tid-children-entry-v9.patch
syscalls-x86-add-__nr_kcmp-syscall-v8.patch
syscalls-x86-add-__nr_kcmp-syscall-v8-comment-update.patch
syscalls-x86-add-__nr_kcmp-syscall-v8-comment-update-fix.patch
c-r-procfs-add-arg_start-end-env_start-end-and-exit_code-members-to-proc-pid-stat.patch
c-r-prctl-extend-pr_set_mm-to-set-up-more-mm_struct-entries-v2.patch
c-r-prctl-add-ability-to-set-new-mm_struct-exe_file.patch
c-r-prctl-add-ability-to-get-clear_tid_address.patch
c-r-ipc-message-queue-receive-cleanup.patch
c-r-ipc-message-queue-stealing-feature-introduced.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
