Messages in this thread Patch in this message | | | Date | Tue, 1 Nov 2005 09:39:35 -0800 (PST) | From | Christoph Lameter <> | Subject | Re: [PATCH 5/5] Swap Migration V5: sys_migrate_pages interface |
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On Mon, 31 Oct 2005, Andrew Morton wrote:
> Christoph Lameter <clameter@sgi.com> wrote: > > + * Permissions check like for signals. > > + * See check_kill_permission() > Obscure. Can you please explain the thinking behind putting this check in > here? Preferably via a comment... >
Index: linux-2.6.14-rc5-mm1/mm/mempolicy.c =================================================================== --- linux-2.6.14-rc5-mm1.orig/mm/mempolicy.c 2005-11-01 09:32:46.000000000 -0800 +++ linux-2.6.14-rc5-mm1/mm/mempolicy.c 2005-11-01 09:38:46.000000000 -0800 @@ -790,8 +790,15 @@ asmlinkage long sys_migrate_pages(pid_t return -EINVAL; /* - * Permissions check like for signals. - * See check_kill_permission() + * We only allow a process to move the pages of another + * if the process issuing sys_migrate has the right to send a kill + * signal to the process to be moved. Moving another processes + * memory may impact the performance of that process. If the + * process issuing sys_migrate_pages has the right to kill the + * target process then obviously that process has the right to + * impact the performance of the target process. + * + * The permission check was taken from check_kill_permission() */ if ((current->euid ^ task->suid) && (current->euid ^ task->uid) && (current->uid ^ task->suid) && (current->uid ^ task->uid) && - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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