linux-kernel - [PATCH v6 07/12] mm/mempolicy: allow home_node to be set by mpol

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20240103224209.2541-8-gregory.price@memverge.com>
Date: Wed,  3 Jan 2024 17:42:04 -0500
From: Gregory Price <gourry.memverge@...il.com>
To: linux-mm@...ck.org
Cc: linux-doc@...r.kernel.org,
	linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-api@...r.kernel.org,
	linux-arch@...r.kernel.org,
	akpm@...ux-foundation.org,
	arnd@...db.de,
	tglx@...utronix.de,
	luto@...nel.org,
	mingo@...hat.com,
	bp@...en8.de,
	dave.hansen@...ux.intel.com,
	hpa@...or.com,
	mhocko@...nel.org,
	tj@...nel.org,
	ying.huang@...el.com,
	gregory.price@...verge.com,
	corbet@....net,
	rakie.kim@...com,
	hyeongtak.ji@...com,
	honggyu.kim@...com,
	vtavarespetr@...ron.com,
	peterz@...radead.org,
	jgroves@...ron.com,
	ravis.opensrc@...ron.com,
	sthanneeru@...ron.com,
	emirakhur@...ron.com,
	Hasan.Maruf@....com,
	seungjun.ha@...sung.com
Subject: [PATCH v6 07/12] mm/mempolicy: allow home_node to be set by mpol_new

This patch adds the plumbing into mpol_new() to allow the argument
structure's home_node field to be set during mempolicy creation.

The syscall sys_set_mempolicy_home_node was added to allow a home
node to be registered for a vma.

For set_mempolicy2 and mbind2 syscalls, it would be useful to add
this as an extension to allow the user to submit a fully formed
mempolicy configuration in a single call, rather than require
multiple calls to configure a mempolicy.

This will become particularly useful if/when pidfd interfaces to
change process mempolicies from outside the task appear, as each
call to change the mempolicy does an atomic swap of that policy
in the task, rather than mutate the policy.

Signed-off-by: Gregory Price <gregory.price@...verge.com>
---
 mm/mempolicy.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index db290cf540d7..4a566341cf43 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -321,7 +321,7 @@ static struct mempolicy *mpol_new(struct mempolicy_param *param)
 	atomic_set(&policy->refcnt, 1);
 	policy->mode = mode;
 	policy->flags = flags;
-	policy->home_node = NUMA_NO_NODE;
+	policy->home_node = param->home_node;
 	policy->wil.cur_weight = 0;
 
 	return policy;
@@ -1634,6 +1634,7 @@ static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask,
 	param.mode = lmode;
 	param.mode_flags = mode_flags;
 	param.policy_nodes = &nodes;
+	param.home_node = NUMA_NO_NODE;
 
 	return do_set_mempolicy(&param);
 }
@@ -3002,6 +3003,8 @@ void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
 		mparam.mode = mpol->mode;
 		mparam.mode_flags = mpol->flags;
 		mparam.policy_nodes = &mpol->w.user_nodemask;
+		mparam.home_node = NUMA_NO_NODE;
+
 		/* contextualize the tmpfs mount point mempolicy to this file */
 		npol = mpol_new(&mparam);
 		if (IS_ERR(npol))
@@ -3160,6 +3163,7 @@ void __init numa_policy_init(void)
 	memset(&param, 0, sizeof(param));
 	param.mode = MPOL_INTERLEAVE;
 	param.policy_nodes = &interleave_nodes;
+	param.home_node = NUMA_NO_NODE;
 
 	if (do_set_mempolicy(&param))
 		pr_err("%s: interleaving failed\n", __func__);
@@ -3174,6 +3178,7 @@ void numa_default_policy(void)
 
 	memset(&param, 0, sizeof(param));
 	param.mode = MPOL_DEFAULT;
+	param.home_node = NUMA_NO_NODE;
 
 	do_set_mempolicy(&param);
 }
@@ -3296,6 +3301,8 @@ int mpol_parse_str(char *str, struct mempolicy **mpol)
 	mparam.mode = mode;
 	mparam.mode_flags = mode_flags;
 	mparam.policy_nodes = &nodes;
+	mparam.home_node = NUMA_NO_NODE;
+
 	new = mpol_new(&mparam);
 	if (IS_ERR(new))
 		goto out;
-- 
2.39.1