linux-kernel - [PATCH v3 08/29] mm: Define VM_SHADOW

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: <20240403234054.2020347-9-debug@rivosinc.com>
Date: Wed,  3 Apr 2024 16:34:56 -0700
From: Deepak Gupta <debug@...osinc.com>
To: paul.walmsley@...ive.com,
	rick.p.edgecombe@...el.com,
	broonie@...nel.org,
	Szabolcs.Nagy@....com,
	kito.cheng@...ive.com,
	keescook@...omium.org,
	ajones@...tanamicro.com,
	conor.dooley@...rochip.com,
	cleger@...osinc.com,
	atishp@...shpatra.org,
	alex@...ti.fr,
	bjorn@...osinc.com,
	alexghiti@...osinc.com,
	samuel.holland@...ive.com,
	conor@...nel.org
Cc: linux-doc@...r.kernel.org,
	linux-riscv@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	devicetree@...r.kernel.org,
	linux-mm@...ck.org,
	linux-arch@...r.kernel.org,
	linux-kselftest@...r.kernel.org,
	corbet@....net,
	palmer@...belt.com,
	aou@...s.berkeley.edu,
	robh+dt@...nel.org,
	krzysztof.kozlowski+dt@...aro.org,
	oleg@...hat.com,
	akpm@...ux-foundation.org,
	arnd@...db.de,
	ebiederm@...ssion.com,
	Liam.Howlett@...cle.com,
	vbabka@...e.cz,
	lstoakes@...il.com,
	shuah@...nel.org,
	brauner@...nel.org,
	debug@...osinc.com,
	andy.chiu@...ive.com,
	jerry.shih@...ive.com,
	hankuan.chen@...ive.com,
	greentime.hu@...ive.com,
	evan@...osinc.com,
	xiao.w.wang@...el.com,
	charlie@...osinc.com,
	apatel@...tanamicro.com,
	mchitale@...tanamicro.com,
	dbarboza@...tanamicro.com,
	sameo@...osinc.com,
	shikemeng@...weicloud.com,
	willy@...radead.org,
	vincent.chen@...ive.com,
	guoren@...nel.org,
	samitolvanen@...gle.com,
	songshuaishuai@...ylab.org,
	gerg@...nel.org,
	heiko@...ech.de,
	bhe@...hat.com,
	jeeheng.sia@...rfivetech.com,
	cyy@...self.name,
	maskray@...gle.com,
	ancientmodern4@...il.com,
	mathis.salmen@...sal.de,
	cuiyunhui@...edance.com,
	bgray@...ux.ibm.com,
	mpe@...erman.id.au,
	baruch@...s.co.il,
	alx@...nel.org,
	david@...hat.com,
	catalin.marinas@....com,
	revest@...omium.org,
	josh@...htriplett.org,
	shr@...kernel.io,
	deller@....de,
	omosnace@...hat.com,
	ojeda@...nel.org,
	jhubbard@...dia.com
Subject: [PATCH v3 08/29] mm: Define VM_SHADOW_STACK for RISC-V

VM_SHADOW_STACK is defined by x86 as vm flag to mark a shadow stack vma.

x86 uses VM_HIGH_ARCH_5 bit but that limits shadow stack vma to 64bit only.
arm64 follows same path (see links)

To keep things simple, RISC-V follows the same.
This patch adds `ss` for shadow stack in process maps.

Links:
https://lore.kernel.org/lkml/20231009-arm64-gcs-v6-12-78e55deaa4dd@kernel.org/#r

Signed-off-by: Deepak Gupta <debug@...osinc.com>
---
 fs/proc/task_mmu.c |  3 +++
 include/linux/mm.h | 11 ++++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 3f78ebbb795f..d9d63eb74f0d 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -702,6 +702,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
 #ifdef CONFIG_X86_USER_SHADOW_STACK
 		[ilog2(VM_SHADOW_STACK)] = "ss",
+#endif
+#ifdef CONFIG_RISCV_USER_CFI
+		[ilog2(VM_SHADOW_STACK)] = "ss",
 #endif
 	};
 	size_t i;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index f5a97dec5169..64109f6c70f5 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -352,7 +352,16 @@ extern unsigned int kobjsize(const void *objp);
  * for more details on the guard size.
  */
 # define VM_SHADOW_STACK	VM_HIGH_ARCH_5
-#else
+#endif
+
+#ifdef CONFIG_RISCV_USER_CFI
+/*
+ * RISC-V is going along with using VM_HIGH_ARCH_5 bit position for shadow stack
+ */
+#define VM_SHADOW_STACK	VM_HIGH_ARCH_5
+#endif
+
+#ifndef VM_SHADOW_STACK
 # define VM_SHADOW_STACK	VM_NONE
 #endif
 
-- 
2.43.2