linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org, mpe@ellerman.id.au
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Subject: [PATCH v5 16/23] powerpc/book3s64/kuap: Restrict access to userspace based on userspace AMR
Date: Thu, 27 Aug 2020 09:39:24 +0530	[thread overview]
Message-ID: <20200827040931.297759-17-aneesh.kumar@linux.ibm.com> (raw)
In-Reply-To: <20200827040931.297759-1-aneesh.kumar@linux.ibm.com>

If an application has configured address protection such that read/write is
denied using pkey even the kernel should receive a FAULT on accessing the same.

This patch use user AMR value stored in pt_regs.kuap to achieve the same.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/include/asm/book3s/64/kup.h | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 4e1d666032f6..878cd84922d8 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -292,14 +292,20 @@ static inline void set_kuap(unsigned long value)
 static __always_inline void allow_user_access(void __user *to, const void __user *from,
 					      unsigned long size, unsigned long dir)
 {
+	unsigned long thread_amr = 0;
+
 	// This is written so we can resolve to a single case at build time
 	BUILD_BUG_ON(!__builtin_constant_p(dir));
+
+	if (mmu_has_feature(MMU_FTR_PKEY))
+		thread_amr = current_thread_amr();
+
 	if (dir == KUAP_READ)
-		set_kuap(AMR_KUAP_BLOCK_WRITE);
+		set_kuap(thread_amr | AMR_KUAP_BLOCK_WRITE);
 	else if (dir == KUAP_WRITE)
-		set_kuap(AMR_KUAP_BLOCK_READ);
+		set_kuap(thread_amr | AMR_KUAP_BLOCK_READ);
 	else if (dir == KUAP_READ_WRITE)
-		set_kuap(0);
+		set_kuap(thread_amr);
 	else
 		BUILD_BUG();
 }
-- 
2.26.2


  parent reply	other threads:[~2020-08-27  4:42 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-27  4:09 [PATCH v5 00/23] Kernel userspace access/execution prevention with hash translation Aneesh Kumar K.V
2020-08-27  4:09 ` [PATCH v5 01/23] powerpc: Add new macro to handle NESTED_IFCLR Aneesh Kumar K.V
2020-08-27  4:09 ` [PATCH v5 02/23] KVM: PPC: BOOK3S: PR: Ignore UAMOR SPR Aneesh Kumar K.V
2020-08-27  4:09 ` [PATCH v5 03/23] powerpc/book3s64/kuap/kuep: Make KUAP and KUEP a subfeature of PPC_MEM_KEYS Aneesh Kumar K.V
2020-08-27  4:09 ` [PATCH v5 04/23] powerpc/book3s64/kuap/kuep: Move uamor setup to pkey init Aneesh Kumar K.V
2020-08-27  4:09 ` [PATCH v5 05/23] powerpc/book3s64/kuap: Move KUAP related function outside radix Aneesh Kumar K.V
2020-08-27  4:09 ` [PATCH v5 06/23] powerpc/book3s64/kup: Use the correct #ifdef when including headers Aneesh Kumar K.V
2020-08-27  4:09 ` [PATCH v5 07/23] powerpc/book3s64/kuep: Move KUEP related function outside radix Aneesh Kumar K.V
2020-08-27  4:09 ` [PATCH v5 08/23] powerpc/book3s64/kuap: Rename MMU_FTR_RADIX_KUAP to MMU_FTR_KUAP Aneesh Kumar K.V
2020-08-27  4:57   ` Christophe Leroy
2020-08-27  4:09 ` [PATCH v5 09/23] powerpc/book3s64/kuap: Use Key 3 for kernel mapping with hash translation Aneesh Kumar K.V
2020-10-18  3:46   ` Sandipan Das
2020-08-27  4:09 ` [PATCH v5 10/23] powerpc/exec: Set thread.regs early during exec Aneesh Kumar K.V
2020-08-27  4:09 ` [PATCH v5 11/23] powerpc/book3s64/pkeys: Store/restore userspace AMR/IAMR correctly on entry and exit from kernel Aneesh Kumar K.V
2020-10-18  3:49   ` Sandipan Das
2020-08-27  4:09 ` [PATCH v5 12/23] powerpc/book3s64/pkeys: Inherit correctly on fork Aneesh Kumar K.V
2020-10-18  3:50   ` Sandipan Das
2020-08-27  4:09 ` [PATCH v5 13/23] powerpc/book3s64/pkeys: Reset userspace AMR correctly on exec Aneesh Kumar K.V
2020-10-18  3:50   ` Sandipan Das
2020-08-27  4:09 ` [PATCH v5 14/23] powerpc/ptrace-view: Use pt_regs values instead of thread_struct based one Aneesh Kumar K.V
2020-08-27  4:09 ` [PATCH v5 15/23] powerpc/book3s64/pkeys: Don't update SPRN_AMR when in kernel mode Aneesh Kumar K.V
2020-10-18  3:52   ` Sandipan Das
2020-08-27  4:09 ` Aneesh Kumar K.V [this message]
2020-10-18  4:00   ` [PATCH v5 16/23] powerpc/book3s64/kuap: Restrict access to userspace based on userspace AMR Sandipan Das
2020-08-27  4:09 ` [PATCH v5 17/23] powerpc/book3s64/kuap: Improve error reporting with KUAP Aneesh Kumar K.V
2020-08-27  4:09 ` [PATCH v5 18/23] powerpc/book3s64/kuap: Use Key 3 to implement KUAP with hash translation Aneesh Kumar K.V
2020-10-18  4:00   ` Sandipan Das
2020-08-27  4:09 ` [PATCH v5 19/23] powerpc/book3s64/kuep: Use Key 3 to implement KUEP " Aneesh Kumar K.V
2020-10-18  4:01   ` Sandipan Das
2020-08-27  4:09 ` [PATCH v5 20/23] powerpc/book3s64/hash/kuap: Enable kuap on hash Aneesh Kumar K.V
2020-09-12 11:54   ` Michael Ellerman
2020-10-18  4:02   ` Sandipan Das
2020-08-27  4:09 ` [PATCH v5 21/23] powerpc/book3s64/hash/kuep: Enable KUEP " Aneesh Kumar K.V
2020-10-18  4:03   ` Sandipan Das
2020-08-27  4:09 ` [PATCH v5 22/23] powerpc/book3s64/hash/kup: Don't hardcode kup key Aneesh Kumar K.V
2020-08-27  4:09 ` [PATCH v5 23/23] powerpc/book3s64/pkeys: Optimize FTR_KUAP and FTR_KUEP disabled case Aneesh Kumar K.V

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200827040931.297759-17-aneesh.kumar@linux.ibm.com \
    --to=aneesh.kumar@linux.ibm.com \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=mpe@ellerman.id.au \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).