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From: "Christopher M. Riedl" <cmr@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: tglx@linutronix.de, x86@kernel.org,
	linux-hardening@vger.kernel.org, keescook@chromium.org
Subject: [RESEND PATCH v4 09/11] lkdtm/powerpc: Fix code patching hijack test
Date: Wed,  5 May 2021 23:34:50 -0500	[thread overview]
Message-ID: <20210506043452.9674-10-cmr@linux.ibm.com> (raw)
In-Reply-To: <20210506043452.9674-1-cmr@linux.ibm.com>

Code patching on powerpc with a STRICT_KERNEL_RWX uses a userspace
address in a temporary mm now. Use __put_user() to avoid write failures
due to KUAP when attempting a "hijack" on the patching address.

Signed-off-by: Christopher M. Riedl <cmr@linux.ibm.com>
---
 drivers/misc/lkdtm/perms.c | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c
index 55c3bec6d3b72..af9bf285fe326 100644
--- a/drivers/misc/lkdtm/perms.c
+++ b/drivers/misc/lkdtm/perms.c
@@ -268,16 +268,7 @@ static inline u32 lkdtm_read_patch_site(void)
 /* Returns True if the write succeeds */
 static inline bool lkdtm_try_write(u32 data, u32 *addr)
 {
-#ifdef CONFIG_PPC
-	__put_kernel_nofault(addr, &data, u32, err);
-	return true;
-
-err:
-	return false;
-#endif
-#ifdef CONFIG_X86_64
 	return !__put_user(data, addr);
-#endif
 }
 
 static int lkdtm_patching_cpu(void *data)
-- 
2.26.1


  parent reply	other threads:[~2021-05-06  4:37 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-06  4:34 [RESEND PATCH v4 00/11] Use per-CPU temporary mappings for patching Christopher M. Riedl
2021-05-06  4:34 ` [RESEND PATCH v4 01/11] powerpc: Add LKDTM accessor for patching addr Christopher M. Riedl
2021-05-06  4:34 ` [RESEND PATCH v4 02/11] lkdtm/powerpc: Add test to hijack a patch mapping Christopher M. Riedl
2021-05-06  4:34 ` [RESEND PATCH v4 03/11] x86_64: Add LKDTM accessor for patching addr Christopher M. Riedl
2021-05-06  4:34 ` [RESEND PATCH v4 04/11] lkdtm/x86_64: Add test to hijack a patch mapping Christopher M. Riedl
2021-05-06  4:34 ` [RESEND PATCH v4 05/11] powerpc/64s: Add ability to skip SLB preload Christopher M. Riedl
2021-06-21  3:13   ` Daniel Axtens
2021-07-01  3:48     ` Christopher M. Riedl
2021-07-01  4:15       ` Nicholas Piggin
2021-07-01  5:28         ` Christopher M. Riedl
2021-07-01  6:04           ` Nicholas Piggin
2021-07-01  6:53             ` Christopher M. Riedl
2021-07-01  7:37               ` Nicholas Piggin
2021-07-01 11:30                 ` Nicholas Piggin
2021-07-09  4:55                 ` Christopher M. Riedl
2021-05-06  4:34 ` [RESEND PATCH v4 06/11] powerpc: Introduce temporary mm Christopher M. Riedl
2021-05-06  4:34 ` [RESEND PATCH v4 07/11] powerpc/64s: Make slb_allocate_user() non-static Christopher M. Riedl
2021-05-06  4:34 ` [RESEND PATCH v4 08/11] powerpc: Initialize and use a temporary mm for patching Christopher M. Riedl
2021-06-21  3:19   ` Daniel Axtens
2021-07-01  5:11     ` Christopher M. Riedl
2021-07-01  6:12   ` Nicholas Piggin
2021-07-01  7:02     ` Christopher M. Riedl
2021-07-01  7:51       ` Nicholas Piggin
2021-07-09  5:03         ` Christopher M. Riedl
2021-05-06  4:34 ` Christopher M. Riedl [this message]
2021-05-06  4:34 ` [RESEND PATCH v4 10/11] powerpc: Protect patching_mm with a lock Christopher M. Riedl
2021-05-06 10:51   ` Peter Zijlstra
2021-05-07 20:03     ` Christopher M. Riedl
2021-05-07 22:26       ` Peter Zijlstra
2021-05-06  4:34 ` [RESEND PATCH v4 11/11] powerpc: Use patch_instruction_unlocked() in loops Christopher M. Riedl

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