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Message-Id: <20181221181423.20455-5-igor.stoppa@huawei.com>
Date: Fri, 21 Dec 2018 20:14:15 +0200
From: Igor Stoppa <igor.stoppa@...il.com>
To: Andy Lutomirski <luto@...capital.net>,
Matthew Wilcox <willy@...radead.org>,
Peter Zijlstra <peterz@...radead.org>,
Dave Hansen <dave.hansen@...ux.intel.com>,
Mimi Zohar <zohar@...ux.vnet.ibm.com>,
Thiago Jung Bauermann <bauerman@...ux.ibm.com>
Cc: igor.stoppa@...wei.com,
Nadav Amit <nadav.amit@...il.com>,
Kees Cook <keescook@...omium.org>,
Ahmed Soliman <ahmedsoliman@...a.vt.edu>,
linux-integrity@...r.kernel.org,
kernel-hardening@...ts.openwall.com,
linux-mm@...ck.org,
linux-kernel@...r.kernel.org
Subject: [PATCH 04/12] __wr_after_init: debug writes
After each write operation, confirm that it was successful, otherwise
generate a warning.
Signed-off-by: Igor Stoppa <igor.stoppa@...wei.com>
CC: Andy Lutomirski <luto@...capital.net>
CC: Nadav Amit <nadav.amit@...il.com>
CC: Matthew Wilcox <willy@...radead.org>
CC: Peter Zijlstra <peterz@...radead.org>
CC: Kees Cook <keescook@...omium.org>
CC: Dave Hansen <dave.hansen@...ux.intel.com>
CC: Mimi Zohar <zohar@...ux.vnet.ibm.com>
CC: Thiago Jung Bauermann <bauerman@...ux.ibm.com>
CC: Ahmed Soliman <ahmedsoliman@...a.vt.edu>
CC: linux-integrity@...r.kernel.org
CC: kernel-hardening@...ts.openwall.com
CC: linux-mm@...ck.org
CC: linux-kernel@...r.kernel.org
---
mm/Kconfig.debug | 8 ++++++++
mm/prmem.c | 6 ++++++
2 files changed, 14 insertions(+)
diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
index 9a7b8b049d04..b10305cfac3c 100644
--- a/mm/Kconfig.debug
+++ b/mm/Kconfig.debug
@@ -94,3 +94,11 @@ config DEBUG_RODATA_TEST
depends on STRICT_KERNEL_RWX
---help---
This option enables a testcase for the setting rodata read-only.
+
+config DEBUG_PRMEM
+ bool "Verify each write rare operation."
+ depends on PRMEM
+ default n
+ help
+ After any write rare operation, compares the data written with the
+ value provided by the caller.
diff --git a/mm/prmem.c b/mm/prmem.c
index e1c1be3a1171..51f6776e2515 100644
--- a/mm/prmem.c
+++ b/mm/prmem.c
@@ -61,6 +61,9 @@ void *wr_memcpy(void *p, const void *q, __kernel_size_t size)
__wr_enable(&wr_state);
__wr_memcpy(wr_poking_addr, q, size);
__wr_disable(&wr_state);
+#ifdef CONFIG_DEBUG_PRMEM
+ VM_WARN_ONCE(memcmp(p, q, size), "Failed %s()", __func__);
+#endif
local_irq_enable();
return p;
}
@@ -92,6 +95,9 @@ void *wr_memset(void *p, int c, __kernel_size_t len)
__wr_enable(&wr_state);
__wr_memset(wr_poking_addr, c, len);
__wr_disable(&wr_state);
+#ifdef CONFIG_DEBUG_PRMEM
+ VM_WARN_ONCE(memtst(p, c, len), "Failed %s()", __func__);
+#endif
local_irq_enable();
return p;
}
--
2.19.1
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