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From: Sandipan Das <sandipan@linux.ibm.com>
To: shuah@kernel.org, linux-kselftest@vger.kernel.org
Cc: linux-arch@vger.kernel.org, fweimer@redhat.com,
	dave.hansen@intel.com, x86@kernel.org, linuxram@us.ibm.com,
	mhocko@kernel.org, linux-mm@kvack.org, mingo@redhat.com,
	aneesh.kumar@linux.ibm.com, bauerman@linux.ibm.com,
	msuchanek@suse.de, mpe@ellerman.id.au,
	linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v16 07/23] selftests: vm: pkeys: Add helpers for pkey bits
Date: Fri, 17 Jan 2020 18:19:46 +0530
Message-ID: <899542624ac1245640966a537599bf9b86077c47.1579265066.git.sandipan@linux.ibm.com> (raw)
In-Reply-To: <cover.1579265066.git.sandipan@linux.ibm.com>
In-Reply-To: <cover.1579265066.git.sandipan@linux.ibm.com>

This introduces some functions that help with setting
or clearing bits of a particular pkey. This also adds
an abstraction for getting a pkey's bit position in
the pkey register as this may vary across architectures.

cc: Dave Hansen <dave.hansen@intel.com>
cc: Florian Weimer <fweimer@redhat.com>
cc: Ram Pai <linuxram@us.ibm.com>
cc: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
---
 tools/testing/selftests/vm/pkey-helpers.h    | 22 ++++++++++++++
 tools/testing/selftests/vm/pkey-x86.h        |  5 +++
 tools/testing/selftests/vm/protection_keys.c | 32 ++++++--------------
 3 files changed, 36 insertions(+), 23 deletions(-)

diff --git a/tools/testing/selftests/vm/pkey-helpers.h b/tools/testing/selftests/vm/pkey-helpers.h
index cc3491a6df2d..df4b46050393 100644
--- a/tools/testing/selftests/vm/pkey-helpers.h
+++ b/tools/testing/selftests/vm/pkey-helpers.h
@@ -80,6 +80,28 @@ extern void abort_hooks(void);
 #error Architecture not supported
 #endif /* arch */
 
+#define PKEY_MASK	(PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE)
+
+static inline u64 set_pkey_bits(u64 reg, int pkey, u64 flags)
+{
+	u32 shift = pkey_bit_position(pkey);
+	/* mask out bits from pkey in old value */
+	reg &= ~((u64)PKEY_MASK << shift);
+	/* OR in new bits for pkey */
+	reg |= (flags & PKEY_MASK) << shift;
+	return reg;
+}
+
+static inline u64 get_pkey_bits(u64 reg, int pkey)
+{
+	u32 shift = pkey_bit_position(pkey);
+	/*
+	 * shift down the relevant bits to the lowest two, then
+	 * mask off all the other higher bits
+	 */
+	return ((reg >> shift) & PKEY_MASK);
+}
+
 extern u64 shadow_pkey_reg;
 
 static inline u64 _read_pkey_reg(int line)
diff --git a/tools/testing/selftests/vm/pkey-x86.h b/tools/testing/selftests/vm/pkey-x86.h
index dc34ae21e714..f05e45ecaffb 100644
--- a/tools/testing/selftests/vm/pkey-x86.h
+++ b/tools/testing/selftests/vm/pkey-x86.h
@@ -118,6 +118,11 @@ static inline int cpu_has_pku(void)
 	return 1;
 }
 
+static inline u32 pkey_bit_position(int pkey)
+{
+	return pkey * PKEY_BITS_PER_PKEY;
+}
+
 #define XSTATE_PKEY_BIT	(9)
 #define XSTATE_PKEY	0x200
 
diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index f36e9e7789ce..3ce5a87804ab 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -333,25 +333,13 @@ pid_t fork_lazy_child(void)
 
 static u32 hw_pkey_get(int pkey, unsigned long flags)
 {
-	u32 mask = (PKEY_DISABLE_ACCESS|PKEY_DISABLE_WRITE);
 	u64 pkey_reg = __read_pkey_reg();
-	u64 shifted_pkey_reg;
-	u32 masked_pkey_reg;
 
 	dprintf1("%s(pkey=%d, flags=%lx) = %x / %d\n",
 			__func__, pkey, flags, 0, 0);
 	dprintf2("%s() raw pkey_reg: %016lx\n", __func__, pkey_reg);
 
-	shifted_pkey_reg = (pkey_reg >> (pkey * PKEY_BITS_PER_PKEY));
-	dprintf2("%s() shifted_pkey_reg: %016lx\n", __func__,
-			shifted_pkey_reg);
-	masked_pkey_reg = shifted_pkey_reg & mask;
-	dprintf2("%s() masked  pkey_reg: %x\n", __func__, masked_pkey_reg);
-	/*
-	 * shift down the relevant bits to the lowest two, then
-	 * mask off all the other high bits.
-	 */
-	return masked_pkey_reg;
+	return (u32) get_pkey_bits(pkey_reg, pkey);
 }
 
 static int hw_pkey_set(int pkey, unsigned long rights, unsigned long flags)
@@ -363,12 +351,8 @@ static int hw_pkey_set(int pkey, unsigned long rights, unsigned long flags)
 	/* make sure that 'rights' only contains the bits we expect: */
 	assert(!(rights & ~mask));
 
-	/* copy old pkey_reg */
-	new_pkey_reg = old_pkey_reg;
-	/* mask out bits from pkey in old value: */
-	new_pkey_reg &= ~(mask << (pkey * PKEY_BITS_PER_PKEY));
-	/* OR in new bits for pkey: */
-	new_pkey_reg |= (rights << (pkey * PKEY_BITS_PER_PKEY));
+	/* modify bits accordingly in old pkey_reg and assign it */
+	new_pkey_reg = set_pkey_bits(old_pkey_reg, pkey, rights);
 
 	__write_pkey_reg(new_pkey_reg);
 
@@ -402,7 +386,7 @@ void pkey_disable_set(int pkey, int flags)
 	ret = hw_pkey_set(pkey, pkey_rights, syscall_flags);
 	assert(!ret);
 	/* pkey_reg and flags have the same format */
-	shadow_pkey_reg |= flags << (pkey * 2);
+	shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, pkey, pkey_rights);
 	dprintf1("%s(%d) shadow: 0x%016lx\n",
 		__func__, pkey, shadow_pkey_reg);
 
@@ -436,7 +420,7 @@ void pkey_disable_clear(int pkey, int flags)
 	pkey_rights |= flags;
 
 	ret = hw_pkey_set(pkey, pkey_rights, 0);
-	shadow_pkey_reg &= ~(flags << (pkey * 2));
+	shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, pkey, pkey_rights);
 	pkey_assert(ret >= 0);
 
 	pkey_rights = hw_pkey_get(pkey, syscall_flags);
@@ -512,7 +496,8 @@ int alloc_pkey(void)
 			shadow_pkey_reg);
 	if (ret) {
 		/* clear both the bits: */
-		shadow_pkey_reg &= ~(0x3      << (ret * 2));
+		shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, ret,
+						~PKEY_MASK);
 		dprintf4("%s()::%d, ret: %d pkey_reg: 0x%016lx"
 				" shadow: 0x%016lx\n",
 				__func__,
@@ -522,7 +507,8 @@ int alloc_pkey(void)
 		 * move the new state in from init_val
 		 * (remember, we cheated and init_val == pkey_reg format)
 		 */
-		shadow_pkey_reg |=  (init_val << (ret * 2));
+		shadow_pkey_reg = set_pkey_bits(shadow_pkey_reg, ret,
+						init_val);
 	}
 	dprintf4("%s()::%d, ret: %d pkey_reg: 0x%016lx"
 			" shadow: 0x%016lx\n",
-- 
2.17.1


  parent reply index

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-17 12:49 [PATCH v16 00/23] selftests, powerpc, x86: Memory Protection Keys Sandipan Das
2020-01-17 12:49 ` [PATCH v16 01/23] selftests/x86/pkeys: Move selftests to arch-neutral directory Sandipan Das
2020-01-17 12:49 ` [PATCH v16 02/23] selftests/vm: Rename all references to pkru to a generic name Sandipan Das
2020-01-17 12:49 ` [PATCH v16 03/23] selftests/vm: Move generic definitions to header file Sandipan Das
2020-01-17 12:49 ` [PATCH v16 04/23] selftests/vm: Move some definitions to arch-specific header Sandipan Das
2020-01-17 12:49 ` [PATCH v16 05/23] selftests/vm: Make gcc check arguments of sigsafe_printf() Sandipan Das
2020-01-17 12:49 ` [PATCH v16 06/23] selftests/vm: Typecast references to pkey register Sandipan Das
2020-01-17 12:49 ` Sandipan Das [this message]
2020-01-17 12:49 ` [PATCH v16 08/23] selftests/vm: Fix pkey_disable_clear() Sandipan Das
2020-01-17 12:49 ` [PATCH v16 09/23] selftests/vm/pkeys: Fix assertion in pkey_disable_set/clear() Sandipan Das
2020-01-17 12:49 ` [PATCH v16 10/23] selftests/vm/pkeys: Fix alloc_random_pkey() to make it really random Sandipan Das
2020-01-17 12:49 ` [PATCH v16 11/23] selftests: vm: pkeys: Use the correct huge page size Sandipan Das
2020-01-17 12:49 ` [PATCH v16 12/23] selftests/vm/pkeys: Introduce generic pkey abstractions Sandipan Das
2020-01-17 12:49 ` [PATCH v16 13/23] selftests/vm/pkeys: Introduce powerpc support Sandipan Das
2020-01-17 12:49 ` [PATCH v16 14/23] selftests/vm/pkeys: Fix number of reserved powerpc pkeys Sandipan Das
2020-01-17 12:49 ` [PATCH v16 15/23] selftests/vm/pkeys: Fix assertion in test_pkey_alloc_exhaust() Sandipan Das
2020-01-17 12:49 ` [PATCH v16 16/23] selftests/vm/pkeys: Improve checks to determine pkey support Sandipan Das
2020-01-17 12:49 ` [PATCH v16 17/23] selftests/vm/pkeys: Associate key on a mapped page and detect access violation Sandipan Das
2020-01-17 12:49 ` [PATCH v16 18/23] selftests/vm/pkeys: Associate key on a mapped page and detect write violation Sandipan Das
2020-01-17 12:49 ` [PATCH v16 19/23] selftests/vm/pkeys: Detect write violation on a mapped access-denied-key page Sandipan Das
2020-01-17 12:49 ` [PATCH v16 20/23] selftests/vm/pkeys: Introduce a sub-page allocator Sandipan Das
2020-01-17 12:50 ` [PATCH v16 21/23] selftests/vm/pkeys: Test correct behaviour of pkey-0 Sandipan Das
2020-01-17 12:50 ` [PATCH v16 22/23] selftests/vm/pkeys: Override access right definitions on powerpc Sandipan Das
2020-01-17 12:50 ` [PATCH v16 23/23] selftests: vm: pkeys: Use the correct page size " Sandipan Das
2020-01-17 18:02 ` [PATCH v16 00/23] selftests, powerpc, x86: Memory Protection Keys Dave Hansen
2020-01-18  9:24   ` Sandipan Das

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