[PATCH AUTOSEL 4.19 1/5] powerpc/selftests: Use timersub() for gettimeofday()

[PATCH AUTOSEL 4.19 1/5] powerpc/selftests: Use timersub() for gettimeofday()

[Sasha Levin]

From: ye xingchen <ye.xingchen@zte.com.cn>

[ Upstream commit c814bf958926ff45a9c1e899bd001006ab6cfbae ]

Use timersub() function to simplify the code.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220816105106.82666-1-ye.xingchen@zte.com.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/powerpc/benchmarks/gettimeofday.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/powerpc/benchmarks/gettimeofday.c b/tools/testing/selftests/powerpc/benchmarks/gettimeofday.c
index 3af3c21e8036..7f4bb84f1c9c 100644
--- a/tools/testing/selftests/powerpc/benchmarks/gettimeofday.c
+++ b/tools/testing/selftests/powerpc/benchmarks/gettimeofday.c
@@ -12,7 +12,7 @@ static int test_gettimeofday(void)
 {
 	int i;
 
-	struct timeval tv_start, tv_end;
+	struct timeval tv_start, tv_end, tv_diff;
 
 	gettimeofday(&tv_start, NULL);
 
@@ -20,7 +20,9 @@ static int test_gettimeofday(void)
 		gettimeofday(&tv_end, NULL);
 	}
 
-	printf("time = %.6f\n", tv_end.tv_sec - tv_start.tv_sec + (tv_end.tv_usec - tv_start.tv_usec) * 1e-6);
+	timersub(&tv_start, &tv_end, &tv_diff);
+
+	printf("time = %.6f\n", tv_diff.tv_sec + (tv_diff.tv_usec) * 1e-6);
 
 	return 0;
 }
-- 
2.35.1

[PATCH AUTOSEL 4.19 2/5] powerpc/85xx: Fix fall-through warning for Clang

[Sasha Levin]

From: "Gustavo A. R. Silva" <gustavoars@kernel.org>

[ Upstream commit d4d944ff68cb1f896d3f3b1af0bc656949dc626a ]

Fix the following fallthrough warning:

arch/powerpc/platforms/85xx/mpc85xx_cds.c:161:3: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/KSPP/linux/issues/198
Link: https://lore.kernel.org/lkml/202209061224.KxORRGVg-lkp@intel.com/
Link: https://lore.kernel.org/r/Yxe8XTY5C9qJLd0Z@work
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/platforms/85xx/mpc85xx_cds.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/platforms/85xx/mpc85xx_cds.c b/arch/powerpc/platforms/85xx/mpc85xx_cds.c
index 224db30c497b..b3736b835c10 100644
--- a/arch/powerpc/platforms/85xx/mpc85xx_cds.c
+++ b/arch/powerpc/platforms/85xx/mpc85xx_cds.c
@@ -162,6 +162,7 @@ static void __init mpc85xx_cds_pci_irq_fixup(struct pci_dev *dev)
 			else
 				dev->irq = 10;
 			pci_write_config_byte(dev, PCI_INTERRUPT_LINE, dev->irq);
+			break;
 		default:
 			break;
 		}
-- 
2.35.1

[PATCH AUTOSEL 4.19 3/5] powerpc: Remove direct call to personality syscall handler

[Sasha Levin]

From: Rohan McLure <rmclure@linux.ibm.com>

[ Upstream commit 4df0221f9ded8c39aecfb1a80cef346026671cb7 ]

Syscall handlers should not be invoked internally by their symbol names,
as these symbols defined by the architecture-defined SYSCALL_DEFINE
macro. Fortunately, in the case of ppc64_personality, its call to
sys_personality can be replaced with an invocation to the
equivalent ksys_personality inline helper in <linux/syscalls.h>.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-13-rmclure@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/syscalls.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
index 466216506eb2..94067b6979e4 100644
--- a/arch/powerpc/kernel/syscalls.c
+++ b/arch/powerpc/kernel/syscalls.c
@@ -109,7 +109,7 @@ long ppc64_personality(unsigned long personality)
 	if (personality(current->personality) == PER_LINUX32
 	    && personality(personality) == PER_LINUX)
 		personality = (personality & ~PER_MASK) | PER_LINUX32;
-	ret = sys_personality(personality);
+	ret = ksys_personality(personality);
 	if (personality(ret) == PER_LINUX32)
 		ret = (ret & ~PER_MASK) | PER_LINUX;
 	return ret;
-- 
2.35.1

[PATCH AUTOSEL 4.19 4/5] powerpc/mm: Fix UBSAN warning reported on hugetlb

[Sasha Levin]

From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>

[ Upstream commit 7dd3a7b90bca2c12e2146a47d63cf69a2f5d7e89 ]

Powerpc architecture supports 16GB hugetlb pages with hash translation.
For 4K page size, this is implemented as a hugepage directory entry at
PGD level and for 64K it is implemented as a huge page pte at PUD level

With 16GB hugetlb size, offset within a page is greater than 32 bits.
Hence switch to use unsigned long type when using hugepd_shift.

In order to keep things simpler, we make sure we always use unsigned
long type when using hugepd_shift() even though all the hugetlb page
size won't require that.

The hugetlb_free_p*d_range changes are all related to nohash usage where
we can have multiple pgd entries pointing to the same hugepd entries.
Hence on book3s64 where we can have > 4GB hugetlb page size we will
always find more < next even if we compute the value of more correctly.

Hence there is no functional change in this patch except that it fixes
the below warning.

  UBSAN: shift-out-of-bounds in arch/powerpc/mm/hugetlbpage.c:499:21
  shift exponent 34 is too large for 32-bit type 'int'
  CPU: 39 PID: 1673 Comm: a.out Not tainted 6.0.0-rc2-00327-gee88a56e8517-dirty #1
  Call Trace:
    dump_stack_lvl+0x98/0xe0 (unreliable)
    ubsan_epilogue+0x18/0x70
    __ubsan_handle_shift_out_of_bounds+0x1bc/0x390
    hugetlb_free_pgd_range+0x5d8/0x600
    free_pgtables+0x114/0x290
    exit_mmap+0x150/0x550
    mmput+0xcc/0x210
    do_exit+0x420/0xdd0
    do_group_exit+0x4c/0xd0
    sys_exit_group+0x24/0x30
    system_call_exception+0x250/0x600
    system_call_common+0xec/0x250

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Drop generic change to be sent separately, change 1ULL to 1UL]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220908072440.258301-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/mm/hugetlbpage.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index cef0b7ee1024..a2e28e235fd8 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -371,7 +371,7 @@ static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
 		 * single hugepage, but all of them point to
 		 * the same kmem cache that holds the hugepte.
 		 */
-		more = addr + (1 << hugepd_shift(*(hugepd_t *)pmd));
+		more = addr + (1UL << hugepd_shift(*(hugepd_t *)pmd));
 		if (more > next)
 			next = more;
 
@@ -421,7 +421,7 @@ static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
 			 * single hugepage, but all of them point to
 			 * the same kmem cache that holds the hugepte.
 			 */
-			more = addr + (1 << hugepd_shift(*(hugepd_t *)pud));
+			more = addr + (1UL << hugepd_shift(*(hugepd_t *)pud));
 			if (more > next)
 				next = more;
 
@@ -489,7 +489,7 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb,
 			 * for a single hugepage, but all of them point to the
 			 * same kmem cache that holds the hugepte.
 			 */
-			more = addr + (1 << hugepd_shift(*(hugepd_t *)pgd));
+			more = addr + (1UL << hugepd_shift(*(hugepd_t *)pgd));
 			if (more > next)
 				next = more;
 
-- 
2.35.1

[PATCH AUTOSEL 4.19 5/5] powerpc/64: Fix msr_check_and_set/clear MSR[EE] race

[Sasha Levin]

From: Nicholas Piggin <npiggin@gmail.com>

[ Upstream commit 0fa6831811f62cfc10415d731bcf9fde2647ad81 ]

irq soft-masking means that when Linux irqs are disabled, the MSR[EE]
value can change from 1 to 0 asynchronously: if a masked interrupt of
the PACA_IRQ_MUST_HARD_MASK variety fires while irqs are disabled,
the masked handler will return with MSR[EE]=0.

This means a sequence like mtmsr(mfmsr() | MSR_FP) is racy if it can
be called with local irqs disabled, unless a hard_irq_disable has been
done.

Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221004051157.308999-2-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/include/asm/hw_irq.h | 24 ++++++++++++++++++++++++
 arch/powerpc/kernel/process.c     |  4 ++--
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index 32a18f2f49bc..3ef454f99d24 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -353,6 +353,30 @@ static inline void may_hard_irq_enable(void) { }
 
 #endif /* CONFIG_PPC64 */
 
+static inline unsigned long mtmsr_isync_irqsafe(unsigned long msr)
+{
+#ifdef CONFIG_PPC64
+	if (arch_irqs_disabled()) {
+		/*
+		 * With soft-masking, MSR[EE] can change from 1 to 0
+		 * asynchronously when irqs are disabled, and we don't want to
+		 * set MSR[EE] back to 1 here if that has happened. A race-free
+		 * way to do this is ensure EE is already 0. Another way it
+		 * could be done is with a RESTART_TABLE handler, but that's
+		 * probably overkill here.
+		 */
+		msr &= ~MSR_EE;
+		mtmsr_isync(msr);
+		irq_soft_mask_set(IRQS_ALL_DISABLED);
+		local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
+	} else
+#endif
+		mtmsr_isync(msr);
+
+	return msr;
+}
+
+
 #define ARCH_IRQ_INIT_FLAGS	IRQ_NOREQUEST
 
 /*
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 9f89fac4ed08..a703b98ced11 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -131,7 +131,7 @@ unsigned long msr_check_and_set(unsigned long bits)
 #endif
 
 	if (oldmsr != newmsr)
-		mtmsr_isync(newmsr);
+		newmsr = mtmsr_isync_irqsafe(newmsr);
 
 	return newmsr;
 }
@@ -150,7 +150,7 @@ void __msr_check_and_clear(unsigned long bits)
 #endif
 
 	if (oldmsr != newmsr)
-		mtmsr_isync(newmsr);
+		mtmsr_isync_irqsafe(newmsr);
 }
 EXPORT_SYMBOL(__msr_check_and_clear);
 
-- 
2.35.1