[PATCH AUTOSEL 5.15 02/12] powerpc/mm: Fix null-pointer dereference in pgtable_cache_add

[PATCH AUTOSEL 5.15 02/12] powerpc/mm: Fix null-pointer dereference in pgtable_cache_add

[Sasha Levin]

From: Kunwu Chan <chentao@kylinos.cn>

[ Upstream commit f46c8a75263f97bda13c739ba1c90aced0d3b071 ]

kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure. Ensure the allocation was successful
by checking the pointer validity.

Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231204023223.2447523-1-chentao@kylinos.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/mm/init-common.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c
index 3a82f89827a5..4bc8f0c893a2 100644
--- a/arch/powerpc/mm/init-common.c
+++ b/arch/powerpc/mm/init-common.c
@@ -105,7 +105,7 @@ void pgtable_cache_add(unsigned int shift)
 	 * as to leave enough 0 bits in the address to contain it. */
 	unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1,
 				     HUGEPD_SHIFT_MASK + 1);
-	struct kmem_cache *new;
+	struct kmem_cache *new = NULL;
 
 	/* It would be nice if this was a BUILD_BUG_ON(), but at the
 	 * moment, gcc doesn't seem to recognize is_power_of_2 as a
@@ -118,7 +118,8 @@ void pgtable_cache_add(unsigned int shift)
 
 	align = max_t(unsigned long, align, minalign);
 	name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
-	new = kmem_cache_create(name, table_size, align, 0, ctor(shift));
+	if (name)
+		new = kmem_cache_create(name, table_size, align, 0, ctor(shift));
 	if (!new)
 		panic("Could not allocate pgtable cache for order %d", shift);
 
-- 
2.43.0

[PATCH AUTOSEL 5.15 05/12] powerpc: Fix build error due to is_valid_bugaddr()

[Sasha Levin]

From: Michael Ellerman <mpe@ellerman.id.au>

[ Upstream commit f8d3555355653848082c351fa90775214fb8a4fa ]

With CONFIG_GENERIC_BUG=n the build fails with:

  arch/powerpc/kernel/traps.c:1442:5: error: no previous prototype for ‘is_valid_bugaddr’ [-Werror=missing-prototypes]
  1442 | int is_valid_bugaddr(unsigned long addr)
       |     ^~~~~~~~~~~~~~~~

The prototype is only defined, and the function is only needed, when
CONFIG_GENERIC_BUG=y, so move the implementation under that.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231130114433.3053544-2-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/kernel/traps.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index fe912983ced9..f1a2a75c4757 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1423,10 +1423,12 @@ static int emulate_instruction(struct pt_regs *regs)
 	return -EINVAL;
 }
 
+#ifdef CONFIG_GENERIC_BUG
 int is_valid_bugaddr(unsigned long addr)
 {
 	return is_kernel_addr(addr);
 }
+#endif
 
 #ifdef CONFIG_MATH_EMULATION
 static int emulate_math(struct pt_regs *regs)
-- 
2.43.0

[PATCH AUTOSEL 5.15 06/12] powerpc/mm: Fix build failures due to arch_reserved_kernel_pages()

[Sasha Levin]

From: Michael Ellerman <mpe@ellerman.id.au>

[ Upstream commit d8c3f243d4db24675b653f0568bb65dae34e6455 ]

With NUMA=n and FA_DUMP=y or PRESERVE_FA_DUMP=y the build fails with:

  arch/powerpc/kernel/fadump.c:1739:22: error: no previous prototype for ‘arch_reserved_kernel_pages’ [-Werror=missing-prototypes]
  1739 | unsigned long __init arch_reserved_kernel_pages(void)
       |                      ^~~~~~~~~~~~~~~~~~~~~~~~~~

The prototype for arch_reserved_kernel_pages() is in include/linux/mm.h,
but it's guarded by __HAVE_ARCH_RESERVED_KERNEL_PAGES. The powerpc
headers define __HAVE_ARCH_RESERVED_KERNEL_PAGES in asm/mmzone.h, which
is not included into the generic headers when NUMA=n.

Move the definition of __HAVE_ARCH_RESERVED_KERNEL_PAGES into asm/mmu.h
which is included regardless of NUMA=n.

Additionally the ifdef around __HAVE_ARCH_RESERVED_KERNEL_PAGES needs to
also check for CONFIG_PRESERVE_FA_DUMP.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231130114433.3053544-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/include/asm/mmu.h    | 4 ++++
 arch/powerpc/include/asm/mmzone.h | 3 ---
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index 8abe8e42e045..de0bb77f54e0 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -416,5 +416,9 @@ extern void *abatron_pteptrs[2];
 #include <asm/nohash/mmu.h>
 #endif
 
+#if defined(CONFIG_FA_DUMP) || defined(CONFIG_PRESERVE_FA_DUMP)
+#define __HAVE_ARCH_RESERVED_KERNEL_PAGES
+#endif
+
 #endif /* __KERNEL__ */
 #endif /* _ASM_POWERPC_MMU_H_ */
diff --git a/arch/powerpc/include/asm/mmzone.h b/arch/powerpc/include/asm/mmzone.h
index 4c6c6dbd182f..3764d3585d30 100644
--- a/arch/powerpc/include/asm/mmzone.h
+++ b/arch/powerpc/include/asm/mmzone.h
@@ -42,9 +42,6 @@ u64 memory_hotplug_max(void);
 #else
 #define memory_hotplug_max() memblock_end_of_DRAM()
 #endif /* CONFIG_NUMA */
-#ifdef CONFIG_FA_DUMP
-#define __HAVE_ARCH_RESERVED_KERNEL_PAGES
-#endif
 
 #ifdef CONFIG_MEMORY_HOTPLUG
 extern int create_section_mapping(unsigned long start, unsigned long end,
-- 
2.43.0

[PATCH AUTOSEL 5.15 07/12] powerpc/64s: Fix CONFIG_NUMA=n build due to create_section_mapping()

[Sasha Levin]

From: Michael Ellerman <mpe@ellerman.id.au>

[ Upstream commit ede66cd22441820cbd399936bf84fdc4294bc7fa ]

With CONFIG_NUMA=n the build fails with:

  arch/powerpc/mm/book3s64/pgtable.c:275:15: error: no previous prototype for ‘create_section_mapping’ [-Werror=missing-prototypes]
  275 | int __meminit create_section_mapping(unsigned long start, unsigned long end,
      |               ^~~~~~~~~~~~~~~~~~~~~~

That happens because the prototype for create_section_mapping() is in
asm/mmzone.h, but asm/mmzone.h is only included by linux/mmzone.h
when CONFIG_NUMA=y.

In fact the prototype is only needed by arch/powerpc/mm code, so move
the prototype into arch/powerpc/mm/mmu_decl.h, which also fixes the
build error.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231129131919.2528517-5-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/include/asm/mmzone.h | 5 -----
 arch/powerpc/mm/mmu_decl.h        | 5 +++++
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/mmzone.h b/arch/powerpc/include/asm/mmzone.h
index 3764d3585d30..da827d2d0866 100644
--- a/arch/powerpc/include/asm/mmzone.h
+++ b/arch/powerpc/include/asm/mmzone.h
@@ -43,10 +43,5 @@ u64 memory_hotplug_max(void);
 #define memory_hotplug_max() memblock_end_of_DRAM()
 #endif /* CONFIG_NUMA */
 
-#ifdef CONFIG_MEMORY_HOTPLUG
-extern int create_section_mapping(unsigned long start, unsigned long end,
-				  int nid, pgprot_t prot);
-#endif
-
 #endif /* __KERNEL__ */
 #endif /* _ASM_MMZONE_H_ */
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index dd1cabc2ea0f..21996b9e0a64 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -190,3 +190,8 @@ static inline bool debug_pagealloc_enabled_or_kfence(void)
 {
 	return IS_ENABLED(CONFIG_KFENCE) || debug_pagealloc_enabled();
 }
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+int create_section_mapping(unsigned long start, unsigned long end,
+			   int nid, pgprot_t prot);
+#endif
-- 
2.43.0

[PATCH AUTOSEL 5.15 09/12] powerpc: pmd_move_must_withdraw() is only needed for CONFIG_TRANSPARENT_HUGEPAGE

[Sasha Levin]

From: Stephen Rothwell <sfr@canb.auug.org.au>

[ Upstream commit 0d555b57ee660d8a871781c0eebf006e855e918d ]

The linux-next build of powerpc64 allnoconfig fails with:

  arch/powerpc/mm/book3s64/pgtable.c:557:5: error: no previous prototype for 'pmd_move_must_withdraw'
    557 | int pmd_move_must_withdraw(struct spinlock *new_pmd_ptl,
        |     ^~~~~~~~~~~~~~~~~~~~~~

Caused by commit:

  c6345dfa6e3e ("Makefile.extrawarn: turn on missing-prototypes globally")

Fix it by moving the function definition under
CONFIG_TRANSPARENT_HUGEPAGE like the prototype. The function is only
called when CONFIG_TRANSPARENT_HUGEPAGE=y.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
[mpe: Flesh out change log from linux-next patch]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231127132809.45c2b398@canb.auug.org.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/mm/book3s64/pgtable.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index 9e16c7b1a6c5..da15f28c7b13 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -459,6 +459,7 @@ void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
 	set_pte_at(vma->vm_mm, addr, ptep, pte);
 }
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 /*
  * For hash translation mode, we use the deposited table to store hash slot
  * information and they are stored at PTRS_PER_PMD offset from related pmd
@@ -480,6 +481,7 @@ int pmd_move_must_withdraw(struct spinlock *new_pmd_ptl,
 
 	return true;
 }
+#endif
 
 /*
  * Does the CPU support tlbie?
-- 
2.43.0

[PATCH AUTOSEL 5.15 10/12] powerpc/lib: Validate size for vector operations

[Sasha Levin]

From: Naveen N Rao <naveen@kernel.org>

[ Upstream commit 8f9abaa6d7de0a70fc68acaedce290c1f96e2e59 ]

Some of the fp/vmx code in sstep.c assume a certain maximum size for the
instructions being emulated. The size of those operations however is
determined separately in analyse_instr().

Add a check to validate the assumption on the maximum size of the
operations, so as to prevent any unintended kernel stack corruption.

Signed-off-by: Naveen N Rao <naveen@kernel.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Build-tested-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231123071705.397625-1-naveen@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/lib/sstep.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 2d39b7c246e3..ecc2e06854d7 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -529,6 +529,8 @@ static int do_fp_load(struct instruction_op *op, unsigned long ea,
 	} u;
 
 	nb = GETSIZE(op->type);
+	if (nb > sizeof(u))
+		return -EINVAL;
 	if (!address_ok(regs, ea, nb))
 		return -EFAULT;
 	rn = op->reg;
@@ -579,6 +581,8 @@ static int do_fp_store(struct instruction_op *op, unsigned long ea,
 	} u;
 
 	nb = GETSIZE(op->type);
+	if (nb > sizeof(u))
+		return -EINVAL;
 	if (!address_ok(regs, ea, nb))
 		return -EFAULT;
 	rn = op->reg;
@@ -623,6 +627,9 @@ static nokprobe_inline int do_vec_load(int rn, unsigned long ea,
 		u8 b[sizeof(__vector128)];
 	} u = {};
 
+	if (size > sizeof(u))
+		return -EINVAL;
+
 	if (!address_ok(regs, ea & ~0xfUL, 16))
 		return -EFAULT;
 	/* align to multiple of size */
@@ -650,6 +657,9 @@ static nokprobe_inline int do_vec_store(int rn, unsigned long ea,
 		u8 b[sizeof(__vector128)];
 	} u;
 
+	if (size > sizeof(u))
+		return -EINVAL;
+
 	if (!address_ok(regs, ea & ~0xfUL, 16))
 		return -EFAULT;
 	/* align to multiple of size */
-- 
2.43.0