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* [PATCH v6 7/7] KVM: PPC: Ultravisor: Add PPC_UV config option
From: Bharata B Rao @ 2019-08-09  8:41 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: linuxram, cclaudio, kvm-ppc, Bharata B Rao, linux-mm, jglisse,
	aneesh.kumar, paulus, sukadev, hch, Anshuman Khandual
In-Reply-To: <20190809084108.30343-1-bharata@linux.ibm.com>

From: Anshuman Khandual <khandual@linux.vnet.ibm.com>

CONFIG_PPC_UV adds support for ultravisor.

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[ Update config help and commit message ]
Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
---
 arch/powerpc/Kconfig | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index d8dcd8820369..8b36ca5ed3b0 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -448,6 +448,24 @@ config PPC_TRANSACTIONAL_MEM
 	help
 	  Support user-mode Transactional Memory on POWERPC.
 
+config PPC_UV
+	bool "Ultravisor support"
+	depends on KVM_BOOK3S_HV_POSSIBLE
+	select ZONE_DEVICE
+	select MIGRATE_VMA_HELPER
+	select DEV_PAGEMAP_OPS
+	select DEVICE_PRIVATE
+	select MEMORY_HOTPLUG
+	select MEMORY_HOTREMOVE
+	default n
+	help
+	  This option paravirtualizes the kernel to run in POWER platforms that
+	  supports the Protected Execution Facility (PEF). In such platforms,
+	  the ultravisor firmware runs at a privilege level above the
+	  hypervisor.
+
+	  If unsure, say "N".
+
 config LD_HEAD_STUB_CATCH
 	bool "Reserve 256 bytes to cope with linker stubs in HEAD text" if EXPERT
 	depends on PPC64
-- 
2.21.0


^ permalink raw reply related

* Re: [PATCH 1/2] powerpc: Allow flush_icache_range to work across ranges >4GB
From: Christophe Leroy @ 2019-08-09  8:59 UTC (permalink / raw)
  To: Alastair D'Silva, alastair
  Cc: linux-kernel, stable, Paul Mackerras, Greg Kroah-Hartman,
	Thomas Gleixner, linuxppc-dev
In-Reply-To: <20190809004548.22445-1-alastair@au1.ibm.com>



Le 09/08/2019 à 02:45, Alastair D'Silva a écrit :
> From: Alastair D'Silva <alastair@d-silva.org>
> 
> When calling flush_icache_range with a size >4GB, we were masking
> off the upper 32 bits, so we would incorrectly flush a range smaller
> than intended.
> 
> This patch replaces the 32 bit shifts with 64 bit ones, so that
> the full size is accounted for.
> 
> Heads-up for backporters: the old version of flush_dcache_range is
> subject to a similar bug (this has since been replaced with a C
> implementation).

Can you submit a patch to stable, explaining this ?

> 
> Signed-off-by: Alastair D'Silva <alastair@d-silva.org>

Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>

Should add:

Cc: stable@vger.kernel.org

Christophe

> ---
>   arch/powerpc/kernel/misc_64.S | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
> index b55a7b4cb543..9bc0aa9aeb65 100644
> --- a/arch/powerpc/kernel/misc_64.S
> +++ b/arch/powerpc/kernel/misc_64.S
> @@ -82,7 +82,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
>   	subf	r8,r6,r4		/* compute length */
>   	add	r8,r8,r5		/* ensure we get enough */
>   	lwz	r9,DCACHEL1LOGBLOCKSIZE(r10)	/* Get log-2 of cache block size */
> -	srw.	r8,r8,r9		/* compute line count */
> +	srd.	r8,r8,r9		/* compute line count */
>   	beqlr				/* nothing to do? */
>   	mtctr	r8
>   1:	dcbst	0,r6
> @@ -98,7 +98,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
>   	subf	r8,r6,r4		/* compute length */
>   	add	r8,r8,r5
>   	lwz	r9,ICACHEL1LOGBLOCKSIZE(r10)	/* Get log-2 of Icache block size */
> -	srw.	r8,r8,r9		/* compute line count */
> +	srd.	r8,r8,r9		/* compute line count */
>   	beqlr				/* nothing to do? */
>   	mtctr	r8
>   2:	icbi	0,r6
> 

^ permalink raw reply

* Re: [PATCH 2/2] powerpc: Convert flush_icache_range to C
From: Christophe Leroy @ 2019-08-09  9:23 UTC (permalink / raw)
  To: Alastair D'Silva, alastair
  Cc: linux-kernel, Qian Cai, Greg Kroah-Hartman, Paul Mackerras,
	Thomas Gleixner, linuxppc-dev, Allison Randal
In-Reply-To: <20190809004658.22512-1-alastair@au1.ibm.com>



Le 09/08/2019 à 02:46, Alastair D'Silva a écrit :
> From: Alastair D'Silva <alastair@d-silva.org>
> 
> Similar to commit 22e9c88d486a
> ("powerpc/64: reuse PPC32 static inline flush_dcache_range()")
> this patch converts flush_icache_range to C.

Should we also convert __flush_dcache_icache() which does exactly the 
same but on a full page ? We could most likely use the same code, ie 
call flush_icache_range() from __flush_dcache_icache() ?

> 
> This was done as we discovered a long-standing bug where the
> length of the range was truncated due to using a 32 bit shift
> instead of a 64 bit one.
> 
> By converting this function to C, it becomes easier to maintain.
> 
> Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
> ---
>   arch/powerpc/include/asm/cache.h      | 35 +++++++++++++--
>   arch/powerpc/include/asm/cacheflush.h | 63 +++++++++++++++++++++++----
>   arch/powerpc/kernel/misc_64.S         | 55 -----------------------

There is also a flush_icache_range() in arch/powerpc/kernel/misc_32.S, 
it must be converted as well.

>   3 files changed, 85 insertions(+), 68 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/cache.h b/arch/powerpc/include/asm/cache.h
> index b3388d95f451..d3d7077b75e2 100644
> --- a/arch/powerpc/include/asm/cache.h
> +++ b/arch/powerpc/include/asm/cache.h
> @@ -55,25 +55,46 @@ struct ppc64_caches {
>   
>   extern struct ppc64_caches ppc64_caches;
>   
> -static inline u32 l1_cache_shift(void)
> +static inline u32 l1_dcache_shift(void)
>   {
>   	return ppc64_caches.l1d.log_block_size;
>   }
>   
> -static inline u32 l1_cache_bytes(void)
> +static inline u32 l1_dcache_bytes(void)
>   {
>   	return ppc64_caches.l1d.block_size;
>   }
> +
> +static inline u32 l1_icache_shift(void)
> +{
> +	return ppc64_caches.l1i.log_block_size;
> +}
> +
> +static inline u32 l1_icache_bytes(void)
> +{
> +	return ppc64_caches.l1i.block_size;
> +}
>   #else
> -static inline u32 l1_cache_shift(void)
> +static inline u32 l1_dcache_shift(void)
>   {
>   	return L1_CACHE_SHIFT;
>   }
>   
> -static inline u32 l1_cache_bytes(void)
> +static inline u32 l1_dcache_bytes(void)
>   {
>   	return L1_CACHE_BYTES;
>   }
> +
> +static inline u32 l1_icache_shift(void)
> +{
> +	return L1_CACHE_SHIFT;
> +}
> +
> +static inline u32 l1_icache_bytes(void)
> +{
> +	return L1_CACHE_BYTES;
> +}
> +

Could the above adds/changes be a separate patch ?

>   #endif
>   #endif /* ! __ASSEMBLY__ */
>   
> @@ -124,6 +145,12 @@ static inline void dcbst(void *addr)
>   {
>   	__asm__ __volatile__ ("dcbst %y0" : : "Z"(*(u8 *)addr) : "memory");
>   }
> +
> +static inline void icbi(void *addr)
> +{
> +	__asm__ __volatile__ ("icbi %y0" : : "Z"(*(u8 *)addr) : "memory");
> +}
> +

Commit 6c5875843b87c3ad ("") is likely to be reverted in the near future 
due to a bug in CLANG and because it has no real benefit in our use cases.

So maybe you should consider using the previous format when adding icbi() ?

Should you also add iccci() in order to handle the 4xx part from misc_32 ?

>   #endif /* !__ASSEMBLY__ */
>   #endif /* __KERNEL__ */
>   #endif /* _ASM_POWERPC_CACHE_H */
> diff --git a/arch/powerpc/include/asm/cacheflush.h b/arch/powerpc/include/asm/cacheflush.h
> index eef388f2659f..f68e75a6dc4b 100644
> --- a/arch/powerpc/include/asm/cacheflush.h
> +++ b/arch/powerpc/include/asm/cacheflush.h
> @@ -42,7 +42,6 @@ extern void flush_dcache_page(struct page *page);
>   #define flush_dcache_mmap_lock(mapping)		do { } while (0)
>   #define flush_dcache_mmap_unlock(mapping)	do { } while (0)
>   
> -extern void flush_icache_range(unsigned long, unsigned long);
>   extern void flush_icache_user_range(struct vm_area_struct *vma,
>   				    struct page *page, unsigned long addr,
>   				    int len);
> @@ -57,14 +56,17 @@ static inline void __flush_dcache_icache_phys(unsigned long physaddr)
>   }
>   #endif
>   
> -/*
> - * Write any modified data cache blocks out to memory and invalidate them.
> +/**
> + * flush_dcache_range: Write any modified data cache blocks out to memory and invalidate them.
>    * Does not invalidate the corresponding instruction cache blocks.
> + *
> + * @start: the start address
> + * @stop: the stop address (exclusive)
>    */
>   static inline void flush_dcache_range(unsigned long start, unsigned long stop)
>   {
> -	unsigned long shift = l1_cache_shift();
> -	unsigned long bytes = l1_cache_bytes();
> +	unsigned long shift = l1_dcache_shift();
> +	unsigned long bytes = l1_dcache_bytes();
>   	void *addr = (void *)(start & ~(bytes - 1));
>   	unsigned long size = stop - (unsigned long)addr + (bytes - 1);
>   	unsigned long i;
> @@ -82,6 +84,49 @@ static inline void flush_dcache_range(unsigned long start, unsigned long stop)
>   		isync();
>   }
>   
> +/**
> + * flush_icache_range: Write any modified data cache blocks out to memory
> + * and invalidate the corresponding blocks in the instruction cache
> + *
> + * Generic code will call this after writing memory, before executing from it.
> + *
> + * @start: the start address
> + * @stop: the stop address (exclusive)
> + */
> +static inline void flush_icache_range(unsigned long start, unsigned long stop)

Wondering if it doesn't start to be a bit big for an inline function. 
Not sure thought. Maybe the addr and size calculation should remain 
inlined in order to benefit from constant inputs while the two loops and 
sync stuff around them could be a dedicated function ?

> +{
> +	unsigned long shift = l1_dcache_shift();
> +	unsigned long bytes = l1_dcache_bytes();
> +	void *addr = (void *)(start & ~(bytes - 1));
> +	unsigned long size = stop - (unsigned long)addr + (bytes - 1);
> +	unsigned long i;
> +
> +	if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) {
> +		mb(); /* sync */
> +		icbi((void *)start);
> +		mb(); /* sync */
> +		isync();
> +		return;
> +	}
> +
> +	/* Flush the data cache to memory */
> +	for (i = 0; i < size >> shift; i++, addr += bytes)
> +		dcbst(addr);
> +
> +	mb();	/* sync */
> +
> +	shift = l1_icache_shift();
> +	bytes = l1_icache_bytes();
> +	addr = (void *)(start & ~(bytes - 1));
> +	size = stop - (unsigned long)addr + (bytes - 1);
> +
> +	/* Now invalidate the instruction cache */
> +	for (i = 0; i < size >> shift; i++, addr += bytes)
> +		icbi(addr);
> +
> +	isync();
> +}

Don't forget to also take misc_32 into account.

Christophe

> +
>   /*
>    * Write any modified data cache blocks out to memory.
>    * Does not invalidate the corresponding cache lines (especially for
> @@ -89,8 +134,8 @@ static inline void flush_dcache_range(unsigned long start, unsigned long stop)
>    */
>   static inline void clean_dcache_range(unsigned long start, unsigned long stop)
>   {
> -	unsigned long shift = l1_cache_shift();
> -	unsigned long bytes = l1_cache_bytes();
> +	unsigned long shift = l1_dcache_shift();
> +	unsigned long bytes = l1_dcache_bytes();
>   	void *addr = (void *)(start & ~(bytes - 1));
>   	unsigned long size = stop - (unsigned long)addr + (bytes - 1);
>   	unsigned long i;
> @@ -108,8 +153,8 @@ static inline void clean_dcache_range(unsigned long start, unsigned long stop)
>   static inline void invalidate_dcache_range(unsigned long start,
>   					   unsigned long stop)
>   {
> -	unsigned long shift = l1_cache_shift();
> -	unsigned long bytes = l1_cache_bytes();
> +	unsigned long shift = l1_dcache_shift();
> +	unsigned long bytes = l1_dcache_bytes();
>   	void *addr = (void *)(start & ~(bytes - 1));
>   	unsigned long size = stop - (unsigned long)addr + (bytes - 1);
>   	unsigned long i;
> diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
> index 9bc0aa9aeb65..999828e86bba 100644
> --- a/arch/powerpc/kernel/misc_64.S
> +++ b/arch/powerpc/kernel/misc_64.S
> @@ -54,61 +54,6 @@ PPC64_CACHES:
>   	.tc		ppc64_caches[TC],ppc64_caches
>   	.section	".text"
>   
> -/*
> - * Write any modified data cache blocks out to memory
> - * and invalidate the corresponding instruction cache blocks.
> - *
> - * flush_icache_range(unsigned long start, unsigned long stop)
> - *
> - *   flush all bytes from start through stop-1 inclusive
> - */
> -
> -_GLOBAL_TOC(flush_icache_range)
> -BEGIN_FTR_SECTION
> -	PURGE_PREFETCHED_INS
> -	blr
> -END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
> -/*
> - * Flush the data cache to memory
> - *
> - * Different systems have different cache line sizes
> - * and in some cases i-cache and d-cache line sizes differ from
> - * each other.
> - */
> - 	ld	r10,PPC64_CACHES@toc(r2)
> -	lwz	r7,DCACHEL1BLOCKSIZE(r10)/* Get cache block size */
> -	addi	r5,r7,-1
> -	andc	r6,r3,r5		/* round low to line bdy */
> -	subf	r8,r6,r4		/* compute length */
> -	add	r8,r8,r5		/* ensure we get enough */
> -	lwz	r9,DCACHEL1LOGBLOCKSIZE(r10)	/* Get log-2 of cache block size */
> -	srd.	r8,r8,r9		/* compute line count */
> -	beqlr				/* nothing to do? */
> -	mtctr	r8
> -1:	dcbst	0,r6
> -	add	r6,r6,r7
> -	bdnz	1b
> -	sync
> -
> -/* Now invalidate the instruction cache */
> -	
> -	lwz	r7,ICACHEL1BLOCKSIZE(r10)	/* Get Icache block size */
> -	addi	r5,r7,-1
> -	andc	r6,r3,r5		/* round low to line bdy */
> -	subf	r8,r6,r4		/* compute length */
> -	add	r8,r8,r5
> -	lwz	r9,ICACHEL1LOGBLOCKSIZE(r10)	/* Get log-2 of Icache block size */
> -	srd.	r8,r8,r9		/* compute line count */
> -	beqlr				/* nothing to do? */
> -	mtctr	r8
> -2:	icbi	0,r6
> -	add	r6,r6,r7
> -	bdnz	2b
> -	isync
> -	blr
> -_ASM_NOKPROBE_SYMBOL(flush_icache_range)
> -EXPORT_SYMBOL(flush_icache_range)
> -
>   /*
>    * Flush a particular page from the data cache to RAM.
>    * Note: this is necessary because the instruction cache does *not*
> 

^ permalink raw reply

* Re: [PATCH 6/8] arm-nommu: call dma_mmap_from_dev_coherent directly
From: Sergei Shtylyov @ 2019-08-09  9:35 UTC (permalink / raw)
  To: Christoph Hellwig, iommu, Marek Szyprowski
  Cc: linux-xtensa, Michal Simek, Vladimir Murzin, linux-parisc,
	linux-sh, Takashi Iwai, linuxppc-dev, Helge Deller, x86,
	linux-kernel, linux-m68k, Robin Murphy, linux-arm-kernel
In-Reply-To: <20190808160005.10325-7-hch@lst.de>

On 08.08.2019 19:00, Christoph Hellwig wrote:

> Ther is no need to go through dma_common_mmap for the arm-nommu

    There. :-)

> dma mmap implementation as the only possible memory not handled above
> could be that from the per-device coherent pool.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
[...]

MBR, Sergei

^ permalink raw reply

* [PATCH v6 00/12] implement KASLR for powerpc/fsl_booke/32
From: Jason Yan @ 2019-08-09 10:07 UTC (permalink / raw)
  To: mpe, linuxppc-dev, diana.craciun, christophe.leroy, benh, paulus,
	npiggin, keescook, kernel-hardening
  Cc: wangkefeng.wang, Jason Yan, linux-kernel, jingxiangfeng,
	zhaohongjiang, thunder.leizhen, fanchengyang, yebin10

This series implements KASLR for powerpc/fsl_booke/32, as a security
feature that deters exploit attempts relying on knowledge of the location
of kernel internals.

Since CONFIG_RELOCATABLE has already supported, what we need to do is
map or copy kernel to a proper place and relocate. Freescale Book-E
parts expect lowmem to be mapped by fixed TLB entries(TLB1). The TLB1
entries are not suitable to map the kernel directly in a randomized
region, so we chose to copy the kernel to a proper place and restart to
relocate.

Entropy is derived from the banner and timer base, which will change every
build and boot. This not so much safe so additionally the bootloader may
pass entropy via the /chosen/kaslr-seed node in device tree.

We will use the first 512M of the low memory to randomize the kernel
image. The memory will be split in 64M zones. We will use the lower 8
bit of the entropy to decide the index of the 64M zone. Then we chose a
16K aligned offset inside the 64M zone to put the kernel in.

    KERNELBASE

        |-->   64M   <--|
        |               |
        +---------------+    +----------------+---------------+
        |               |....|    |kernel|    |               |
        +---------------+    +----------------+---------------+
        |                         |
        |----->   offset    <-----|

                              kernstart_virt_addr

We also check if we will overlap with some areas like the dtb area, the
initrd area or the crashkernel area. If we cannot find a proper area,
kaslr will be disabled and boot from the original kernel.

Changes since v5:
 - Rename M_IF_NEEDED to MAS2_M_IF_NEEDED
 - Define some global variable as __ro_after_init
 - Replace kimage_vaddr with kernstart_virt_addr
 - Depend on RELOCATABLE, not select it
 - Modify the comment block below the SPDX tag
 - Remove some useless headers in kaslr_booke.c and move is_second_reloc
   declarationto mmu_decl.h
 - Remove DBG() and use pr_debug() and rewrite comment above get_boot_seed().
 - Add a patch to document the KASLR implementation.
 - Split a patch from patch #10 which exports kaslr offset in VMCOREINFO ELF notes.
 - Remove extra logic around finding nokaslr string in cmdline.
 - Make regions static global and __initdata

Changes since v4:
 - Add Reviewed-by tag from Christophe
 - Remove an unnecessary cast
 - Remove unnecessary parenthesis
 - Fix checkpatch warning

Changes since v3:
 - Add Reviewed-by and Tested-by tag from Diana
 - Change the comment in fsl_booke_entry_mapping.S to be consistent
   with the new code.

Changes since v2:
 - Remove unnecessary #ifdef
 - Use SZ_64M instead of0x4000000
 - Call early_init_dt_scan_chosen() to init boot_command_line
 - Rename kaslr_second_init() to kaslr_late_init()

Changes since v1:
 - Remove some useless 'extern' keyword.
 - Replace EXPORT_SYMBOL with EXPORT_SYMBOL_GPL
 - Improve some assembly code
 - Use memzero_explicit instead of memset
 - Use boot_command_line and remove early_command_line
 - Do not print kaslr offset if kaslr is disabled

Jason Yan (12):
  powerpc: unify definition of M_IF_NEEDED
  powerpc: move memstart_addr and kernstart_addr to init-common.c
  powerpc: introduce kernstart_virt_addr to store the kernel base
  powerpc/fsl_booke/32: introduce create_tlb_entry() helper
  powerpc/fsl_booke/32: introduce reloc_kernel_entry() helper
  powerpc/fsl_booke/32: implement KASLR infrastructure
  powerpc/fsl_booke/32: randomize the kernel image offset
  powerpc/fsl_booke/kaslr: clear the original kernel if randomized
  powerpc/fsl_booke/kaslr: support nokaslr cmdline parameter
  powerpc/fsl_booke/kaslr: dump out kernel offset information on panic
  powerpc/fsl_booke/kaslr: export offset in VMCOREINFO ELF notes
  powerpc/fsl_booke/32: Document KASLR implementation

 Documentation/powerpc/kaslr-booke32.rst       |  42 ++
 arch/powerpc/Kconfig                          |  11 +
 arch/powerpc/include/asm/nohash/mmu-book3e.h  |  10 +
 arch/powerpc/include/asm/page.h               |   7 +
 arch/powerpc/kernel/Makefile                  |   1 +
 arch/powerpc/kernel/early_32.c                |   2 +-
 arch/powerpc/kernel/exceptions-64e.S          |  12 +-
 arch/powerpc/kernel/fsl_booke_entry_mapping.S |  27 +-
 arch/powerpc/kernel/head_fsl_booke.S          |  55 ++-
 arch/powerpc/kernel/kaslr_booke.c             | 393 ++++++++++++++++++
 arch/powerpc/kernel/machine_kexec.c           |   1 +
 arch/powerpc/kernel/misc_64.S                 |   7 +-
 arch/powerpc/kernel/setup-common.c            |  20 +
 arch/powerpc/mm/init-common.c                 |   7 +
 arch/powerpc/mm/init_32.c                     |   5 -
 arch/powerpc/mm/init_64.c                     |   5 -
 arch/powerpc/mm/mmu_decl.h                    |  11 +
 arch/powerpc/mm/nohash/fsl_booke.c            |   8 +-
 18 files changed, 572 insertions(+), 52 deletions(-)
 create mode 100644 Documentation/powerpc/kaslr-booke32.rst
 create mode 100644 arch/powerpc/kernel/kaslr_booke.c

-- 
2.17.2


^ permalink raw reply

* [PATCH v6 03/12] powerpc: introduce kernstart_virt_addr to store the kernel base
From: Jason Yan @ 2019-08-09 10:07 UTC (permalink / raw)
  To: mpe, linuxppc-dev, diana.craciun, christophe.leroy, benh, paulus,
	npiggin, keescook, kernel-hardening
  Cc: wangkefeng.wang, Jason Yan, linux-kernel, jingxiangfeng,
	zhaohongjiang, thunder.leizhen, fanchengyang, yebin10
In-Reply-To: <20190809100800.5426-1-yanaijie@huawei.com>

Now the kernel base is a fixed value - KERNELBASE. To support KASLR, we
need a variable to store the kernel base.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Diana Craciun <diana.craciun@nxp.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
---
 arch/powerpc/include/asm/page.h | 2 ++
 arch/powerpc/mm/init-common.c   | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 0d52f57fca04..4d32d1b561d6 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -315,6 +315,8 @@ void arch_free_page(struct page *page, int order);
 
 struct vm_area_struct;
 
+extern unsigned long kernstart_virt_addr;
+
 #include <asm-generic/memory_model.h>
 #endif /* __ASSEMBLY__ */
 #include <asm/slice.h>
diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c
index e223da482c0c..42ef7a6e6098 100644
--- a/arch/powerpc/mm/init-common.c
+++ b/arch/powerpc/mm/init-common.c
@@ -25,6 +25,8 @@ phys_addr_t memstart_addr __ro_after_init = (phys_addr_t)~0ull;
 EXPORT_SYMBOL_GPL(memstart_addr);
 phys_addr_t kernstart_addr __ro_after_init;
 EXPORT_SYMBOL_GPL(kernstart_addr);
+unsigned long kernstart_virt_addr __ro_after_init = KERNELBASE;
+EXPORT_SYMBOL_GPL(kernstart_virt_addr);
 
 static bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP);
 static bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP);
-- 
2.17.2


^ permalink raw reply related

* [PATCH v6 02/12] powerpc: move memstart_addr and kernstart_addr to init-common.c
From: Jason Yan @ 2019-08-09 10:07 UTC (permalink / raw)
  To: mpe, linuxppc-dev, diana.craciun, christophe.leroy, benh, paulus,
	npiggin, keescook, kernel-hardening
  Cc: wangkefeng.wang, Jason Yan, linux-kernel, jingxiangfeng,
	zhaohongjiang, thunder.leizhen, fanchengyang, yebin10
In-Reply-To: <20190809100800.5426-1-yanaijie@huawei.com>

These two variables are both defined in init_32.c and init_64.c. Move
them to init-common.c and make them __ro_after_init.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Diana Craciun <diana.craciun@nxp.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
---
 arch/powerpc/mm/init-common.c | 5 +++++
 arch/powerpc/mm/init_32.c     | 5 -----
 arch/powerpc/mm/init_64.c     | 5 -----
 3 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c
index a84da92920f7..e223da482c0c 100644
--- a/arch/powerpc/mm/init-common.c
+++ b/arch/powerpc/mm/init-common.c
@@ -21,6 +21,11 @@
 #include <asm/pgtable.h>
 #include <asm/kup.h>
 
+phys_addr_t memstart_addr __ro_after_init = (phys_addr_t)~0ull;
+EXPORT_SYMBOL_GPL(memstart_addr);
+phys_addr_t kernstart_addr __ro_after_init;
+EXPORT_SYMBOL_GPL(kernstart_addr);
+
 static bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP);
 static bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP);
 
diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c
index b04896a88d79..872df48ae41b 100644
--- a/arch/powerpc/mm/init_32.c
+++ b/arch/powerpc/mm/init_32.c
@@ -56,11 +56,6 @@
 phys_addr_t total_memory;
 phys_addr_t total_lowmem;
 
-phys_addr_t memstart_addr = (phys_addr_t)~0ull;
-EXPORT_SYMBOL(memstart_addr);
-phys_addr_t kernstart_addr;
-EXPORT_SYMBOL(kernstart_addr);
-
 #ifdef CONFIG_RELOCATABLE
 /* Used in __va()/__pa() */
 long long virt_phys_offset;
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index a44f6281ca3a..c836f1269ee7 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c
@@ -63,11 +63,6 @@
 
 #include <mm/mmu_decl.h>
 
-phys_addr_t memstart_addr = ~0;
-EXPORT_SYMBOL_GPL(memstart_addr);
-phys_addr_t kernstart_addr;
-EXPORT_SYMBOL_GPL(kernstart_addr);
-
 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 /*
  * Given an address within the vmemmap, determine the pfn of the page that
-- 
2.17.2


^ permalink raw reply related

* [PATCH v6 01/12] powerpc: unify definition of M_IF_NEEDED
From: Jason Yan @ 2019-08-09 10:07 UTC (permalink / raw)
  To: mpe, linuxppc-dev, diana.craciun, christophe.leroy, benh, paulus,
	npiggin, keescook, kernel-hardening
  Cc: wangkefeng.wang, Jason Yan, linux-kernel, jingxiangfeng,
	zhaohongjiang, thunder.leizhen, fanchengyang, yebin10
In-Reply-To: <20190809100800.5426-1-yanaijie@huawei.com>

M_IF_NEEDED is defined too many times. Move it to a common place and
rename it to MAS2_M_IF_NEEDED which is much readable.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Diana Craciun <diana.craciun@nxp.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
---
 arch/powerpc/include/asm/nohash/mmu-book3e.h  | 10 ++++++++++
 arch/powerpc/kernel/exceptions-64e.S          | 12 +-----------
 arch/powerpc/kernel/fsl_booke_entry_mapping.S | 14 ++------------
 arch/powerpc/kernel/misc_64.S                 |  7 +------
 4 files changed, 14 insertions(+), 29 deletions(-)

diff --git a/arch/powerpc/include/asm/nohash/mmu-book3e.h b/arch/powerpc/include/asm/nohash/mmu-book3e.h
index 4c9777d256fb..fa3efc2d310f 100644
--- a/arch/powerpc/include/asm/nohash/mmu-book3e.h
+++ b/arch/powerpc/include/asm/nohash/mmu-book3e.h
@@ -221,6 +221,16 @@
 #define TLBILX_T_CLASS2			6
 #define TLBILX_T_CLASS3			7
 
+/*
+ * The mapping only needs to be cache-coherent on SMP, except on
+ * Freescale e500mc derivatives where it's also needed for coherent DMA.
+ */
+#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC)
+#define MAS2_M_IF_NEEDED	MAS2_M
+#else
+#define MAS2_M_IF_NEEDED	0
+#endif
+
 #ifndef __ASSEMBLY__
 #include <asm/bug.h>
 
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 1cfb3da4a84a..c5bc09b5e281 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -1342,16 +1342,6 @@ skpinv:	addi	r6,r6,1				/* Increment */
 	sync
 	isync
 
-/*
- * The mapping only needs to be cache-coherent on SMP, except on
- * Freescale e500mc derivatives where it's also needed for coherent DMA.
- */
-#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC)
-#define M_IF_NEEDED	MAS2_M
-#else
-#define M_IF_NEEDED	0
-#endif
-
 /* 6. Setup KERNELBASE mapping in TLB[0]
  *
  * r3 = MAS0 w/TLBSEL & ESEL for the entry we started in
@@ -1364,7 +1354,7 @@ skpinv:	addi	r6,r6,1				/* Increment */
 	ori	r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_1GB))@l
 	mtspr	SPRN_MAS1,r6
 
-	LOAD_REG_IMMEDIATE(r6, PAGE_OFFSET | M_IF_NEEDED)
+	LOAD_REG_IMMEDIATE(r6, PAGE_OFFSET | MAS2_M_IF_NEEDED)
 	mtspr	SPRN_MAS2,r6
 
 	rlwinm	r5,r5,0,0,25
diff --git a/arch/powerpc/kernel/fsl_booke_entry_mapping.S b/arch/powerpc/kernel/fsl_booke_entry_mapping.S
index ea065282b303..f4d3eaae54a9 100644
--- a/arch/powerpc/kernel/fsl_booke_entry_mapping.S
+++ b/arch/powerpc/kernel/fsl_booke_entry_mapping.S
@@ -153,16 +153,6 @@ skpinv:	addi	r6,r6,1				/* Increment */
 	tlbivax 0,r9
 	TLBSYNC
 
-/*
- * The mapping only needs to be cache-coherent on SMP, except on
- * Freescale e500mc derivatives where it's also needed for coherent DMA.
- */
-#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC)
-#define M_IF_NEEDED	MAS2_M
-#else
-#define M_IF_NEEDED	0
-#endif
-
 #if defined(ENTRY_MAPPING_BOOT_SETUP)
 
 /* 6. Setup KERNELBASE mapping in TLB1[0] */
@@ -171,8 +161,8 @@ skpinv:	addi	r6,r6,1				/* Increment */
 	lis	r6,(MAS1_VALID|MAS1_IPROT)@h
 	ori	r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_64M))@l
 	mtspr	SPRN_MAS1,r6
-	lis	r6,MAS2_VAL(PAGE_OFFSET, BOOK3E_PAGESZ_64M, M_IF_NEEDED)@h
-	ori	r6,r6,MAS2_VAL(PAGE_OFFSET, BOOK3E_PAGESZ_64M, M_IF_NEEDED)@l
+	lis	r6,MAS2_VAL(PAGE_OFFSET, BOOK3E_PAGESZ_64M, MAS2_M_IF_NEEDED)@h
+	ori	r6,r6,MAS2_VAL(PAGE_OFFSET, BOOK3E_PAGESZ_64M, MAS2_M_IF_NEEDED)@l
 	mtspr	SPRN_MAS2,r6
 	mtspr	SPRN_MAS3,r8
 	tlbwe
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index b55a7b4cb543..2062a299a22d 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -432,18 +432,13 @@ kexec_create_tlb:
 	rlwimi	r9,r10,16,4,15		/* Setup MAS0 = TLBSEL | ESEL(r9) */
 
 /* Set up a temp identity mapping v:0 to p:0 and return to it. */
-#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC)
-#define M_IF_NEEDED	MAS2_M
-#else
-#define M_IF_NEEDED	0
-#endif
 	mtspr	SPRN_MAS0,r9
 
 	lis	r9,(MAS1_VALID|MAS1_IPROT)@h
 	ori	r9,r9,(MAS1_TSIZE(BOOK3E_PAGESZ_1GB))@l
 	mtspr	SPRN_MAS1,r9
 
-	LOAD_REG_IMMEDIATE(r9, 0x0 | M_IF_NEEDED)
+	LOAD_REG_IMMEDIATE(r9, 0x0 | MAS2_M_IF_NEEDED)
 	mtspr	SPRN_MAS2,r9
 
 	LOAD_REG_IMMEDIATE(r9, 0x0 | MAS3_SR | MAS3_SW | MAS3_SX)
-- 
2.17.2


^ permalink raw reply related

* [PATCH v6 04/12] powerpc/fsl_booke/32: introduce create_tlb_entry() helper
From: Jason Yan @ 2019-08-09 10:07 UTC (permalink / raw)
  To: mpe, linuxppc-dev, diana.craciun, christophe.leroy, benh, paulus,
	npiggin, keescook, kernel-hardening
  Cc: wangkefeng.wang, Jason Yan, linux-kernel, jingxiangfeng,
	zhaohongjiang, thunder.leizhen, fanchengyang, yebin10
In-Reply-To: <20190809100800.5426-1-yanaijie@huawei.com>

Add a new helper create_tlb_entry() to create a tlb entry by the virtual
and physical address. This is a preparation to support boot kernel at a
randomized address.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Diana Craciun <diana.craciun@nxp.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
---
 arch/powerpc/kernel/head_fsl_booke.S | 29 ++++++++++++++++++++++++++++
 arch/powerpc/mm/mmu_decl.h           |  1 +
 2 files changed, 30 insertions(+)

diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index adf0505dbe02..04d124fee17d 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -1114,6 +1114,35 @@ __secondary_hold_acknowledge:
 	.long	-1
 #endif
 
+/*
+ * Create a 64M tlb by address and entry
+ * r3/r4 - physical address
+ * r5 - virtual address
+ * r6 - entry
+ */
+_GLOBAL(create_tlb_entry)
+	lis     r7,0x1000               /* Set MAS0(TLBSEL) = 1 */
+	rlwimi  r7,r6,16,4,15           /* Setup MAS0 = TLBSEL | ESEL(r6) */
+	mtspr   SPRN_MAS0,r7            /* Write MAS0 */
+
+	lis     r6,(MAS1_VALID|MAS1_IPROT)@h
+	ori     r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_64M))@l
+	mtspr   SPRN_MAS1,r6            /* Write MAS1 */
+
+	lis     r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@h
+	ori     r6,r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@l
+	and     r6,r6,r5
+	ori	r6,r6,MAS2_M@l
+	mtspr   SPRN_MAS2,r6            /* Write MAS2(EPN) */
+
+	ori     r8,r4,(MAS3_SW|MAS3_SR|MAS3_SX)
+	mtspr   SPRN_MAS3,r8            /* Write MAS3(RPN) */
+
+	tlbwe                           /* Write TLB */
+	isync
+	sync
+	blr
+
 /*
  * Create a tlb entry with the same effective and physical address as
  * the tlb entry used by the current running code. But set the TS to 1.
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index 32c1a191c28a..a09f89d3aa0f 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -142,6 +142,7 @@ extern unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
 extern void adjust_total_lowmem(void);
 extern int switch_to_as1(void);
 extern void restore_to_as0(int esel, int offset, void *dt_ptr, int bootcpu);
+void create_tlb_entry(phys_addr_t phys, unsigned long virt, int entry);
 #endif
 extern void loadcam_entry(unsigned int index);
 extern void loadcam_multi(int first_idx, int num, int tmp_idx);
-- 
2.17.2


^ permalink raw reply related

* [PATCH v6 07/12] powerpc/fsl_booke/32: randomize the kernel image offset
From: Jason Yan @ 2019-08-09 10:07 UTC (permalink / raw)
  To: mpe, linuxppc-dev, diana.craciun, christophe.leroy, benh, paulus,
	npiggin, keescook, kernel-hardening
  Cc: wangkefeng.wang, Jason Yan, linux-kernel, jingxiangfeng,
	zhaohongjiang, thunder.leizhen, fanchengyang, yebin10
In-Reply-To: <20190809100800.5426-1-yanaijie@huawei.com>

After we have the basic support of relocate the kernel in some
appropriate place, we can start to randomize the offset now.

Entropy is derived from the banner and timer, which will change every
build and boot. This not so much safe so additionally the bootloader may
pass entropy via the /chosen/kaslr-seed node in device tree.

We will use the first 512M of the low memory to randomize the kernel
image. The memory will be split in 64M zones. We will use the lower 8
bit of the entropy to decide the index of the 64M zone. Then we chose a
16K aligned offset inside the 64M zone to put the kernel in.

We also check if we will overlap with some areas like the dtb area, the
initrd area or the crashkernel area. If we cannot find a proper area,
kaslr will be disabled and boot from the original kernel.

Some pieces of code are derived from arch/x86/boot/compressed/kaslr.c or
arch/arm64/kernel/kaslr.c such as rotate_xor(). Credit goes to Kees and
Ard.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Diana Craciun <diana.craciun@nxp.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/kernel/kaslr_booke.c | 317 +++++++++++++++++++++++++++++-
 1 file changed, 315 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/kaslr_booke.c b/arch/powerpc/kernel/kaslr_booke.c
index f8dc60534ac1..51a0b3749724 100644
--- a/arch/powerpc/kernel/kaslr_booke.c
+++ b/arch/powerpc/kernel/kaslr_booke.c
@@ -12,15 +12,326 @@
 #include <linux/init.h>
 #include <linux/delay.h>
 #include <linux/memblock.h>
+#include <linux/libfdt.h>
+#include <linux/crash_core.h>
 #include <asm/pgalloc.h>
 #include <asm/prom.h>
+#include <asm/kdump.h>
 #include <mm/mmu_decl.h>
+#include <generated/compile.h>
+#include <generated/utsrelease.h>
+
+struct regions {
+	unsigned long pa_start;
+	unsigned long pa_end;
+	unsigned long kernel_size;
+	unsigned long dtb_start;
+	unsigned long dtb_end;
+	unsigned long initrd_start;
+	unsigned long initrd_end;
+	unsigned long crash_start;
+	unsigned long crash_end;
+	int reserved_mem;
+	int reserved_mem_addr_cells;
+	int reserved_mem_size_cells;
+};
+
+/* Simplified build-specific string for starting entropy. */
+static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@"
+		LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION;
+
+struct regions __initdata regions;
+
+static __init void kaslr_get_cmdline(void *fdt)
+{
+	int node = fdt_path_offset(fdt, "/chosen");
+
+	early_init_dt_scan_chosen(node, "chosen", 1, boot_command_line);
+}
+
+static unsigned long __init rotate_xor(unsigned long hash, const void *area,
+				       size_t size)
+{
+	size_t i;
+	const unsigned long *ptr = area;
+
+	for (i = 0; i < size / sizeof(hash); i++) {
+		/* Rotate by odd number of bits and XOR. */
+		hash = (hash << ((sizeof(hash) * 8) - 7)) | (hash >> 7);
+		hash ^= ptr[i];
+	}
+
+	return hash;
+}
+
+/* Attempt to create a simple starting entropy. This can make it defferent for
+ * every build but it is still not enough. Stronger entropy should
+ * be added to make it change for every boot.
+ */
+static unsigned long __init get_boot_seed(void *fdt)
+{
+	unsigned long hash = 0;
+
+	hash = rotate_xor(hash, build_str, sizeof(build_str));
+	hash = rotate_xor(hash, fdt, fdt_totalsize(fdt));
+
+	return hash;
+}
+
+static __init u64 get_kaslr_seed(void *fdt)
+{
+	int node, len;
+	fdt64_t *prop;
+	u64 ret;
+
+	node = fdt_path_offset(fdt, "/chosen");
+	if (node < 0)
+		return 0;
+
+	prop = fdt_getprop_w(fdt, node, "kaslr-seed", &len);
+	if (!prop || len != sizeof(u64))
+		return 0;
+
+	ret = fdt64_to_cpu(*prop);
+	*prop = 0;
+	return ret;
+}
+
+static __init bool regions_overlap(u32 s1, u32 e1, u32 s2, u32 e2)
+{
+	return e1 >= s2 && e2 >= s1;
+}
+
+static __init bool overlaps_reserved_region(const void *fdt, u32 start,
+					    u32 end)
+{
+	int subnode, len, i;
+	u64 base, size;
+
+	/* check for overlap with /memreserve/ entries */
+	for (i = 0; i < fdt_num_mem_rsv(fdt); i++) {
+		if (fdt_get_mem_rsv(fdt, i, &base, &size) < 0)
+			continue;
+		if (regions_overlap(start, end, base, base + size))
+			return true;
+	}
+
+	if (regions.reserved_mem < 0)
+		return false;
+
+	/* check for overlap with static reservations in /reserved-memory */
+	for (subnode = fdt_first_subnode(fdt, regions.reserved_mem);
+	     subnode >= 0;
+	     subnode = fdt_next_subnode(fdt, subnode)) {
+		const fdt32_t *reg;
+		u64 rsv_end;
+
+		len = 0;
+		reg = fdt_getprop(fdt, subnode, "reg", &len);
+		while (len >= (regions.reserved_mem_addr_cells +
+			       regions.reserved_mem_size_cells)) {
+			base = fdt32_to_cpu(reg[0]);
+			if (regions.reserved_mem_addr_cells == 2)
+				base = (base << 32) | fdt32_to_cpu(reg[1]);
+
+			reg += regions.reserved_mem_addr_cells;
+			len -= 4 * regions.reserved_mem_addr_cells;
+
+			size = fdt32_to_cpu(reg[0]);
+			if (regions.reserved_mem_size_cells == 2)
+				size = (size << 32) | fdt32_to_cpu(reg[1]);
+
+			reg += regions.reserved_mem_size_cells;
+			len -= 4 * regions.reserved_mem_size_cells;
+
+			if (base >= regions.pa_end)
+				continue;
+
+			rsv_end = min(base + size, (u64)U32_MAX);
+
+			if (regions_overlap(start, end, base, rsv_end))
+				return true;
+		}
+	}
+	return false;
+}
+
+static __init bool overlaps_region(const void *fdt, u32 start,
+				   u32 end)
+{
+	if (regions_overlap(start, end, regions.dtb_start,
+			    regions.dtb_end))
+		return true;
+
+	if (regions_overlap(start, end, regions.initrd_start,
+			    regions.initrd_end))
+		return true;
+
+	if (regions_overlap(start, end, regions.crash_start,
+			    regions.crash_end))
+		return true;
+
+	return overlaps_reserved_region(fdt, start, end);
+}
+
+static void __init get_crash_kernel(void *fdt, unsigned long size)
+{
+#ifdef CONFIG_CRASH_CORE
+	unsigned long long crash_size, crash_base;
+	int ret;
+
+	ret = parse_crashkernel(boot_command_line, size, &crash_size,
+				&crash_base);
+	if (ret != 0 || crash_size == 0)
+		return;
+	if (crash_base == 0)
+		crash_base = KDUMP_KERNELBASE;
+
+	regions.crash_start = (unsigned long)crash_base;
+	regions.crash_end = (unsigned long)(crash_base + crash_size);
+
+	pr_debug("crash_base=0x%llx crash_size=0x%llx\n", crash_base, crash_size);
+#endif
+}
+
+static void __init get_initrd_range(void *fdt)
+{
+	u64 start, end;
+	int node, len;
+	const __be32 *prop;
+
+	node = fdt_path_offset(fdt, "/chosen");
+	if (node < 0)
+		return;
+
+	prop = fdt_getprop(fdt, node, "linux,initrd-start", &len);
+	if (!prop)
+		return;
+	start = of_read_number(prop, len / 4);
+
+	prop = fdt_getprop(fdt, node, "linux,initrd-end", &len);
+	if (!prop)
+		return;
+	end = of_read_number(prop, len / 4);
+
+	regions.initrd_start = (unsigned long)start;
+	regions.initrd_end = (unsigned long)end;
+
+	pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n", start, end);
+}
+
+static __init unsigned long get_usable_offset(const void *fdt,
+					      unsigned long start)
+{
+	unsigned long pa;
+	unsigned long pa_end;
+
+	for (pa = start; pa > regions.pa_start; pa -= SZ_16K) {
+		pa_end = pa + regions.kernel_size;
+		if (overlaps_region(fdt, pa, pa_end))
+			continue;
+
+		return pa;
+	}
+	return 0;
+}
+
+static __init void get_cell_sizes(const void *fdt, int node, int *addr_cells,
+				  int *size_cells)
+{
+	const int *prop;
+	int len;
+
+	/*
+	 * Retrieve the #address-cells and #size-cells properties
+	 * from the 'node', or use the default if not provided.
+	 */
+	*addr_cells = *size_cells = 1;
+
+	prop = fdt_getprop(fdt, node, "#address-cells", &len);
+	if (len == 4)
+		*addr_cells = fdt32_to_cpu(*prop);
+	prop = fdt_getprop(fdt, node, "#size-cells", &len);
+	if (len == 4)
+		*size_cells = fdt32_to_cpu(*prop);
+}
 
 static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size,
 						  unsigned long kernel_sz)
 {
-	/* return a fixed offset of 64M for now */
-	return SZ_64M;
+	unsigned long offset, random;
+	unsigned long ram, linear_sz;
+	unsigned long kaslr_offset;
+	u64 seed;
+	unsigned long index;
+
+	random = get_boot_seed(dt_ptr);
+
+	seed = get_tb() << 32;
+	seed ^= get_tb();
+	random = rotate_xor(random, &seed, sizeof(seed));
+
+	/*
+	 * Retrieve (and wipe) the seed from the FDT
+	 */
+	seed = get_kaslr_seed(dt_ptr);
+	if (seed)
+		random = rotate_xor(random, &seed, sizeof(seed));
+
+	ram = min_t(phys_addr_t, __max_low_memory, size);
+	ram = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, true);
+	linear_sz = min_t(unsigned long, ram, SZ_512M);
+
+	/* If the linear size is smaller than 64M, do not randmize */
+	if (linear_sz < SZ_64M)
+		return 0;
+
+	/* check for a reserved-memory node and record its cell sizes */
+	regions.reserved_mem = fdt_path_offset(dt_ptr, "/reserved-memory");
+	if (regions.reserved_mem >= 0)
+		get_cell_sizes(dt_ptr, regions.reserved_mem,
+			       &regions.reserved_mem_addr_cells,
+			       &regions.reserved_mem_size_cells);
+
+	regions.pa_start = 0;
+	regions.pa_end = linear_sz;
+	regions.dtb_start = __pa(dt_ptr);
+	regions.dtb_end = __pa(dt_ptr) + fdt_totalsize(dt_ptr);
+	regions.kernel_size = kernel_sz;
+
+	get_initrd_range(dt_ptr);
+	get_crash_kernel(dt_ptr, ram);
+
+	/*
+	 * Decide which 64M we want to start
+	 * Only use the low 8 bits of the random seed
+	 */
+	index = random & 0xFF;
+	index %= linear_sz / SZ_64M;
+
+	/* Decide offset inside 64M */
+	if (index == 0) {
+		offset = random % (SZ_64M - round_up(kernel_sz, SZ_16K) * 2);
+		offset += round_up(kernel_sz, SZ_16K);
+		offset = round_up(offset, SZ_16K);
+	} else {
+		offset = random % (SZ_64M - kernel_sz);
+		offset = round_down(offset, SZ_16K);
+	}
+
+	while (index >= 0) {
+		offset = offset + index * SZ_64M;
+		kaslr_offset = get_usable_offset(dt_ptr, offset);
+		if (kaslr_offset)
+			break;
+		index--;
+	}
+
+	/* Did not find any usable region? Give up randomize */
+	if (index < 0)
+		kaslr_offset = 0;
+
+	return kaslr_offset;
 }
 
 /*
@@ -37,6 +348,8 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size)
 
 	kernel_sz = (unsigned long)_end - KERNELBASE;
 
+	kaslr_get_cmdline(dt_ptr);
+
 	offset = kaslr_choose_location(dt_ptr, size, kernel_sz);
 
 	if (offset == 0)
-- 
2.17.2


^ permalink raw reply related

* [PATCH v6 05/12] powerpc/fsl_booke/32: introduce reloc_kernel_entry() helper
From: Jason Yan @ 2019-08-09 10:07 UTC (permalink / raw)
  To: mpe, linuxppc-dev, diana.craciun, christophe.leroy, benh, paulus,
	npiggin, keescook, kernel-hardening
  Cc: wangkefeng.wang, Jason Yan, linux-kernel, jingxiangfeng,
	zhaohongjiang, thunder.leizhen, fanchengyang, yebin10
In-Reply-To: <20190809100800.5426-1-yanaijie@huawei.com>

Add a new helper reloc_kernel_entry() to jump back to the start of the
new kernel. After we put the new kernel in a randomized place we can use
this new helper to enter the kernel and begin to relocate again.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Diana Craciun <diana.craciun@nxp.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
---
 arch/powerpc/kernel/head_fsl_booke.S | 13 +++++++++++++
 arch/powerpc/mm/mmu_decl.h           |  1 +
 2 files changed, 14 insertions(+)

diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 04d124fee17d..2083382dd662 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -1143,6 +1143,19 @@ _GLOBAL(create_tlb_entry)
 	sync
 	blr
 
+/*
+ * Return to the start of the relocated kernel and run again
+ * r3 - virtual address of fdt
+ * r4 - entry of the kernel
+ */
+_GLOBAL(reloc_kernel_entry)
+	mfmsr	r7
+	rlwinm	r7, r7, 0, ~(MSR_IS | MSR_DS)
+
+	mtspr	SPRN_SRR0,r4
+	mtspr	SPRN_SRR1,r7
+	rfi
+
 /*
  * Create a tlb entry with the same effective and physical address as
  * the tlb entry used by the current running code. But set the TS to 1.
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index a09f89d3aa0f..804da298beb3 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -143,6 +143,7 @@ extern void adjust_total_lowmem(void);
 extern int switch_to_as1(void);
 extern void restore_to_as0(int esel, int offset, void *dt_ptr, int bootcpu);
 void create_tlb_entry(phys_addr_t phys, unsigned long virt, int entry);
+void reloc_kernel_entry(void *fdt, int addr);
 #endif
 extern void loadcam_entry(unsigned int index);
 extern void loadcam_multi(int first_idx, int num, int tmp_idx);
-- 
2.17.2


^ permalink raw reply related

* [PATCH v6 10/12] powerpc/fsl_booke/kaslr: dump out kernel offset information on panic
From: Jason Yan @ 2019-08-09 10:07 UTC (permalink / raw)
  To: mpe, linuxppc-dev, diana.craciun, christophe.leroy, benh, paulus,
	npiggin, keescook, kernel-hardening
  Cc: wangkefeng.wang, Jason Yan, linux-kernel, jingxiangfeng,
	zhaohongjiang, thunder.leizhen, fanchengyang, yebin10
In-Reply-To: <20190809100800.5426-1-yanaijie@huawei.com>

When kaslr is enabled, the kernel offset is different for every boot.
This brings some difficult to debug the kernel. Dump out the kernel
offset when panic so that we can easily debug the kernel.

This code is derived from x86/arm64 which has similar functionality.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Diana Craciun <diana.craciun@nxp.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
---
 arch/powerpc/include/asm/page.h    |  5 +++++
 arch/powerpc/kernel/setup-common.c | 20 ++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 4d32d1b561d6..b34b9cdd91f1 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -317,6 +317,11 @@ struct vm_area_struct;
 
 extern unsigned long kernstart_virt_addr;
 
+static inline unsigned long kaslr_offset(void)
+{
+	return kernstart_virt_addr - KERNELBASE;
+}
+
 #include <asm-generic/memory_model.h>
 #endif /* __ASSEMBLY__ */
 #include <asm/slice.h>
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 1f8db666468d..ba1a34ab218a 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -715,8 +715,28 @@ static struct notifier_block ppc_panic_block = {
 	.priority = INT_MIN /* may not return; must be done last */
 };
 
+/*
+ * Dump out kernel offset information on panic.
+ */
+static int dump_kernel_offset(struct notifier_block *self, unsigned long v,
+			      void *p)
+{
+	pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
+		 kaslr_offset(), KERNELBASE);
+
+	return 0;
+}
+
+static struct notifier_block kernel_offset_notifier = {
+	.notifier_call = dump_kernel_offset
+};
+
 void __init setup_panic(void)
 {
+	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset() > 0)
+		atomic_notifier_chain_register(&panic_notifier_list,
+					       &kernel_offset_notifier);
+
 	/* PPC64 always does a hard irq disable in its panic handler */
 	if (!IS_ENABLED(CONFIG_PPC64) && !ppc_md.panic)
 		return;
-- 
2.17.2


^ permalink raw reply related

* [PATCH v6 06/12] powerpc/fsl_booke/32: implement KASLR infrastructure
From: Jason Yan @ 2019-08-09 10:07 UTC (permalink / raw)
  To: mpe, linuxppc-dev, diana.craciun, christophe.leroy, benh, paulus,
	npiggin, keescook, kernel-hardening
  Cc: wangkefeng.wang, Jason Yan, linux-kernel, jingxiangfeng,
	zhaohongjiang, thunder.leizhen, fanchengyang, yebin10
In-Reply-To: <20190809100800.5426-1-yanaijie@huawei.com>

This patch add support to boot kernel from places other than KERNELBASE.
Since CONFIG_RELOCATABLE has already supported, what we need to do is
map or copy kernel to a proper place and relocate. Freescale Book-E
parts expect lowmem to be mapped by fixed TLB entries(TLB1). The TLB1
entries are not suitable to map the kernel directly in a randomized
region, so we chose to copy the kernel to a proper place and restart to
relocate.

The offset of the kernel was not randomized yet(a fixed 64M is set). We
will randomize it in the next patch.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Diana Craciun <diana.craciun@nxp.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/Kconfig                          | 11 ++++
 arch/powerpc/kernel/Makefile                  |  1 +
 arch/powerpc/kernel/early_32.c                |  2 +-
 arch/powerpc/kernel/fsl_booke_entry_mapping.S | 17 +++--
 arch/powerpc/kernel/head_fsl_booke.S          | 13 +++-
 arch/powerpc/kernel/kaslr_booke.c             | 62 +++++++++++++++++++
 arch/powerpc/mm/mmu_decl.h                    |  7 +++
 arch/powerpc/mm/nohash/fsl_booke.c            |  7 ++-
 8 files changed, 105 insertions(+), 15 deletions(-)
 create mode 100644 arch/powerpc/kernel/kaslr_booke.c

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 77f6ebf97113..710c12ef7159 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -548,6 +548,17 @@ config RELOCATABLE
 	  setting can still be useful to bootwrappers that need to know the
 	  load address of the kernel (eg. u-boot/mkimage).
 
+config RANDOMIZE_BASE
+	bool "Randomize the address of the kernel image"
+	depends on (FSL_BOOKE && FLATMEM && PPC32)
+	depends on RELOCATABLE
+	help
+	  Randomizes the virtual address at which the kernel image is
+	  loaded, as a security feature that deters exploit attempts
+	  relying on knowledge of the location of kernel internals.
+
+	  If unsure, say N.
+
 config RELOCATABLE_TEST
 	bool "Test relocatable kernel"
 	depends on (PPC64 && RELOCATABLE)
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index ea0c69236789..32f6c5b99307 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -106,6 +106,7 @@ extra-$(CONFIG_PPC_8xx)		:= head_8xx.o
 extra-y				+= vmlinux.lds
 
 obj-$(CONFIG_RELOCATABLE)	+= reloc_$(BITS).o
+obj-$(CONFIG_RANDOMIZE_BASE)	+= kaslr_booke.o
 
 obj-$(CONFIG_PPC32)		+= entry_32.o setup_32.o early_32.o
 obj-$(CONFIG_PPC64)		+= dma-iommu.o iommu.o
diff --git a/arch/powerpc/kernel/early_32.c b/arch/powerpc/kernel/early_32.c
index 3482118ffe76..0c5849fd936d 100644
--- a/arch/powerpc/kernel/early_32.c
+++ b/arch/powerpc/kernel/early_32.c
@@ -32,5 +32,5 @@ notrace unsigned long __init early_init(unsigned long dt_ptr)
 
 	apply_feature_fixups();
 
-	return KERNELBASE + offset;
+	return kernstart_virt_addr + offset;
 }
diff --git a/arch/powerpc/kernel/fsl_booke_entry_mapping.S b/arch/powerpc/kernel/fsl_booke_entry_mapping.S
index f4d3eaae54a9..641920d4f694 100644
--- a/arch/powerpc/kernel/fsl_booke_entry_mapping.S
+++ b/arch/powerpc/kernel/fsl_booke_entry_mapping.S
@@ -155,23 +155,22 @@ skpinv:	addi	r6,r6,1				/* Increment */
 
 #if defined(ENTRY_MAPPING_BOOT_SETUP)
 
-/* 6. Setup KERNELBASE mapping in TLB1[0] */
+/* 6. Setup kernstart_virt_addr mapping in TLB1[0] */
 	lis	r6,0x1000		/* Set MAS0(TLBSEL) = TLB1(1), ESEL = 0 */
 	mtspr	SPRN_MAS0,r6
 	lis	r6,(MAS1_VALID|MAS1_IPROT)@h
 	ori	r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_64M))@l
 	mtspr	SPRN_MAS1,r6
-	lis	r6,MAS2_VAL(PAGE_OFFSET, BOOK3E_PAGESZ_64M, MAS2_M_IF_NEEDED)@h
-	ori	r6,r6,MAS2_VAL(PAGE_OFFSET, BOOK3E_PAGESZ_64M, MAS2_M_IF_NEEDED)@l
-	mtspr	SPRN_MAS2,r6
+	lis     r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@h
+	ori     r6,r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@l
+	and     r6,r6,r20
+	ori	r6,r6,MAS2_M_IF_NEEDED@l
+	mtspr   SPRN_MAS2,r6
 	mtspr	SPRN_MAS3,r8
 	tlbwe
 
-/* 7. Jump to KERNELBASE mapping */
-	lis	r6,(KERNELBASE & ~0xfff)@h
-	ori	r6,r6,(KERNELBASE & ~0xfff)@l
-	rlwinm	r7,r25,0,0x03ffffff
-	add	r6,r7,r6
+/* 7. Jump to kernstart_virt_addr mapping */
+	mr	r6,r20
 
 #elif defined(ENTRY_MAPPING_KEXEC_SETUP)
 /*
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 2083382dd662..f7a5c5f03c72 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -155,6 +155,8 @@ _ENTRY(_start);
  */
 
 _ENTRY(__early_start)
+	LOAD_REG_ADDR_PIC(r20, kernstart_virt_addr)
+	lwz     r20,0(r20)
 
 #define ENTRY_MAPPING_BOOT_SETUP
 #include "fsl_booke_entry_mapping.S"
@@ -277,8 +279,8 @@ set_ivor:
 	ori	r6, r6, swapper_pg_dir@l
 	lis	r5, abatron_pteptrs@h
 	ori	r5, r5, abatron_pteptrs@l
-	lis	r4, KERNELBASE@h
-	ori	r4, r4, KERNELBASE@l
+	lis     r3, kernstart_virt_addr@ha
+	lwz     r4, kernstart_virt_addr@l(r3)
 	stw	r5, 0(r4)	/* Save abatron_pteptrs at a fixed location */
 	stw	r6, 0(r5)
 
@@ -1067,7 +1069,12 @@ __secondary_start:
 	mr	r5,r25		/* phys kernel start */
 	rlwinm	r5,r5,0,~0x3ffffff	/* aligned 64M */
 	subf	r4,r5,r4	/* memstart_addr - phys kernel start */
-	li	r5,0		/* no device tree */
+	lis	r7,KERNELBASE@h
+	ori	r7,r7,KERNELBASE@l
+	cmpw	r20,r7		/* if kimage_vaddr != KERNELBASE, randomized */
+	beq	2f
+	li	r4,0
+2:	li	r5,0		/* no device tree */
 	li	r6,0		/* not boot cpu */
 	bl	restore_to_as0
 
diff --git a/arch/powerpc/kernel/kaslr_booke.c b/arch/powerpc/kernel/kaslr_booke.c
new file mode 100644
index 000000000000..f8dc60534ac1
--- /dev/null
+++ b/arch/powerpc/kernel/kaslr_booke.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// Copyright (C) 2019 Jason Yan <yanaijie@huawei.com>
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/stddef.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/memblock.h>
+#include <asm/pgalloc.h>
+#include <asm/prom.h>
+#include <mm/mmu_decl.h>
+
+static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size,
+						  unsigned long kernel_sz)
+{
+	/* return a fixed offset of 64M for now */
+	return SZ_64M;
+}
+
+/*
+ * To see if we need to relocate the kernel to a random offset
+ * void *dt_ptr - address of the device tree
+ * phys_addr_t size - size of the first memory block
+ */
+notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size)
+{
+	unsigned long tlb_virt;
+	phys_addr_t tlb_phys;
+	unsigned long offset;
+	unsigned long kernel_sz;
+
+	kernel_sz = (unsigned long)_end - KERNELBASE;
+
+	offset = kaslr_choose_location(dt_ptr, size, kernel_sz);
+
+	if (offset == 0)
+		return;
+
+	kernstart_virt_addr += offset;
+	kernstart_addr += offset;
+
+	is_second_reloc = 1;
+
+	if (offset >= SZ_64M) {
+		tlb_virt = round_down(kernstart_virt_addr, SZ_64M);
+		tlb_phys = round_down(kernstart_addr, SZ_64M);
+
+		/* Create kernel map to relocate in */
+		create_tlb_entry(tlb_phys, tlb_virt, 1);
+	}
+
+	/* Copy the kernel to it's new location and run */
+	memcpy((void *)kernstart_virt_addr, (void *)KERNELBASE, kernel_sz);
+
+	reloc_kernel_entry(dt_ptr, kernstart_virt_addr);
+}
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index 804da298beb3..213997d69729 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -144,10 +144,17 @@ extern int switch_to_as1(void);
 extern void restore_to_as0(int esel, int offset, void *dt_ptr, int bootcpu);
 void create_tlb_entry(phys_addr_t phys, unsigned long virt, int entry);
 void reloc_kernel_entry(void *fdt, int addr);
+extern int is_second_reloc;
 #endif
 extern void loadcam_entry(unsigned int index);
 extern void loadcam_multi(int first_idx, int num, int tmp_idx);
 
+#ifdef CONFIG_RANDOMIZE_BASE
+void kaslr_early_init(void *dt_ptr, phys_addr_t size);
+#else
+static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {}
+#endif
+
 struct tlbcam {
 	u32	MAS0;
 	u32	MAS1;
diff --git a/arch/powerpc/mm/nohash/fsl_booke.c b/arch/powerpc/mm/nohash/fsl_booke.c
index 556e3cd52a35..2dc27cf88add 100644
--- a/arch/powerpc/mm/nohash/fsl_booke.c
+++ b/arch/powerpc/mm/nohash/fsl_booke.c
@@ -263,7 +263,8 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 int __initdata is_second_reloc;
 notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
 {
-	unsigned long base = KERNELBASE;
+	unsigned long base = kernstart_virt_addr;
+	phys_addr_t size;
 
 	kernstart_addr = start;
 	if (is_second_reloc) {
@@ -291,7 +292,7 @@ notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
 	start &= ~0x3ffffff;
 	base &= ~0x3ffffff;
 	virt_phys_offset = base - start;
-	early_get_first_memblock_info(__va(dt_ptr), NULL);
+	early_get_first_memblock_info(__va(dt_ptr), &size);
 	/*
 	 * We now get the memstart_addr, then we should check if this
 	 * address is the same as what the PAGE_OFFSET map to now. If
@@ -316,6 +317,8 @@ notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
 		/* We should never reach here */
 		panic("Relocation error");
 	}
+
+	kaslr_early_init(__va(dt_ptr), size);
 }
 #endif
 #endif
-- 
2.17.2


^ permalink raw reply related

* [PATCH v6 08/12] powerpc/fsl_booke/kaslr: clear the original kernel if randomized
From: Jason Yan @ 2019-08-09 10:07 UTC (permalink / raw)
  To: mpe, linuxppc-dev, diana.craciun, christophe.leroy, benh, paulus,
	npiggin, keescook, kernel-hardening
  Cc: wangkefeng.wang, Jason Yan, linux-kernel, jingxiangfeng,
	zhaohongjiang, thunder.leizhen, fanchengyang, yebin10
In-Reply-To: <20190809100800.5426-1-yanaijie@huawei.com>

The original kernel still exists in the memory, clear it now.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Diana Craciun <diana.craciun@nxp.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
---
 arch/powerpc/kernel/kaslr_booke.c  | 11 +++++++++++
 arch/powerpc/mm/mmu_decl.h         |  2 ++
 arch/powerpc/mm/nohash/fsl_booke.c |  1 +
 3 files changed, 14 insertions(+)

diff --git a/arch/powerpc/kernel/kaslr_booke.c b/arch/powerpc/kernel/kaslr_booke.c
index 51a0b3749724..9a360b6124ed 100644
--- a/arch/powerpc/kernel/kaslr_booke.c
+++ b/arch/powerpc/kernel/kaslr_booke.c
@@ -373,3 +373,14 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size)
 
 	reloc_kernel_entry(dt_ptr, kernstart_virt_addr);
 }
+
+void __init kaslr_late_init(void)
+{
+	/* If randomized, clear the original kernel */
+	if (kernstart_virt_addr != KERNELBASE) {
+		unsigned long kernel_sz;
+
+		kernel_sz = (unsigned long)_end - kernstart_virt_addr;
+		memzero_explicit((void *)KERNELBASE, kernel_sz);
+	}
+}
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index 213997d69729..64b2ac8a5343 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -151,8 +151,10 @@ extern void loadcam_multi(int first_idx, int num, int tmp_idx);
 
 #ifdef CONFIG_RANDOMIZE_BASE
 void kaslr_early_init(void *dt_ptr, phys_addr_t size);
+void kaslr_late_init(void);
 #else
 static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {}
+static inline void kaslr_late_init(void) {}
 #endif
 
 struct tlbcam {
diff --git a/arch/powerpc/mm/nohash/fsl_booke.c b/arch/powerpc/mm/nohash/fsl_booke.c
index 2dc27cf88add..b4eb06ceb189 100644
--- a/arch/powerpc/mm/nohash/fsl_booke.c
+++ b/arch/powerpc/mm/nohash/fsl_booke.c
@@ -269,6 +269,7 @@ notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start)
 	kernstart_addr = start;
 	if (is_second_reloc) {
 		virt_phys_offset = PAGE_OFFSET - memstart_addr;
+		kaslr_late_init();
 		return;
 	}
 
-- 
2.17.2


^ permalink raw reply related

* [PATCH v6 09/12] powerpc/fsl_booke/kaslr: support nokaslr cmdline parameter
From: Jason Yan @ 2019-08-09 10:07 UTC (permalink / raw)
  To: mpe, linuxppc-dev, diana.craciun, christophe.leroy, benh, paulus,
	npiggin, keescook, kernel-hardening
  Cc: wangkefeng.wang, Jason Yan, linux-kernel, jingxiangfeng,
	zhaohongjiang, thunder.leizhen, fanchengyang, yebin10
In-Reply-To: <20190809100800.5426-1-yanaijie@huawei.com>

One may want to disable kaslr when boot, so provide a cmdline parameter
'nokaslr' to support this.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Diana Craciun <diana.craciun@nxp.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/kernel/kaslr_booke.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/powerpc/kernel/kaslr_booke.c b/arch/powerpc/kernel/kaslr_booke.c
index 9a360b6124ed..fd32ae10c218 100644
--- a/arch/powerpc/kernel/kaslr_booke.c
+++ b/arch/powerpc/kernel/kaslr_booke.c
@@ -334,6 +334,11 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size
 	return kaslr_offset;
 }
 
+static inline __init bool kaslr_disabled(void)
+{
+	return strstr(boot_command_line, "nokaslr") != NULL;
+}
+
 /*
  * To see if we need to relocate the kernel to a random offset
  * void *dt_ptr - address of the device tree
@@ -349,6 +354,8 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size)
 	kernel_sz = (unsigned long)_end - KERNELBASE;
 
 	kaslr_get_cmdline(dt_ptr);
+	if (kaslr_disabled())
+		return;
 
 	offset = kaslr_choose_location(dt_ptr, size, kernel_sz);
 
-- 
2.17.2


^ permalink raw reply related

* [PATCH v6 12/12] powerpc/fsl_booke/32: Document KASLR implementation
From: Jason Yan @ 2019-08-09 10:08 UTC (permalink / raw)
  To: mpe, linuxppc-dev, diana.craciun, christophe.leroy, benh, paulus,
	npiggin, keescook, kernel-hardening
  Cc: wangkefeng.wang, Jason Yan, linux-kernel, jingxiangfeng,
	zhaohongjiang, thunder.leizhen, fanchengyang, yebin10
In-Reply-To: <20190809100800.5426-1-yanaijie@huawei.com>

Add document to explain how we implement KASLR for fsl_booke32.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Diana Craciun <diana.craciun@nxp.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
---
 Documentation/powerpc/kaslr-booke32.rst | 42 +++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 Documentation/powerpc/kaslr-booke32.rst

diff --git a/Documentation/powerpc/kaslr-booke32.rst b/Documentation/powerpc/kaslr-booke32.rst
new file mode 100644
index 000000000000..8b259fdfdf03
--- /dev/null
+++ b/Documentation/powerpc/kaslr-booke32.rst
@@ -0,0 +1,42 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===========================
+KASLR for Freescale BookE32
+===========================
+
+The word KASLR stands for Kernel Address Space Layout Randomization.
+
+This document tries to explain the implementation of the KASLR for
+Freescale BookE32. KASLR is a security feature that deters exploit
+attempts relying on knowledge of the location of kernel internals.
+
+Since CONFIG_RELOCATABLE has already supported, what we need to do is
+map or copy kernel to a proper place and relocate. Freescale Book-E
+parts expect lowmem to be mapped by fixed TLB entries(TLB1). The TLB1
+entries are not suitable to map the kernel directly in a randomized
+region, so we chose to copy the kernel to a proper place and restart to
+relocate.
+
+Entropy is derived from the banner and timer base, which will change every
+build and boot. This not so much safe so additionally the bootloader may
+pass entropy via the /chosen/kaslr-seed node in device tree.
+
+We will use the first 512M of the low memory to randomize the kernel
+image. The memory will be split in 64M zones. We will use the lower 8
+bit of the entropy to decide the index of the 64M zone. Then we chose a
+16K aligned offset inside the 64M zone to put the kernel in::
+
+    KERNELBASE
+
+        |-->   64M   <--|
+        |               |
+        +---------------+    +----------------+---------------+
+        |               |....|    |kernel|    |               |
+        +---------------+    +----------------+---------------+
+        |                         |
+        |----->   offset    <-----|
+
+                              kernstart_virt_addr
+
+To enable KASLR, set CONFIG_RANDOMIZE_BASE = y. If KASLR is enable and you
+want to disable it at runtime, add "nokaslr" to the kernel cmdline.
-- 
2.17.2


^ permalink raw reply related

* [PATCH v6 11/12] powerpc/fsl_booke/kaslr: export offset in VMCOREINFO ELF notes
From: Jason Yan @ 2019-08-09 10:07 UTC (permalink / raw)
  To: mpe, linuxppc-dev, diana.craciun, christophe.leroy, benh, paulus,
	npiggin, keescook, kernel-hardening
  Cc: wangkefeng.wang, Jason Yan, linux-kernel, jingxiangfeng,
	zhaohongjiang, thunder.leizhen, fanchengyang, yebin10
In-Reply-To: <20190809100800.5426-1-yanaijie@huawei.com>

Like all other architectures such as x86 or arm64, include KASLR offset
in VMCOREINFO ELF notes to assist in debugging. After this, we can use
crash --kaslr option to parse vmcore generated from a kaslr kernel.

Note: The crash tool needs to support --kaslr too.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Cc: Diana Craciun <diana.craciun@nxp.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
---
 arch/powerpc/kernel/machine_kexec.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c
index c4ed328a7b96..078fe3d76feb 100644
--- a/arch/powerpc/kernel/machine_kexec.c
+++ b/arch/powerpc/kernel/machine_kexec.c
@@ -86,6 +86,7 @@ void arch_crash_save_vmcoreinfo(void)
 	VMCOREINFO_STRUCT_SIZE(mmu_psize_def);
 	VMCOREINFO_OFFSET(mmu_psize_def, shift);
 #endif
+	vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
 }
 
 /*
-- 
2.17.2


^ permalink raw reply related

* Re: [RFC V2 0/1] mm/debug: Add tests for architecture exported page table helpers
From: Matthew Wilcox @ 2019-08-09 10:16 UTC (permalink / raw)
  To: Anshuman Khandual
  Cc: Mark Rutland, linux-ia64, linux-sh, Peter Zijlstra, James Hogan,
	Tetsuo Handa, Heiko Carstens, Michal Hocko, linux-mm, Dave Hansen,
	Paul Mackerras, sparclinux, Thomas Gleixner, linux-s390, x86,
	Russell King - ARM Linux, Steven Price, Jason Gunthorpe,
	linux-arm-kernel, linux-snps-arc, Kees Cook, Masahiro Yamada,
	Mark Brown, Dan Williams, Vlastimil Babka, Sri Krishna chowdary,
	Ard Biesheuvel, Greg Kroah-Hartman, linux-mips, Ralf Baechle,
	linux-kernel, Paul Burton, Mike Rapoport, Vineet Gupta,
	Martin Schwidefsky, Andrew Morton, linuxppc-dev, David S. Miller
In-Reply-To: <1565335998-22553-1-git-send-email-anshuman.khandual@arm.com>

On Fri, Aug 09, 2019 at 01:03:17PM +0530, Anshuman Khandual wrote:
> Should alloc_gigantic_page() be made available as an interface for general
> use in the kernel. The test module here uses very similar implementation from
> HugeTLB to allocate a PUD aligned memory block. Similar for mm_alloc() which
> needs to be exported through a header.

Why are you allocating memory at all instead of just using some
known-to-exist PFNs like I suggested?

^ permalink raw reply

* Re: [RFC V2 0/1] mm/debug: Add tests for architecture exported page table helpers
From: Anshuman Khandual @ 2019-08-09 10:35 UTC (permalink / raw)
  To: Matthew Wilcox
  Cc: Mark Rutland, linux-ia64, linux-sh, Peter Zijlstra, James Hogan,
	Tetsuo Handa, Heiko Carstens, Michal Hocko, linux-mm, Dave Hansen,
	Paul Mackerras, sparclinux, Thomas Gleixner, linux-s390, x86,
	Russell King - ARM Linux, Steven Price, Jason Gunthorpe,
	linux-arm-kernel, linux-snps-arc, Kees Cook, Masahiro Yamada,
	Mark Brown, Dan Williams, Vlastimil Babka, Sri Krishna chowdary,
	Ard Biesheuvel, Greg Kroah-Hartman, linux-mips, Ralf Baechle,
	linux-kernel, Paul Burton, Mike Rapoport, Vineet Gupta,
	Martin Schwidefsky, Andrew Morton, linuxppc-dev, David S. Miller
In-Reply-To: <20190809101632.GM5482@bombadil.infradead.org>



On 08/09/2019 03:46 PM, Matthew Wilcox wrote:
> On Fri, Aug 09, 2019 at 01:03:17PM +0530, Anshuman Khandual wrote:
>> Should alloc_gigantic_page() be made available as an interface for general
>> use in the kernel. The test module here uses very similar implementation from
>> HugeTLB to allocate a PUD aligned memory block. Similar for mm_alloc() which
>> needs to be exported through a header.
> 
> Why are you allocating memory at all instead of just using some
> known-to-exist PFNs like I suggested?

We needed PFN to be PUD aligned for pfn_pud() and PMD aligned for mk_pmd().
Now walking the kernel page table for a known symbol like kernel_init()
as you had suggested earlier we might encounter page table page entries at PMD
and PUD which might not be PMD or PUD aligned respectively. It seemed to me
that alignment requirement is applicable only for mk_pmd() and pfn_pud()
which create large mappings at those levels but that requirement does not
exist for page table pages pointing to next level. Is not that correct ? Or
I am missing something here ?

^ permalink raw reply

* [Bug 204479] KASAN hit at modprobe zram
From: bugzilla-daemon @ 2019-08-09 10:44 UTC (permalink / raw)
  To: linuxppc-dev
In-Reply-To: <bug-204479-206035@https.bugzilla.kernel.org/>

https://bugzilla.kernel.org/show_bug.cgi?id=204479

--- Comment #10 from Erhard F. (erhard_f@mailbox.org) ---
Created attachment 284297
  --> https://bugzilla.kernel.org/attachment.cgi?id=284297&action=edit
dmesg (kernel 5.3-rc3 + patch, without CONFIG_SMP, PowerMac G4 DP)

Here's the dmesg with the kernel built without CONFIG_SMP.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

^ permalink raw reply

* [PATCH 2/2] ASoC: fsl_esai: Add new compatible string for imx6ull
From: Shengjiu Wang @ 2019-08-09 10:27 UTC (permalink / raw)
  To: timur, nicoleotsuka, Xiubo.Lee, festevam, broonie, alsa-devel,
	robh+dt, mark.rutland
  Cc: devicetree, linuxppc-dev, linux-kernel
In-Reply-To: <1565346467-5769-1-git-send-email-shengjiu.wang@nxp.com>

Add new compatible string "fsl,imx6ull-esai" in the binding document.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 Documentation/devicetree/bindings/sound/fsl,esai.txt | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/sound/fsl,esai.txt b/Documentation/devicetree/bindings/sound/fsl,esai.txt
index 5b9914367610..0e6e2166f76c 100644
--- a/Documentation/devicetree/bindings/sound/fsl,esai.txt
+++ b/Documentation/devicetree/bindings/sound/fsl,esai.txt
@@ -7,8 +7,11 @@ other DSPs. It has up to six transmitters and four receivers.
 
 Required properties:
 
-  - compatible		: Compatible list, must contain "fsl,imx35-esai" or
-			  "fsl,vf610-esai"
+  - compatible		: Compatible list, should contain one of the following
+			  compatibles:
+			  "fsl,imx35-esai",
+			  "fsl,vf610-esai",
+			  "fsl,imx6ull-esai",
 
   - reg			: Offset and length of the register set for the device.
 
-- 
2.21.0


^ permalink raw reply related

* [PATCH 1/2] ASoC: fsl_esai: Add compatible string for imx6ull
From: Shengjiu Wang @ 2019-08-09 10:27 UTC (permalink / raw)
  To: timur, nicoleotsuka, Xiubo.Lee, festevam, broonie, alsa-devel,
	robh+dt, mark.rutland
  Cc: devicetree, linuxppc-dev, linux-kernel

Add compatible string for imx6ull, from imx6ull platform,
the issue of channel swap after xrun is fixed in hardware.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 sound/soc/fsl/fsl_esai.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sound/soc/fsl/fsl_esai.c b/sound/soc/fsl/fsl_esai.c
index 10d2210c91ef..4b4a8e831e9e 100644
--- a/sound/soc/fsl/fsl_esai.c
+++ b/sound/soc/fsl/fsl_esai.c
@@ -920,6 +920,7 @@ static int fsl_esai_remove(struct platform_device *pdev)
 static const struct of_device_id fsl_esai_dt_ids[] = {
 	{ .compatible = "fsl,imx35-esai", },
 	{ .compatible = "fsl,vf610-esai", },
+	{ .compatible = "fsl,imx6ull-esai", },
 	{}
 };
 MODULE_DEVICE_TABLE(of, fsl_esai_dt_ids);
-- 
2.21.0


^ permalink raw reply related

* Re: [RFC V2 0/1] mm/debug: Add tests for architecture exported page table helpers
From: Mark Rutland @ 2019-08-09 11:44 UTC (permalink / raw)
  To: Matthew Wilcox
  Cc: linux-ia64, linux-sh, Tetsuo Handa, James Hogan, Heiko Carstens,
	Michal Hocko, linux-mm, Paul Mackerras, sparclinux,
	Thomas Gleixner, linux-s390, x86, Russell King - ARM Linux,
	Steven Price, Jason Gunthorpe, linux-arm-kernel, linux-snps-arc,
	Kees Cook, Anshuman Khandual, Masahiro Yamada, Mark Brown,
	Dan Williams, Vlastimil Babka, Sri Krishna chowdary,
	Ard Biesheuvel, Greg Kroah-Hartman, Dave Hansen, linux-mips,
	Ralf Baechle, linux-kernel, Peter Zijlstra, Mike Rapoport,
	Paul Burton, Vineet Gupta, Martin Schwidefsky, Andrew Morton,
	linuxppc-dev, David S. Miller
In-Reply-To: <20190809101632.GM5482@bombadil.infradead.org>

On Fri, Aug 09, 2019 at 03:16:33AM -0700, Matthew Wilcox wrote:
> On Fri, Aug 09, 2019 at 01:03:17PM +0530, Anshuman Khandual wrote:
> > Should alloc_gigantic_page() be made available as an interface for general
> > use in the kernel. The test module here uses very similar implementation from
> > HugeTLB to allocate a PUD aligned memory block. Similar for mm_alloc() which
> > needs to be exported through a header.
> 
> Why are you allocating memory at all instead of just using some
> known-to-exist PFNs like I suggested?

IIUC the issue is that there aren't necessarily known-to-exist PFNs that
are sufficiently aligned -- they may not even exist.

For example, with 64K pages, a PMD covers 512M. The kernel image is
(generally) smaller than 512M, and will be mapped at page granularity.
In that case, any PMD entry for a kernel symbol address will point to
the PTE level table, and that will only necessarily be page-aligned, as
any P?D level table is only necessarily page-aligned.

In the same configuration, you could have less than 512M of total
memory, and none of this memory is necessarily aligned to 512M. So
beyond the PTE level, I don't think you can guarantee a known-to-exist
valid PFN.

I also believe that synthetic PFNs could fail pfn_valid(), so that might
cause us pain too...

Thanks,
Mark.

^ permalink raw reply

* Re: [PATCH v3 38/41] powerpc: convert put_page() to put_user_page*()
From: Michael Ellerman @ 2019-08-09 12:20 UTC (permalink / raw)
  To: John Hubbard, Andrew Morton
  Cc: linux-fbdev, Jan Kara, kvm, Dave Hansen, Dave Chinner, dri-devel,
	linux-mm, sparclinux, Ira Weiny, ceph-devel, devel, rds-devel,
	linux-rdma, x86, amd-gfx, Christoph Hellwig, Christoph Hellwig,
	Jason Gunthorpe, xen-devel, devel, linux-media, intel-gfx,
	linux-block, Jérôme Glisse, linux-rpi-kernel,
	Dan Williams, linux-arm-kernel, linux-nfs, netdev, LKML,
	linux-xfs, linux-crypto, linux-fsdevel, linuxppc-dev
In-Reply-To: <248c9ab2-93cc-6d8b-606d-d85b83e791e5@nvidia.com>

John Hubbard <jhubbard@nvidia.com> writes:
> On 8/7/19 10:42 PM, Michael Ellerman wrote:
>> Hi John,
>> 
>> john.hubbard@gmail.com writes:
>>> diff --git a/arch/powerpc/mm/book3s64/iommu_api.c b/arch/powerpc/mm/book3s64/iommu_api.c
>>> index b056cae3388b..e126193ba295 100644
>>> --- a/arch/powerpc/mm/book3s64/iommu_api.c
>>> +++ b/arch/powerpc/mm/book3s64/iommu_api.c
>>> @@ -203,6 +202,7 @@ static void mm_iommu_unpin(struct mm_iommu_table_group_mem_t *mem)
>>>  {
>>>  	long i;
>>>  	struct page *page = NULL;
>>> +	bool dirty = false;
>> 
>> I don't think you need that initialisation do you?
>> 
>
> Nope, it can go. Fixed locally, thanks.

Thanks.

> Did you get a chance to look at enough of the other bits to feel comfortable 
> with the patch, overall?

Mostly :) It's not really my area, but all the conversions looked
correct to me as best as I could tell.

So I'm fine for it to go in as part of the series:

Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)

cheers

^ permalink raw reply

* [Bug 204375] kernel 5.2.4 w. KASAN enabled fails to boot on a PowerMac G4 3,6 at very early stage
From: bugzilla-daemon @ 2019-08-09 12:25 UTC (permalink / raw)
  To: linuxppc-dev
In-Reply-To: <bug-204375-206035@https.bugzilla.kernel.org/>

https://bugzilla.kernel.org/show_bug.cgi?id=204375

Michael Ellerman (michael@ellerman.id.au) changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |CLOSED
                 CC|                            |michael@ellerman.id.au

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^ permalink raw reply


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