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* [PATCH v10 0/3] add support for rng-seed
@ 2019-08-23  6:24 Hsin-Yi Wang
  2019-08-23  6:24 ` [PATCH v10 1/3] arm64: map FDT as RW for early_init_dt_scan() Hsin-Yi Wang
                   ` (2 more replies)
  0 siblings, 3 replies; 9+ messages in thread
From: Hsin-Yi Wang @ 2019-08-23  6:24 UTC (permalink / raw)
  To: linux-arm-kernel, Theodore Y . Ts'o
  Cc: Kate Stewart, Peter Zijlstra, Catalin Marinas, Mukesh Ojha,
	Grzegorz Halat, H . Peter Anvin, Guenter Roeck, Will Deacon,
	Marek Szyprowski, Rob Herring, Daniel Thompson, Anders Roxell,
	Yury Norov, Marc Zyngier, Russell King, Aaro Koskinen,
	Ingo Molnar, Viresh Kumar, Waiman Long, Paul E . McKenney, Wei Li,
	Alexey Dobriyan, Julien Thierry, Len Brown, Kees Cook,
	Arnd Bergmann, Rik van Riel, Stephen Boyd, Shaokun Zhang,
	Mike Rapoport, Borislav Petkov, Josh Poimboeuf, Thomas Gleixner,
	Greg Kroah-Hartman, Marcelo Tosatti, linux-kernel, Armijn Hemel,
	Jiri Kosina, Mathieu Desnoyers, Andrew Morton, Tim Chen,
	David S . Miller

Introducing a chosen node, rng-seed, which is an entropy that can be
passed to kernel called very early to increase initial device
randomness. This can be used for adding sufficient initial entropy
for stack canary. Especially architectures that lack per-stack canary.

Hsin-Yi Wang (3):
  arm64: map FDT as RW for early_init_dt_scan()
  fdt: add support for rng-seed
  arm64: kexec_file: add rng-seed support

 arch/arm64/include/asm/mmu.h           |  2 +-
 arch/arm64/kernel/kaslr.c              |  5 +----
 arch/arm64/kernel/machine_kexec_file.c | 18 +++++++++++++++++-
 arch/arm64/kernel/setup.c              |  9 ++++++++-
 arch/arm64/mm/mmu.c                    | 15 +--------------
 drivers/char/Kconfig                   |  9 +++++++++
 drivers/char/random.c                  | 14 ++++++++++++++
 drivers/of/fdt.c                       | 14 ++++++++++++--
 include/linux/random.h                 |  1 +
 9 files changed, 64 insertions(+), 23 deletions(-)

-- 
2.20.1


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^ permalink raw reply	[flat|nested] 9+ messages in thread

• * [PATCH v10 1/3] arm64: map FDT as RW for early_init_dt_scan()
    2019-08-23  6:24 [PATCH v10 0/3] add support for rng-seed Hsin-Yi Wang
  @ 2019-08-23  6:24 ` Hsin-Yi Wang
    2019-08-23  6:24 ` [PATCH v10 2/3] fdt: add support for rng-seed Hsin-Yi Wang
    2019-08-23  6:24 ` [PATCH v10 3/3] arm64: kexec_file: add rng-seed support Hsin-Yi Wang
    2 siblings, 0 replies; 9+ messages in thread
  From: Hsin-Yi Wang @ 2019-08-23  6:24 UTC (permalink / raw)
    To: linux-arm-kernel, Theodore Y . Ts'o
    Cc: Kate Stewart, Peter Zijlstra, Catalin Marinas, Mukesh Ojha,
  	Grzegorz Halat, H . Peter Anvin, Guenter Roeck, Will Deacon,
  	Marek Szyprowski, Rob Herring, Daniel Thompson, Anders Roxell,
  	Yury Norov, Marc Zyngier, Russell King, Aaro Koskinen,
  	Ingo Molnar, Viresh Kumar, Waiman Long, Paul E . McKenney, Wei Li,
  	Alexey Dobriyan, Julien Thierry, Len Brown, Kees Cook,
  	Arnd Bergmann, Rik van Riel, Stephen Boyd, Shaokun Zhang,
  	Mike Rapoport, Borislav Petkov, Josh Poimboeuf, Thomas Gleixner,
  	Greg Kroah-Hartman, Marcelo Tosatti, linux-kernel, Armijn Hemel,
  	Jiri Kosina, Mathieu Desnoyers, Andrew Morton, Tim Chen,
  	David S . Miller
  
  Currently in arm64, FDT is mapped to RO before it's passed to
  early_init_dt_scan(). However, there might be some codes
  (eg. commit "fdt: add support for rng-seed") that need to modify FDT
  during init. Map FDT to RO after early fixups are done.
  
  Signed-off-by: Hsin-Yi Wang <hsinyi@chromium•org>
  Reviewed-by: Stephen Boyd <swboyd@chromium•org>
  Reviewed-by: Mike Rapoport <rppt@linux•ibm.com>
  ---
  No change since v7
  ---
   arch/arm64/include/asm/mmu.h |  2 +-
   arch/arm64/kernel/kaslr.c    |  5 +----
   arch/arm64/kernel/setup.c    |  9 ++++++++-
   arch/arm64/mm/mmu.c          | 15 +--------------
   4 files changed, 11 insertions(+), 20 deletions(-)
  
  diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
  index fd6161336653..f217e3292919 100644
  --- a/arch/arm64/include/asm/mmu.h
  +++ b/arch/arm64/include/asm/mmu.h
  @@ -126,7 +126,7 @@ extern void init_mem_pgprot(void);
   extern void create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
   			       unsigned long virt, phys_addr_t size,
   			       pgprot_t prot, bool page_mappings_only);
  -extern void *fixmap_remap_fdt(phys_addr_t dt_phys);
  +extern void *fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot);
   extern void mark_linear_text_alias_ro(void);
   
   #define INIT_MM_CONTEXT(name)	\
  diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c
  index 5a59f7567f9c..416f537bf614 100644
  --- a/arch/arm64/kernel/kaslr.c
  +++ b/arch/arm64/kernel/kaslr.c
  @@ -62,9 +62,6 @@ static __init const u8 *kaslr_get_cmdline(void *fdt)
   	return default_cmdline;
   }
   
  -extern void *__init __fixmap_remap_fdt(phys_addr_t dt_phys, int *size,
  -				       pgprot_t prot);
  -
   /*
    * This routine will be executed with the kernel mapped at its default virtual
    * address, and if it returns successfully, the kernel will be remapped, and
  @@ -93,7 +90,7 @@ u64 __init kaslr_early_init(u64 dt_phys)
   	 * attempt at mapping the FDT in setup_machine()
   	 */
   	early_fixmap_init();
  -	fdt = __fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL);
  +	fdt = fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL);
   	if (!fdt)
   		return 0;
   
  diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
  index 57ff38600828..56f664561754 100644
  --- a/arch/arm64/kernel/setup.c
  +++ b/arch/arm64/kernel/setup.c
  @@ -170,9 +170,13 @@ static void __init smp_build_mpidr_hash(void)
   
   static void __init setup_machine_fdt(phys_addr_t dt_phys)
   {
  -	void *dt_virt = fixmap_remap_fdt(dt_phys);
  +	int size;
  +	void *dt_virt = fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL);
   	const char *name;
   
  +	if (dt_virt)
  +		memblock_reserve(dt_phys, size);
  +
   	if (!dt_virt || !early_init_dt_scan(dt_virt)) {
   		pr_crit("\n"
   			"Error: invalid device tree blob at physical address %pa (virtual address 0x%p)\n"
  @@ -184,6 +188,9 @@ static void __init setup_machine_fdt(phys_addr_t dt_phys)
   			cpu_relax();
   	}
   
  +	/* Early fixups are done, map the FDT as read-only now */
  +	fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL_RO);
  +
   	name = of_flat_dt_get_machine_name();
   	if (!name)
   		return;
  diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
  index e67bab4d613e..1586d7fbf26a 100644
  --- a/arch/arm64/mm/mmu.c
  +++ b/arch/arm64/mm/mmu.c
  @@ -877,7 +877,7 @@ void __set_fixmap(enum fixed_addresses idx,
   	}
   }
   
  -void *__init __fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot)
  +void *__init fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot)
   {
   	const u64 dt_virt_base = __fix_to_virt(FIX_FDT);
   	int offset;
  @@ -930,19 +930,6 @@ void *__init __fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot)
   	return dt_virt;
   }
   
  -void *__init fixmap_remap_fdt(phys_addr_t dt_phys)
  -{
  -	void *dt_virt;
  -	int size;
  -
  -	dt_virt = __fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL_RO);
  -	if (!dt_virt)
  -		return NULL;
  -
  -	memblock_reserve(dt_phys, size);
  -	return dt_virt;
  -}
  -
   int __init arch_ioremap_p4d_supported(void)
   {
   	return 0;
  -- 
  2.20.1
  
  
  _______________________________________________
  linux-arm-kernel mailing list
  linux-arm-kernel@lists•infradead.org
  http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
  
  ^ permalink raw reply related	[flat|nested] 9+ messages in thread

• * [PATCH v10 2/3] fdt: add support for rng-seed
    2019-08-23  6:24 [PATCH v10 0/3] add support for rng-seed Hsin-Yi Wang
    2019-08-23  6:24 ` [PATCH v10 1/3] arm64: map FDT as RW for early_init_dt_scan() Hsin-Yi Wang
  @ 2019-08-23  6:24 ` Hsin-Yi Wang
    2019-08-23 15:41   ` Will Deacon
    2019-08-23  6:24 ` [PATCH v10 3/3] arm64: kexec_file: add rng-seed support Hsin-Yi Wang
    2 siblings, 1 reply; 9+ messages in thread
  From: Hsin-Yi Wang @ 2019-08-23  6:24 UTC (permalink / raw)
    To: linux-arm-kernel, Theodore Y . Ts'o
    Cc: Kate Stewart, Peter Zijlstra, Catalin Marinas, Mukesh Ojha,
  	Grzegorz Halat, H . Peter Anvin, Guenter Roeck, Will Deacon,
  	Marek Szyprowski, Rob Herring, Daniel Thompson, Anders Roxell,
  	Yury Norov, Marc Zyngier, Russell King, Aaro Koskinen,
  	Ingo Molnar, Viresh Kumar, Waiman Long, Paul E . McKenney, Wei Li,
  	Alexey Dobriyan, Julien Thierry, Len Brown, Kees Cook,
  	Arnd Bergmann, Rik van Riel, Stephen Boyd, Shaokun Zhang,
  	Mike Rapoport, Borislav Petkov, Josh Poimboeuf, Thomas Gleixner,
  	Greg Kroah-Hartman, Marcelo Tosatti, linux-kernel, Armijn Hemel,
  	Jiri Kosina, Mathieu Desnoyers, Andrew Morton, Tim Chen,
  	David S . Miller
  
  Introducing a chosen node, rng-seed, which is an entropy that can be
  passed to kernel called very early to increase initial device
  randomness. Bootloader should provide this entropy and the value is
  read from /chosen/rng-seed in DT.
  
  Obtain of_fdt_crc32 for CRC check after early_init_dt_scan_nodes(),
  since early_init_dt_scan_chosen() would modify fdt to erase rng-seed.
  
  Add a new interface add_bootloader_randomness() for rng-seed use case.
  Depends on whether the seed is trustworthy, rng seed would be passed to
  add_hwgenerator_randomness(). Otherwise it would be passed to
  add_device_randomness(). Decision is controlled by kernel config
  RANDOM_TRUST_BOOTLOADER.
  
  Signed-off-by: Hsin-Yi Wang <hsinyi@chromium•org>
  Reviewed-by: Stephen Boyd <swboyd@chromium•org>
  Reviewed-by: Rob Herring <robh@kernel•org>
  ---
  Change from v9:
  * reword kconfig
  * use IS_ENABLED for config
  ---
   drivers/char/Kconfig   |  9 +++++++++
   drivers/char/random.c  | 14 ++++++++++++++
   drivers/of/fdt.c       | 14 ++++++++++++--
   include/linux/random.h |  1 +
   4 files changed, 36 insertions(+), 2 deletions(-)
  
  diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
  index 96156c729a31..df0fc997dc3e 100644
  --- a/drivers/char/Kconfig
  +++ b/drivers/char/Kconfig
  @@ -551,3 +551,12 @@ config RANDOM_TRUST_CPU
   	has not installed a hidden back door to compromise the CPU's
   	random number generation facilities. This can also be configured
   	at boot with "random.trust_cpu=on/off".
  +
  +config RANDOM_TRUST_BOOTLOADER
  +	bool "Trust the bootloader to initialize Linux's CRNG"
  +	help
  +	Some bootloaders can provide entropy to increase the kernel's initial
  +	device randomness. Say Y here to assume the entropy provided by the
  +	booloader is trustworthy so it will be added to the kernel's entropy
  +	pool. Otherwise, say N here so it will be regarded as device input that
  +	only mixes the entropy pool.
  \ No newline at end of file
  diff --git a/drivers/char/random.c b/drivers/char/random.c
  index 5d5ea4ce1442..566922df4b7b 100644
  --- a/drivers/char/random.c
  +++ b/drivers/char/random.c
  @@ -2445,3 +2445,17 @@ void add_hwgenerator_randomness(const char *buffer, size_t count,
   	credit_entropy_bits(poolp, entropy);
   }
   EXPORT_SYMBOL_GPL(add_hwgenerator_randomness);
  +
  +/* Handle random seed passed by bootloader.
  + * If the seed is trustworthy, it would be regarded as hardware RNGs. Otherwise
  + * it would be regarded as device data.
  + * The decision is controlled by CONFIG_RANDOM_TRUST_BOOTLOADER.
  + */
  +void add_bootloader_randomness(const void *buf, unsigned int size)
  +{
  +	if (IS_ENABLED(CONFIG_RANDOM_TRUST_BOOTLOADER))
  +		add_hwgenerator_randomness(buf, size, size * 8);
  +	else
  +		add_device_randomness(buf, size);
  +}
  +EXPORT_SYMBOL_GPL(add_bootloader_randomness);
  \ No newline at end of file
  diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
  index 9cdf14b9aaab..7d97ab6d0e31 100644
  --- a/drivers/of/fdt.c
  +++ b/drivers/of/fdt.c
  @@ -24,6 +24,7 @@
   #include <linux/debugfs.h>
   #include <linux/serial_core.h>
   #include <linux/sysfs.h>
  +#include <linux/random.h>
   
   #include <asm/setup.h>  /* for COMMAND_LINE_SIZE */
   #include <asm/page.h>
  @@ -1044,6 +1045,7 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
   {
   	int l;
   	const char *p;
  +	const void *rng_seed;
   
   	pr_debug("search \"chosen\", depth: %d, uname: %s\n", depth, uname);
   
  @@ -1078,6 +1080,14 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname,
   
   	pr_debug("Command line is: %s\n", (char*)data);
   
  +	rng_seed = of_get_flat_dt_prop(node, "rng-seed", &l);
  +	if (rng_seed && l > 0) {
  +		add_bootloader_randomness(rng_seed, l);
  +
  +		/* try to clear seed so it won't be found. */
  +		fdt_nop_property(initial_boot_params, node, "rng-seed");
  +	}
  +
   	/* break now */
   	return 1;
   }
  @@ -1166,8 +1176,6 @@ bool __init early_init_dt_verify(void *params)
   
   	/* Setup flat device-tree pointer */
   	initial_boot_params = params;
  -	of_fdt_crc32 = crc32_be(~0, initial_boot_params,
  -				fdt_totalsize(initial_boot_params));
   	return true;
   }
   
  @@ -1197,6 +1205,8 @@ bool __init early_init_dt_scan(void *params)
   		return false;
   
   	early_init_dt_scan_nodes();
  +	of_fdt_crc32 = crc32_be(~0, initial_boot_params,
  +				fdt_totalsize(initial_boot_params));
   	return true;
   }
   
  diff --git a/include/linux/random.h b/include/linux/random.h
  index 1f7dced2bba6..f189c927fdea 100644
  --- a/include/linux/random.h
  +++ b/include/linux/random.h
  @@ -19,6 +19,7 @@ struct random_ready_callback {
   };
   
   extern void add_device_randomness(const void *, unsigned int);
  +extern void add_bootloader_randomness(const void *, unsigned int);
   
   #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
   static inline void add_latent_entropy(void)
  -- 
  2.20.1
  
  
  _______________________________________________
  linux-arm-kernel mailing list
  linux-arm-kernel@lists•infradead.org
  http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
  
  ^ permalink raw reply related	[flat|nested] 9+ messages in thread

• • * Re: [PATCH v10 2/3] fdt: add support for rng-seed
      2019-08-23  6:24 ` [PATCH v10 2/3] fdt: add support for rng-seed Hsin-Yi Wang
    @ 2019-08-23 15:41   ` Will Deacon
      2019-08-23 16:06     ` Theodore Y. Ts'o
      2019-08-27  9:17     ` Geert Uytterhoeven
      0 siblings, 2 replies; 9+ messages in thread
    From: Will Deacon @ 2019-08-23 15:41 UTC (permalink / raw)
      To: Hsin-Yi Wang, tytso
      Cc: Kate Stewart, Peter Zijlstra, Catalin Marinas, Mukesh Ojha,
    	Grzegorz Halat, H . Peter Anvin, Guenter Roeck, Marek Szyprowski,
    	Rob Herring, Daniel Thompson, Anders Roxell, Yury Norov,
    	Marc Zyngier, Russell King, Aaro Koskinen, Ingo Molnar,
    	Viresh Kumar, Waiman Long, Paul E . McKenney, Wei Li,
    	Alexey Dobriyan, Julien Thierry, Len Brown, Kees Cook,
    	Arnd Bergmann, Rik van Riel, Stephen Boyd, Shaokun Zhang,
    	Mike Rapoport, Borislav Petkov, Josh Poimboeuf, Thomas Gleixner,
    	linux-arm-kernel, Greg Kroah-Hartman, Marcelo Tosatti,
    	linux-kernel, Armijn Hemel, Jiri Kosina, Mathieu Desnoyers,
    	Andrew Morton, Tim Chen, David S . Miller
    
    On Fri, Aug 23, 2019 at 02:24:51PM +0800, Hsin-Yi Wang wrote:
    > Introducing a chosen node, rng-seed, which is an entropy that can be
    > passed to kernel called very early to increase initial device
    > randomness. Bootloader should provide this entropy and the value is
    > read from /chosen/rng-seed in DT.
    > 
    > Obtain of_fdt_crc32 for CRC check after early_init_dt_scan_nodes(),
    > since early_init_dt_scan_chosen() would modify fdt to erase rng-seed.
    > 
    > Add a new interface add_bootloader_randomness() for rng-seed use case.
    > Depends on whether the seed is trustworthy, rng seed would be passed to
    > add_hwgenerator_randomness(). Otherwise it would be passed to
    > add_device_randomness(). Decision is controlled by kernel config
    > RANDOM_TRUST_BOOTLOADER.
    > 
    > Signed-off-by: Hsin-Yi Wang <hsinyi@chromium•org>
    > Reviewed-by: Stephen Boyd <swboyd@chromium•org>
    > Reviewed-by: Rob Herring <robh@kernel•org>
    > ---
    > Change from v9:
    > * reword kconfig
    > * use IS_ENABLED for config
    
    Given that these aren't functional changes, I've kept Ted's ack from v9
    and I'll queue these via arm64 assuming they pass testing.
    
    Ted -- please shout if you're not happy about that, and I'll drop the
    series.
    
    Thanks,
    
    Will
    
    _______________________________________________
    linux-arm-kernel mailing list
    linux-arm-kernel@lists•infradead.org
    http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
    
    ^ permalink raw reply	[flat|nested] 9+ messages in thread

  • • * Re: [PATCH v10 2/3] fdt: add support for rng-seed
        2019-08-23 15:41   ` Will Deacon
      @ 2019-08-23 16:06     ` Theodore Y. Ts'o
        2019-08-23 16:31       ` Will Deacon
        2019-08-27  9:17     ` Geert Uytterhoeven
        1 sibling, 1 reply; 9+ messages in thread
      From: Theodore Y. Ts'o @ 2019-08-23 16:06 UTC (permalink / raw)
        To: Will Deacon
        Cc: Kate Stewart, Peter Zijlstra, Catalin Marinas, Mukesh Ojha,
      	Josh Poimboeuf, Grzegorz Halat, H . Peter Anvin, Guenter Roeck,
      	Marek Szyprowski, Rob Herring, Daniel Thompson, Anders Roxell,
      	Yury Norov, Marc Zyngier, Russell King, Aaro Koskinen,
      	Ingo Molnar, Viresh Kumar, Waiman Long, Paul E . McKenney, Wei Li,
      	Alexey Dobriyan, Julien Thierry, Len Brown, Kees Cook,
      	Arnd Bergmann, Rik van Riel, Stephen Boyd, Shaokun Zhang,
      	Mike Rapoport, Borislav Petkov, Hsin-Yi Wang, Thomas Gleixner,
      	linux-arm-kernel, Greg Kroah-Hartman, Marcelo Tosatti,
      	linux-kernel, Armijn Hemel, Jiri Kosina, Mathieu Desnoyers,
      	Andrew Morton, Tim Chen, David S . Miller
      
      On Fri, Aug 23, 2019 at 04:41:59PM +0100, Will Deacon wrote:
      > 
      > Given that these aren't functional changes, I've kept Ted's ack from v9
      > and I'll queue these via arm64 assuming they pass testing.
      > 
      > Ted -- please shout if you're not happy about that, and I'll drop the
      > series.
      
      That's fine, thanks.  I'm thinking about making some changes to
      add_hwgenerator_randomness(), but it's not going to be in the next
      merge window, and it's more important that we get the interfaces (the
      Kconfig options and add_bootloader_randomness() function prototype)
      right for ARM.
      
      Now to shanghai some volunteers to get this functionality working for
      x86 (at least for the UEFI and NERF bootloaders).  :-)
      
      Thanks!!
      
      						- Ted
      
      _______________________________________________
      linux-arm-kernel mailing list
      linux-arm-kernel@lists•infradead.org
      http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
      
      ^ permalink raw reply	[flat|nested] 9+ messages in thread

    • • * Re: [PATCH v10 2/3] fdt: add support for rng-seed
          2019-08-23 16:06     ` Theodore Y. Ts'o
        @ 2019-08-23 16:31       ` Will Deacon
          0 siblings, 0 replies; 9+ messages in thread
        From: Will Deacon @ 2019-08-23 16:31 UTC (permalink / raw)
          To: Theodore Y. Ts'o, Hsin-Yi Wang, linux-arm-kernel,
        	Russell King, Catalin Marinas, Thomas Gleixner, Ingo Molnar,
        	Borislav Petkov, H . Peter Anvin, Paul E . McKenney, Kate Stewart,
        	David S . Miller, Viresh Kumar, Marek Szyprowski, Arnd Bergmann,
        	Marc Zyngier, Julien Thierry, Greg Kroah-Hartman, Wei Li,
        	Anders Roxell, Rob Herring, Aaro Koskinen, Daniel Thompson,
        	Tim Chen, Rik van Riel, Waiman Long, Marcelo Tosatti,
        	Peter Zijlstra, Armijn Hemel, Grzegorz Halat, Len Brown,
        	Shaokun Zhang, Mike Rapoport, Kees Cook, Stephen Boyd,
        	Guenter Roeck, Andrew Morton, Mathieu Desnoyers, Alexey Dobriyan,
        	Yury Norov, Josh Poimboeuf, Jiri Kosina, Mukesh Ojha,
        	linux-kernel
        
        On Fri, Aug 23, 2019 at 12:06:12PM -0400, Theodore Y. Ts'o wrote:
        > On Fri, Aug 23, 2019 at 04:41:59PM +0100, Will Deacon wrote:
        > > 
        > > Given that these aren't functional changes, I've kept Ted's ack from v9
        > > and I'll queue these via arm64 assuming they pass testing.
        > > 
        > > Ted -- please shout if you're not happy about that, and I'll drop the
        > > series.
        > 
        > That's fine, thanks.  I'm thinking about making some changes to
        > add_hwgenerator_randomness(), but it's not going to be in the next
        > merge window, and it's more important that we get the interfaces (the
        > Kconfig options and add_bootloader_randomness() function prototype)
        > right for ARM.
        
        Well, on the off-chance that you do need it, I've stuck the series on its
        own branch anyway so you can pull in elsewhere if necessary:
        
        https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/log/?h=for-next/rng
        
        > Now to shanghai some volunteers to get this functionality working for
        > x86 (at least for the UEFI and NERF bootloaders).  :-)
        
        Hehe, good luck!
        
        Will
        
        _______________________________________________
        linux-arm-kernel mailing list
        linux-arm-kernel@lists•infradead.org
        http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
        
        ^ permalink raw reply	[flat|nested] 9+ messages in thread

    • * Re: [PATCH v10 2/3] fdt: add support for rng-seed
        2019-08-23 15:41   ` Will Deacon
        2019-08-23 16:06     ` Theodore Y. Ts'o
      @ 2019-08-27  9:17     ` Geert Uytterhoeven
        2019-08-27  9:42       ` Hsin-Yi Wang
        1 sibling, 1 reply; 9+ messages in thread
      From: Geert Uytterhoeven @ 2019-08-27  9:17 UTC (permalink / raw)
        To: Will Deacon, Hsin-Yi Wang
        Cc: Kate Stewart, Peter Zijlstra, Catalin Marinas, Mukesh Ojha,
      	Grzegorz Halat, H . Peter Anvin, Guenter Roeck, Marek Szyprowski,
      	Rob Herring, Daniel Thompson, Anders Roxell, Yury Norov,
      	Marc Zyngier, Russell King, Aaro Koskinen, Ingo Molnar,
      	Viresh Kumar, Waiman Long, Paul E . McKenney, Wei Li,
      	Alexey Dobriyan, Julien Thierry, Len Brown, Kees Cook,
      	Arnd Bergmann, Rik van Riel, Stephen Boyd, Shaokun Zhang,
      	Mike Rapoport, Borislav Petkov, Josh Poimboeuf, Thomas Gleixner,
      	Linux ARM, Theodore Tso, Greg Kroah-Hartman, Marcelo Tosatti,
      	Linux Kernel Mailing List, Linux-Renesas, Armijn Hemel,
      	Jiri Kosina, Mathieu Desnoyers, Andrew Morton, Tim Chen,
      	David S . Miller
      
      Hi Will, Hsin-Yi,
      
      On Fri, Aug 23, 2019 at 5:42 PM Will Deacon <will@kernel•org> wrote:
      > On Fri, Aug 23, 2019 at 02:24:51PM +0800, Hsin-Yi Wang wrote:
      > > Introducing a chosen node, rng-seed, which is an entropy that can be
      > > passed to kernel called very early to increase initial device
      > > randomness. Bootloader should provide this entropy and the value is
      > > read from /chosen/rng-seed in DT.
      > >
      > > Obtain of_fdt_crc32 for CRC check after early_init_dt_scan_nodes(),
      > > since early_init_dt_scan_chosen() would modify fdt to erase rng-seed.
      > >
      > > Add a new interface add_bootloader_randomness() for rng-seed use case.
      > > Depends on whether the seed is trustworthy, rng seed would be passed to
      > > add_hwgenerator_randomness(). Otherwise it would be passed to
      > > add_device_randomness(). Decision is controlled by kernel config
      > > RANDOM_TRUST_BOOTLOADER.
      > >
      > > Signed-off-by: Hsin-Yi Wang <hsinyi@chromium•org>
      > > Reviewed-by: Stephen Boyd <swboyd@chromium•org>
      > > Reviewed-by: Rob Herring <robh@kernel•org>
      > > ---
      > > Change from v9:
      > > * reword kconfig
      > > * use IS_ENABLED for config
      >
      > Given that these aren't functional changes, I've kept Ted's ack from v9
      > and I'll queue these via arm64 assuming they pass testing.
      
      This is now commit 428826f5358c922d ("fdt: add support for rng-seed")
      in arm64/for-next/core, and causes the following regression on arm32
      (e.g. r8a7791/koelsch, and sh73a0/kzm9g):
      
          OF: fdt: not creating '/sys/firmware/fdt': CRC check failed
      
      Seems to work fine on arm64 (r8a7795/h3-salvator-xs), though.
      
      Gr{oetje,eeting}s,
      
                              Geert
      
      -- 
      Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k•org
      
      In personal conversations with technical people, I call myself a hacker. But
      when I'm talking to journalists I just say "programmer" or something like that.
                                      -- Linus Torvalds
      
      _______________________________________________
      linux-arm-kernel mailing list
      linux-arm-kernel@lists•infradead.org
      http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
      
      ^ permalink raw reply	[flat|nested] 9+ messages in thread

    • • * Re: [PATCH v10 2/3] fdt: add support for rng-seed
          2019-08-27  9:17     ` Geert Uytterhoeven
        @ 2019-08-27  9:42       ` Hsin-Yi Wang
          0 siblings, 0 replies; 9+ messages in thread
        From: Hsin-Yi Wang @ 2019-08-27  9:42 UTC (permalink / raw)
          To: Geert Uytterhoeven, Will Deacon
          Cc: Kate Stewart, Peter Zijlstra, Catalin Marinas, Mukesh Ojha,
        	Grzegorz Halat, H . Peter Anvin, Guenter Roeck, Marek Szyprowski,
        	Rob Herring, Daniel Thompson, Anders Roxell, Yury Norov,
        	Marc Zyngier, Russell King, Aaro Koskinen, Ingo Molnar,
        	Viresh Kumar, Waiman Long, Paul E . McKenney, Wei Li,
        	Alexey Dobriyan, Julien Thierry, Len Brown, Kees Cook,
        	Arnd Bergmann, Rik van Riel, Stephen Boyd, Shaokun Zhang,
        	Mike Rapoport, Borislav Petkov, Josh Poimboeuf, Thomas Gleixner,
        	Linux ARM, Theodore Tso, Greg Kroah-Hartman, Marcelo Tosatti,
        	Linux Kernel Mailing List, Linux-Renesas, Armijn Hemel,
        	Jiri Kosina, Mathieu Desnoyers, Andrew Morton, Tim Chen,
        	David S . Miller
        
        I probably shouldn't move of_fdt_crc32 from early_init_dt_verify() to
        early_init_dt_scan() after early_init_dt_scan_nodes().
        Since arm doesn't call early_init_dt_scan(). It calls
        early_init_dt_verify() and early_init_dt_scan_nodes(). While arm64
        calls early_init_dt_scan().
        Sorry for not checking on arm.
        
        Since it's early_init_dt_scan_nodes() that would modify DT, I'll still
        leave of_fdt_crc32 be in early_init_dt_verify() and update it in
        early_init_dt_scan_chosen() if rng-seed is wiped from dt.
        
        
        On Tue, Aug 27, 2019 at 5:18 PM Geert Uytterhoeven <geert@linux-m68k•org> wrote:
        >
        > Hi Will, Hsin-Yi,
        >
        > On Fri, Aug 23, 2019 at 5:42 PM Will Deacon <will@kernel•org> wrote:
        > > On Fri, Aug 23, 2019 at 02:24:51PM +0800, Hsin-Yi Wang wrote:
        > > > Introducing a chosen node, rng-seed, which is an entropy that can be
        > > > passed to kernel called very early to increase initial device
        > > > randomness. Bootloader should provide this entropy and the value is
        > > > read from /chosen/rng-seed in DT.
        > > >
        > > > Obtain of_fdt_crc32 for CRC check after early_init_dt_scan_nodes(),
        > > > since early_init_dt_scan_chosen() would modify fdt to erase rng-seed.
        > > >
        > > > Add a new interface add_bootloader_randomness() for rng-seed use case.
        > > > Depends on whether the seed is trustworthy, rng seed would be passed to
        > > > add_hwgenerator_randomness(). Otherwise it would be passed to
        > > > add_device_randomness(). Decision is controlled by kernel config
        > > > RANDOM_TRUST_BOOTLOADER.
        > > >
        > > > Signed-off-by: Hsin-Yi Wang <hsinyi@chromium•org>
        > > > Reviewed-by: Stephen Boyd <swboyd@chromium•org>
        > > > Reviewed-by: Rob Herring <robh@kernel•org>
        > > > ---
        > > > Change from v9:
        > > > * reword kconfig
        > > > * use IS_ENABLED for config
        > >
        > > Given that these aren't functional changes, I've kept Ted's ack from v9
        > > and I'll queue these via arm64 assuming they pass testing.
        >
        > This is now commit 428826f5358c922d ("fdt: add support for rng-seed")
        > in arm64/for-next/core, and causes the following regression on arm32
        > (e.g. r8a7791/koelsch, and sh73a0/kzm9g):
        >
        >     OF: fdt: not creating '/sys/firmware/fdt': CRC check failed
        >
        > Seems to work fine on arm64 (r8a7795/h3-salvator-xs), though.
        >
        > Gr{oetje,eeting}s,
        >
        >                         Geert
        >
        > --
        > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k•org
        >
        > In personal conversations with technical people, I call myself a hacker. But
        > when I'm talking to journalists I just say "programmer" or something like that.
        >                                 -- Linus Torvalds
        
        _______________________________________________
        linux-arm-kernel mailing list
        linux-arm-kernel@lists•infradead.org
        http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
        
        ^ permalink raw reply	[flat|nested] 9+ messages in thread

• * [PATCH v10 3/3] arm64: kexec_file: add rng-seed support
    2019-08-23  6:24 [PATCH v10 0/3] add support for rng-seed Hsin-Yi Wang
    2019-08-23  6:24 ` [PATCH v10 1/3] arm64: map FDT as RW for early_init_dt_scan() Hsin-Yi Wang
    2019-08-23  6:24 ` [PATCH v10 2/3] fdt: add support for rng-seed Hsin-Yi Wang
  @ 2019-08-23  6:24 ` Hsin-Yi Wang
    2 siblings, 0 replies; 9+ messages in thread
  From: Hsin-Yi Wang @ 2019-08-23  6:24 UTC (permalink / raw)
    To: linux-arm-kernel, Theodore Y . Ts'o
    Cc: Kate Stewart, Peter Zijlstra, Catalin Marinas, Mukesh Ojha,
  	Grzegorz Halat, H . Peter Anvin, Guenter Roeck, Will Deacon,
  	Marek Szyprowski, Rob Herring, Daniel Thompson, Anders Roxell,
  	Yury Norov, Marc Zyngier, Russell King, Aaro Koskinen,
  	Ingo Molnar, Viresh Kumar, Waiman Long, Paul E . McKenney, Wei Li,
  	Alexey Dobriyan, Julien Thierry, Len Brown, Kees Cook,
  	Arnd Bergmann, Rik van Riel, Stephen Boyd, Shaokun Zhang,
  	Mike Rapoport, Borislav Petkov, Josh Poimboeuf, Thomas Gleixner,
  	Greg Kroah-Hartman, Marcelo Tosatti, linux-kernel, Armijn Hemel,
  	Jiri Kosina, Mathieu Desnoyers, Andrew Morton, Tim Chen,
  	David S . Miller
  
  Adding "rng-seed" to dtb. It's fine to add this property if original
  fdt doesn't contain it. Since original seed will be wiped after
  read, so use a default size 128 bytes here.
  
  Signed-off-by: Hsin-Yi Wang <hsinyi@chromium•org>
  Reviewed-by: Stephen Boyd <swboyd@chromium•org>
  ---
  No change since v7
  ---
   arch/arm64/kernel/machine_kexec_file.c | 18 +++++++++++++++++-
   1 file changed, 17 insertions(+), 1 deletion(-)
  
  diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
  index ba78ee7ca990..7b08bf9499b6 100644
  --- a/arch/arm64/kernel/machine_kexec_file.c
  +++ b/arch/arm64/kernel/machine_kexec_file.c
  @@ -27,6 +27,8 @@
   #define FDT_PROP_INITRD_END	"linux,initrd-end"
   #define FDT_PROP_BOOTARGS	"bootargs"
   #define FDT_PROP_KASLR_SEED	"kaslr-seed"
  +#define FDT_PROP_RNG_SEED	"rng-seed"
  +#define RNG_SEED_SIZE		128
   
   const struct kexec_file_ops * const kexec_file_loaders[] = {
   	&kexec_image_ops,
  @@ -102,6 +104,19 @@ static int setup_dtb(struct kimage *image,
   				FDT_PROP_KASLR_SEED);
   	}
   
  +	/* add rng-seed */
  +	if (rng_is_initialized()) {
  +		u8 rng_seed[RNG_SEED_SIZE];
  +		get_random_bytes(rng_seed, RNG_SEED_SIZE);
  +		ret = fdt_setprop(dtb, off, FDT_PROP_RNG_SEED, rng_seed,
  +				RNG_SEED_SIZE);
  +		if (ret)
  +			goto out;
  +	} else {
  +		pr_notice("RNG is not initialised: omitting \"%s\" property\n",
  +				FDT_PROP_RNG_SEED);
  +	}
  +
   out:
   	if (ret)
   		return (ret == -FDT_ERR_NOSPACE) ? -ENOMEM : -EINVAL;
  @@ -110,7 +125,8 @@ static int setup_dtb(struct kimage *image,
   }
   
   /*
  - * More space needed so that we can add initrd, bootargs and kaslr-seed.
  + * More space needed so that we can add initrd, bootargs, kaslr-seed, and
  + * rng-seed.
    */
   #define DTB_EXTRA_SPACE 0x1000
   
  -- 
  2.20.1
  
  
  _______________________________________________
  linux-arm-kernel mailing list
  linux-arm-kernel@lists•infradead.org
  http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
  
  ^ permalink raw reply related	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2019-08-27  9:43 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-08-23  6:24 [PATCH v10 0/3] add support for rng-seed Hsin-Yi Wang
2019-08-23  6:24 ` [PATCH v10 1/3] arm64: map FDT as RW for early_init_dt_scan() Hsin-Yi Wang
2019-08-23  6:24 ` [PATCH v10 2/3] fdt: add support for rng-seed Hsin-Yi Wang
2019-08-23 15:41   ` Will Deacon
2019-08-23 16:06     ` Theodore Y. Ts'o
2019-08-23 16:31       ` Will Deacon
2019-08-27  9:17     ` Geert Uytterhoeven
2019-08-27  9:42       ` Hsin-Yi Wang
2019-08-23  6:24 ` [PATCH v10 3/3] arm64: kexec_file: add rng-seed support Hsin-Yi Wang

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