[v4.9] Fixes to linux-4.9.y stable tree swab.h and random initialization

[v4.9] Fixes to linux-4.9.y stable tree swab.h and random initialization

[Hans-Christian Noren Egtvedt]

I discovered one regression when I merged 4.9.320 for one of our
platforms, the include of swab.h from user space (libudev) triggered the
error described in https://lkml.org/lkml/2020/2/12/93

Cherry picking that commit solved the problem as expected.
[v4.9 PATCH 1/6] include/uapi/linux/swab.h: fix userspace breakage,

Then the next part of this series:
[v4.9 PATCH 2/6] init/main: Fix double "the" in comment
[v4.9 PATCH 3/6] init/main: properly align the multi-line comment
[v4.9 PATCH 4/6] init: move stack canary initialization after
[v4.9 PATCH 5/6] init/main.c: extract early boot entropy from the
[v4.9 PATCH 6/6] random: move rand_initialize() earlier

Is to get the code flow similar in linux-4.9.y compared to HEAD
implementation. I suspect there is a not completely ok merge conflict
that was resolved during backport to linux-4.9.y branch with regards to
the 'random: move rand_initialize() earlier' commit.

Now the code flow is in the same order as latest HEAD.

-- 
Best regards, Hans-Christian Noren Egtvedt.

[v4.9 PATCH 1/6] include/uapi/linux/swab.h: fix userspace breakage, use __BITS_PER_LONG for swap

[Hans-Christian Noren Egtvedt]

From: Christian Borntraeger <borntraeger@de.ibm.com>

QEMU has a funny new build error message when I use the upstream kernel
headers:

      CC      block/file-posix.o
    In file included from /home/cborntra/REPOS/qemu/include/qemu/timer.h:4,
                     from /home/cborntra/REPOS/qemu/include/qemu/timed-average.h:29,
                     from /home/cborntra/REPOS/qemu/include/block/accounting.h:28,
                     from /home/cborntra/REPOS/qemu/include/block/block_int.h:27,
                     from /home/cborntra/REPOS/qemu/block/file-posix.c:30:
    /usr/include/linux/swab.h: In function `__swab':
    /home/cborntra/REPOS/qemu/include/qemu/bitops.h:20:34: error: "sizeof" is not defined, evaluates to 0 [-Werror=undef]
       20 | #define BITS_PER_LONG           (sizeof (unsigned long) * BITS_PER_BYTE)
          |                                  ^~~~~~
    /home/cborntra/REPOS/qemu/include/qemu/bitops.h:20:41: error: missing binary operator before token "("
       20 | #define BITS_PER_LONG           (sizeof (unsigned long) * BITS_PER_BYTE)
          |                                         ^
    cc1: all warnings being treated as errors
    make: *** [/home/cborntra/REPOS/qemu/rules.mak:69: block/file-posix.o] Error 1
    rm tests/qemu-iotests/socket_scm_helper.o

This was triggered by commit d5767057c9a ("uapi: rename ext2_swab() to
swab() and share globally in swab.h").  That patch is doing

  #include <asm/bitsperlong.h>

but it uses BITS_PER_LONG.

The kernel file asm/bitsperlong.h provide only __BITS_PER_LONG.

Let us use the __ variant in swap.h

Link: http://lkml.kernel.org/r/20200213142147.17604-1-borntraeger@de.ibm.com
Fixes: d5767057c9a ("uapi: rename ext2_swab() to swab() and share globally in swab.h")
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Allison Randal <allison@lohutok.net>
Cc: Joe Perches <joe@perches.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: Torsten Hilbrich <torsten.hilbrich@secunet.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 467d12f5c7842896d2de3ced74e4147ee29e97c8)
---
 include/uapi/linux/swab.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/uapi/linux/swab.h b/include/uapi/linux/swab.h
index 1f42d110987..51502eabdb0 100644
--- a/include/uapi/linux/swab.h
+++ b/include/uapi/linux/swab.h
@@ -134,9 +134,9 @@ static inline __attribute_const__ __u32 __fswahb32(__u32 val)
 
 static __always_inline unsigned long __swab(const unsigned long y)
 {
-#if BITS_PER_LONG == 64
+#if __BITS_PER_LONG == 64
 	return __swab64(y);
-#else /* BITS_PER_LONG == 32 */
+#else /* __BITS_PER_LONG == 32 */
 	return __swab32(y);
 #endif
 }
-- 
2.34.1

Re: [v4.9 PATCH 1/6] include/uapi/linux/swab.h: fix userspace breakage, use __BITS_PER_LONG for swap

[Greg KH]

On Sun, Jul 31, 2022 at 08:26:31PM +0200, Hans-Christian Noren Egtvedt wrote:
> From: Christian Borntraeger <borntraeger@de.ibm.com>
> 
> QEMU has a funny new build error message when I use the upstream kernel
> headers:
> 
>       CC      block/file-posix.o
>     In file included from /home/cborntra/REPOS/qemu/include/qemu/timer.h:4,
>                      from /home/cborntra/REPOS/qemu/include/qemu/timed-average.h:29,
>                      from /home/cborntra/REPOS/qemu/include/block/accounting.h:28,
>                      from /home/cborntra/REPOS/qemu/include/block/block_int.h:27,
>                      from /home/cborntra/REPOS/qemu/block/file-posix.c:30:
>     /usr/include/linux/swab.h: In function `__swab':
>     /home/cborntra/REPOS/qemu/include/qemu/bitops.h:20:34: error: "sizeof" is not defined, evaluates to 0 [-Werror=undef]
>        20 | #define BITS_PER_LONG           (sizeof (unsigned long) * BITS_PER_BYTE)
>           |                                  ^~~~~~
>     /home/cborntra/REPOS/qemu/include/qemu/bitops.h:20:41: error: missing binary operator before token "("
>        20 | #define BITS_PER_LONG           (sizeof (unsigned long) * BITS_PER_BYTE)
>           |                                         ^
>     cc1: all warnings being treated as errors
>     make: *** [/home/cborntra/REPOS/qemu/rules.mak:69: block/file-posix.o] Error 1
>     rm tests/qemu-iotests/socket_scm_helper.o
> 
> This was triggered by commit d5767057c9a ("uapi: rename ext2_swab() to
> swab() and share globally in swab.h").  That patch is doing
> 
>   #include <asm/bitsperlong.h>
> 
> but it uses BITS_PER_LONG.
> 
> The kernel file asm/bitsperlong.h provide only __BITS_PER_LONG.
> 
> Let us use the __ variant in swap.h
> 
> Link: http://lkml.kernel.org/r/20200213142147.17604-1-borntraeger@de.ibm.com
> Fixes: d5767057c9a ("uapi: rename ext2_swab() to swab() and share globally in swab.h")
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> Cc: Yury Norov <yury.norov@gmail.com>
> Cc: Allison Randal <allison@lohutok.net>
> Cc: Joe Perches <joe@perches.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
> Cc: Torsten Hilbrich <torsten.hilbrich@secunet.com>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
> (cherry picked from commit 467d12f5c7842896d2de3ced74e4147ee29e97c8)

As you are passing on patches from others, it is usually requried that
you too sign-off on them.  Can you fix that up on this series and resend
it so that I can take them?

thanks,

greg k-h

Re: [v4.9 PATCH 1/6] include/uapi/linux/swab.h: fix userspace breakage, use __BITS_PER_LONG for swap

[Hans-Christian Egtvedt (hegtvedt)]

On 01/08/2022 13:09, Greg KH wrote:
> On Sun, Jul 31, 2022 at 08:26:31PM +0200, Hans-Christian Noren Egtvedt wrote:
>> From: Christian Borntraeger <borntraeger@de.ibm.com>
>>
>> QEMU has a funny new build error message when I use the upstream kernel
>> headers:
>>
>>       CC      block/file-posix.o
>>     In file included from /home/cborntra/REPOS/qemu/include/qemu/timer.h:4,
>>                      from /home/cborntra/REPOS/qemu/include/qemu/timed-average.h:29,
>>                      from /home/cborntra/REPOS/qemu/include/block/accounting.h:28,
>>                      from /home/cborntra/REPOS/qemu/include/block/block_int.h:27,
>>                      from /home/cborntra/REPOS/qemu/block/file-posix.c:30:
>>     /usr/include/linux/swab.h: In function `__swab':
>>     /home/cborntra/REPOS/qemu/include/qemu/bitops.h:20:34: error: "sizeof" is not defined, evaluates to 0 [-Werror=undef]
>>        20 | #define BITS_PER_LONG           (sizeof (unsigned long) * BITS_PER_BYTE)
>>           |                                  ^~~~~~
>>     /home/cborntra/REPOS/qemu/include/qemu/bitops.h:20:41: error: missing binary operator before token "("
>>        20 | #define BITS_PER_LONG           (sizeof (unsigned long) * BITS_PER_BYTE)
>>           |                                         ^
>>     cc1: all warnings being treated as errors
>>     make: *** [/home/cborntra/REPOS/qemu/rules.mak:69: block/file-posix.o] Error 1
>>     rm tests/qemu-iotests/socket_scm_helper.o
>>
>> This was triggered by commit d5767057c9a ("uapi: rename ext2_swab() to
>> swab() and share globally in swab.h").  That patch is doing
>>
>>   #include <asm/bitsperlong.h>
>>
>> but it uses BITS_PER_LONG.
>>
>> The kernel file asm/bitsperlong.h provide only __BITS_PER_LONG.
>>
>> Let us use the __ variant in swap.h
>>
>> Link: http://lkml.kernel.org/r/20200213142147.17604-1-borntraeger@de.ibm.com
>> Fixes: d5767057c9a ("uapi: rename ext2_swab() to swab() and share globally in swab.h")
>> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
>> Cc: Yury Norov <yury.norov@gmail.com>
>> Cc: Allison Randal <allison@lohutok.net>
>> Cc: Joe Perches <joe@perches.com>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
>> Cc: Torsten Hilbrich <torsten.hilbrich@secunet.com>
>> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
>> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
>> (cherry picked from commit 467d12f5c7842896d2de3ced74e4147ee29e97c8)
> 
> As you are passing on patches from others, it is usually requried that
> you too sign-off on them.  Can you fix that up on this series and resend
> it so that I can take them?

Yes, sorry, we do not add signed-off-by entries internally, so my git
config does not add it by default. Will resend the series.

-- 
Best regards, Hans-Christian Noren Egtvedt

Re: [v4.9 PATCH 1/6] include/uapi/linux/swab.h: fix userspace breakage, use __BITS_PER_LONG for swap

[Greg KH]

On Mon, Aug 01, 2022 at 04:33:16PM +0000, Hans-Christian Egtvedt (hegtvedt) wrote:
> On 01/08/2022 13:09, Greg KH wrote:
> > As you are passing on patches from others, it is usually requried that
> > you too sign-off on them.  Can you fix that up on this series and resend
> > it so that I can take them?
> 
> Yes, sorry, we do not add signed-off-by entries internally, so my git
> config does not add it by default. Will resend the series.

You really should do this internally as well, that way you have a "path
of blame" to help keep track of why patches were added to your trees,
and who did the reviewing of them.

I'll go pick up the resent series now, thanks.

greg k-h

[v4.9 PATCH 2/6] init/main: Fix double "the" in comment

[Hans-Christian Noren Egtvedt]

From: Viresh Kumar <viresh.kumar@linaro.org>

s/the\ the/the

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
(cherry picked from commit 6623f1c6150c09ce946c8e27a4c814d64919495b)
---
 init/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/init/main.c b/init/main.c
index 30226a836c8..a6ecdd492ed 100644
--- a/init/main.c
+++ b/init/main.c
@@ -488,7 +488,7 @@ asmlinkage __visible void __init start_kernel(void)
 	debug_objects_early_init();
 
 	/*
-	 * Set up the the initial canary ASAP:
+	 * Set up the initial canary ASAP:
 	 */
 	add_latent_entropy();
 	boot_init_stack_canary();
-- 
2.34.1

[v4.9 PATCH 3/6] init/main: properly align the multi-line comment

[Hans-Christian Noren Egtvedt]

From: Viresh Kumar <viresh.kumar@linaro.org>

Add a tab before it to follow standard practices. Also add the missing
full stop '.'.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
(cherry picked from commit 1b3b3b49b9961401331a1b496db5bec5c7b41ae6)
---
 init/main.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/init/main.c b/init/main.c
index a6ecdd492ed..8b803078d7b 100644
--- a/init/main.c
+++ b/init/main.c
@@ -498,10 +498,10 @@ asmlinkage __visible void __init start_kernel(void)
 	local_irq_disable();
 	early_boot_irqs_disabled = true;
 
-/*
- * Interrupts are still disabled. Do necessary setups, then
- * enable them
- */
+	/*
+	 * Interrupts are still disabled. Do necessary setups, then
+	 * enable them.
+	 */
 	boot_cpu_init();
 	page_address_init();
 	pr_notice("%s", linux_banner);
-- 
2.34.1

[v4.9 PATCH 4/6] init: move stack canary initialization after setup_arch

[Hans-Christian Noren Egtvedt]

From: Laura Abbott <lauraa@codeaurora.org>

Patch series "Command line randomness", v3.

A series to add the kernel command line as a source of randomness.

This patch (of 2):

Stack canary intialization involves getting a random number.  Getting this
random number may involve accessing caches or other architectural specific
features which are not available until after the architecture is setup.
Move the stack canary initialization later to accommodate this.

Link: http://lkml.kernel.org/r/20170816231458.2299-2-labbott@redhat.com
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: Nick Kralevich <nnk@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 121388a31362b0d3176dc1190ac8064b98a61b20)
---
 init/main.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/init/main.c b/init/main.c
index 8b803078d7b..67fa94c5967 100644
--- a/init/main.c
+++ b/init/main.c
@@ -487,12 +487,6 @@ asmlinkage __visible void __init start_kernel(void)
 	smp_setup_processor_id();
 	debug_objects_early_init();
 
-	/*
-	 * Set up the initial canary ASAP:
-	 */
-	add_latent_entropy();
-	boot_init_stack_canary();
-
 	cgroup_init_early();
 
 	local_irq_disable();
@@ -506,6 +500,11 @@ asmlinkage __visible void __init start_kernel(void)
 	page_address_init();
 	pr_notice("%s", linux_banner);
 	setup_arch(&command_line);
+	/*
+	 * Set up the the initial canary and entropy after arch
+	 */
+	add_latent_entropy();
+	boot_init_stack_canary();
 	mm_init_cpumask(&init_mm);
 	setup_command_line(command_line);
 	setup_nr_cpu_ids();
-- 
2.34.1

[v4.9 PATCH 5/6] init/main.c: extract early boot entropy from the passed cmdline

[Hans-Christian Noren Egtvedt]

From: Daniel Micay <danielmicay@gmail.com>

Feed the boot command-line as to the /dev/random entropy pool

Existing Android bootloaders usually pass data which may not be known by
an external attacker on the kernel command-line.  It may also be the
case on other embedded systems.  Sample command-line from a Google Pixel
running CopperheadOS....

    console=ttyHSL0,115200,n8 androidboot.console=ttyHSL0
    androidboot.hardware=sailfish user_debug=31 ehci-hcd.park=3
    lpm_levels.sleep_disabled=1 cma=32M@0-0xffffffff buildvariant=user
    veritykeyid=id:dfcb9db0089e5b3b4090a592415c28e1cb4545ab
    androidboot.bootdevice=624000.ufshc androidboot.verifiedbootstate=yellow
    androidboot.veritymode=enforcing androidboot.keymaster=1
    androidboot.serialno=FA6CE0305299 androidboot.baseband=msm
    mdss_mdp.panel=1:dsi:0:qcom,mdss_dsi_samsung_ea8064tg_1080p_cmd:1:none:cfg:single_dsi
    androidboot.slot_suffix=_b fpsimd.fpsimd_settings=0
    app_setting.use_app_setting=0 kernelflag=0x00000000 debugflag=0x00000000
    androidboot.hardware.revision=PVT radioflag=0x00000000
    radioflagex1=0x00000000 radioflagex2=0x00000000 cpumask=0x00000000
    androidboot.hardware.ddr=4096MB,Hynix,LPDDR4 androidboot.ddrinfo=00000006
    androidboot.ddrsize=4GB androidboot.hardware.color=GRA00
    androidboot.hardware.ufs=32GB,Samsung androidboot.msm.hw_ver_id=268824801
    androidboot.qf.st=2 androidboot.cid=11111111 androidboot.mid=G-2PW4100
    androidboot.bootloader=8996-012001-1704121145
    androidboot.oem_unlock_support=1 androidboot.fp_src=1
    androidboot.htc.hrdump=detected androidboot.ramdump.opt=mem@2g:2g,mem@4g:2g
    androidboot.bootreason=reboot androidboot.ramdump_enable=0 ro
    root=/dev/dm-0 dm="system none ro,0 1 android-verity /dev/sda34"
    rootwait skip_initramfs init=/init androidboot.wificountrycode=US
    androidboot.boottime=1BLL:85,1BLE:669,2BLL:0,2BLE:1777,SW:6,KL:8136

Among other things, it contains a value unique to the device
(androidboot.serialno=FA6CE0305299), unique to the OS builds for the
device variant (veritykeyid=id:dfcb9db0089e5b3b4090a592415c28e1cb4545ab)
and timings from the bootloader stages in milliseconds
(androidboot.boottime=1BLL:85,1BLE:669,2BLL:0,2BLE:1777,SW:6,KL:8136).

[tytso@mit.edu: changelog tweak]
[labbott@redhat.com: line-wrapped command line]
Link: http://lkml.kernel.org/r/20170816231458.2299-3-labbott@redhat.com
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Nick Kralevich <nnk@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 33d72f3822d7ff8a9e45bd7413c811085cb87aa5)
---
 init/main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/init/main.c b/init/main.c
index 67fa94c5967..6bc1a3fa152 100644
--- a/init/main.c
+++ b/init/main.c
@@ -502,8 +502,10 @@ asmlinkage __visible void __init start_kernel(void)
 	setup_arch(&command_line);
 	/*
 	 * Set up the the initial canary and entropy after arch
+	 * and after adding latent and command line entropy.
 	 */
 	add_latent_entropy();
+	add_device_randomness(command_line, strlen(command_line));
 	boot_init_stack_canary();
 	mm_init_cpumask(&init_mm);
 	setup_command_line(command_line);
-- 
2.34.1

[v4.9 PATCH 6/6] random: move rand_initialize() earlier

[Hans-Christian Noren Egtvedt]

From: Kees Cook <keescook@chromium.org>

Right now rand_initialize() is run as an early_initcall(), but it only
depends on timekeeping_init() (for mixing ktime_get_real() into the
pools). However, the call to boot_init_stack_canary() for stack canary
initialization runs earlier, which triggers a warning at boot:

random: get_random_bytes called from start_kernel+0x357/0x548 with crng_init=0

Instead, this moves rand_initialize() to after timekeeping_init(), and moves
canary initialization here as well.

Note that this warning may still remain for machines that do not have
UEFI RNG support (which initializes the RNG pools during setup_arch()),
or for x86 machines without RDRAND (or booting without "random.trust=on"
or CONFIG_RANDOM_TRUST_CPU=y).

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
(cherry picked from commit d55535232c3dbde9a523a9d10d68670f5fe5dec3)

Adjusted to fit on top of linux-4.9.y branch, suspecting a wrongly
solved conflict when cherry picked earlier.
---
 init/main.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/init/main.c b/init/main.c
index 6bc1a3fa152..6537f51a0ba 100644
--- a/init/main.c
+++ b/init/main.c
@@ -500,13 +500,6 @@ asmlinkage __visible void __init start_kernel(void)
 	page_address_init();
 	pr_notice("%s", linux_banner);
 	setup_arch(&command_line);
-	/*
-	 * Set up the the initial canary and entropy after arch
-	 * and after adding latent and command line entropy.
-	 */
-	add_latent_entropy();
-	add_device_randomness(command_line, strlen(command_line));
-	boot_init_stack_canary();
 	mm_init_cpumask(&init_mm);
 	setup_command_line(command_line);
 	setup_nr_cpu_ids();
-- 
2.34.1