Re: [PATCH v2 7/9] lib/vsprintf: Replace space with '_' before crng is ready

[Petr Mladek]

On Fri 2018-02-16 23:07:09, Andy Shevchenko wrote:
> From: Shunyong Yang 
> 
> Before crng is ready, output of "%p" composes of "(ptrval)" and
> left padding spaces for alignment as no random address can be
> generated. This seems a little strange when default string width
> is larger than strlen("(ptrval)").
> 
> For example, when irq domain names are built with "%p", the nodes
> under /sys/kernel/debug/irq/domains like this on AArch64 system,
> 
> [root@y irq]# ls domains/
> default   irqchip@(ptrval)-2
> irqchip@(ptrval)-4  \_SB_.TCS0.QIC1  \_SB_.TCS0.QIC3
> irqchip@(ptrval)  irqchip@(ptrval)-3
> \_SB_.TCS0.QIC0 \_SB_.TCS0.QIC2
> 
> The name "irqchip@(ptrval)-2" is not so readable in console
> output.
> 
> This patch replaces space with readable "_" when output needs padding.
> Following is the output after applying the patch,
> 
> [root@y domains]# ls
> default   irqchip@(ptrval)-2
> irqchip@(ptrval)-4  \_SB_.TCS0.QIC1  \_SB_.TCS0.QIC3
> irqchip@(ptrval)  irqchip@(ptrval)-3  \_SB_.TCS0.QIC0
> \_SB_.TCS0.QIC2
> 
> There is same problem in some subsystem's dmesg output. Moreover,
> someone may call "%p" in a similar case. In addition, the timing of
> crng initialization done may vary on different system. So, the change
> is made in vsprintf.c.
> 
> Cc: Joey Zheng 
> Suggested-by: Rasmus Villemoes 
> Signed-off-by: Shunyong Yang 
> Signed-off-by: Andy Shevchenko 

Reviewed-by: Petr Mladek 

I have pushed it into printk.git, branch for-4.18-vsprintf-cleanup.

Best Regards,
Petr

Re: [PATCH v2 7/9] lib/vsprintf: Replace space with '_' before crng is ready

[Petr Mladek]

On Fri 2018-02-16 23:07:09, Andy Shevchenko wrote:
> From: Shunyong Yang 
> 
> Before crng is ready, output of "%p" composes of "(ptrval)" and
> left padding spaces for alignment as no random address can be
> generated. This seems a little strange when default string width
> is larger than strlen("(ptrval)").
> 
> For example, when irq domain names are built with "%p", the nodes
> under /sys/kernel/debug/irq/domains like this on AArch64 system,
> 
> [root@y irq]# ls domains/
> default   irqchip@(ptrval)-2
> irqchip@(ptrval)-4  \_SB_.TCS0.QIC1  \_SB_.TCS0.QIC3
> irqchip@(ptrval)  irqchip@(ptrval)-3
> \_SB_.TCS0.QIC0 \_SB_.TCS0.QIC2
> 
> The name "irqchip@(ptrval)-2" is not so readable in console
> output.
> 
> This patch replaces space with readable "_" when output needs padding.
> Following is the output after applying the patch,
> 
> [root@y domains]# ls
> default   irqchip@(ptrval)-2
> irqchip@(ptrval)-4  \_SB_.TCS0.QIC1  \_SB_.TCS0.QIC3
> irqchip@(ptrval)  irqchip@(ptrval)-3  \_SB_.TCS0.QIC0
> \_SB_.TCS0.QIC2
> 
> There is same problem in some subsystem's dmesg output. Moreover,
> someone may call "%p" in a similar case. In addition, the timing of
> crng initialization done may vary on different system. So, the change
> is made in vsprintf.c.
> 
> Cc: Joey Zheng 
> Suggested-by: Rasmus Villemoes 
> Signed-off-by: Shunyong Yang 
> Signed-off-by: Andy Shevchenko 

Reviewed-by: Petr Mladek 

I have pushed it into printk.git, branch for-4.18-vsprintf-cleanup.

Best Regards,
Petr

Re: [此邮件可能存在风险] [PATCH v2 7/9] lib/vsprintf: Replace space with '_' before crng is ready

[Yang, Shunyong]

Hi, Andy,

Many thanks for the change. I am on Chinese New Year travel and slow
response. :-)

Thanks.
Shunyong.

On Fri, 2018-02-16 at 23:07 +0200, Andy Shevchenko wrote:
> From: Shunyong Yang 
> 
> Before crng is ready, output of "%p" composes of "(ptrval)" and
> left padding spaces for alignment as no random address can be
> generated. This seems a little strange when default string width
> is larger than strlen("(ptrval)").
> 
> For example, when irq domain names are built with "%p", the nodes
> under /sys/kernel/debug/irq/domains like this on AArch64 system,
> 
> [root@y irq]# ls domains/
> default   irqchip@(ptrval)-2
> irqchip@(ptrval)-4  \_SB_.TCS0.QIC1  \_SB_.TCS0.QIC3
> irqchip@(ptrval)  irqchip@(ptrval)-3
> \_SB_.TCS0.QIC0 \_SB_.TCS0.QIC2
> 
> The name "irqchip@(ptrval)-2" is not so readable in console
> output.
> 
> This patch replaces space with readable "_" when output needs
> padding.
> Following is the output after applying the patch,
> 
> [root@y domains]# ls
> default   irqchip@(ptrval)-2
> irqchip@(ptrval)-4  \_SB_.TCS0.QIC1  \_SB_.TCS0.QIC3
> irqchip@(ptrval)  irqchip@(ptrval)-3  \_SB_.TCS0.QIC0
> \_SB_.TCS0.QIC2
> 
> There is same problem in some subsystem's dmesg output. Moreover,
> someone may call "%p" in a similar case. In addition, the timing of
> crng initialization done may vary on different system. So, the change
> is made in vsprintf.c.
> 
> Cc: Joey Zheng 
> Suggested-by: Rasmus Villemoes 
> Signed-off-by: Shunyong Yang 
> Signed-off-by: Andy Shevchenko 
> ---
>  lib/vsprintf.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> index 9004bbb3d84d..97be2d07297a 100644
> --- a/lib/vsprintf.c
> +++ b/lib/vsprintf.c
> @@ -1681,12 +1681,13 @@ early_initcall(initialize_ptr_random);
>  /* Maps a pointer to a 32 bit unique identifier. */
>  static char *ptr_to_id(char *buf, char *end, void *ptr, struct
> printf_spec spec)
>  {
> + const char *str = sizeof(ptr) == 8 ? "(ptrval)" :
> "(ptrval)";
>   unsigned long hashval;
>  
>   if (unlikely(!have_filled_random_ptr_key)) {
>   spec.field_width = 2 * sizeof(ptr);
>   /* string length must be less than default_width */
> - return string(buf, end, "(ptrval)", spec);
> + return string(buf, end, str, spec);
>   }
>  
>  #ifdef CONFIG_64BIT

Re: [此邮件可能存在风险] [PATCH v2 7/9] lib/vsprintf: Replace space with '_' before crng is ready

[Yang, Shunyong]

Hi, Andy,

Many thanks for the change. I am on Chinese New Year travel and slow
response. :-)

Thanks.
Shunyong.

On Fri, 2018-02-16 at 23:07 +0200, Andy Shevchenko wrote:
> From: Shunyong Yang 
> 
> Before crng is ready, output of "%p" composes of "(ptrval)" and
> left padding spaces for alignment as no random address can be
> generated. This seems a little strange when default string width
> is larger than strlen("(ptrval)").
> 
> For example, when irq domain names are built with "%p", the nodes
> under /sys/kernel/debug/irq/domains like this on AArch64 system,
> 
> [root@y irq]# ls domains/
> default   irqchip@(ptrval)-2
> irqchip@(ptrval)-4  \_SB_.TCS0.QIC1  \_SB_.TCS0.QIC3
> irqchip@(ptrval)  irqchip@(ptrval)-3
> \_SB_.TCS0.QIC0 \_SB_.TCS0.QIC2
> 
> The name "irqchip@(ptrval)-2" is not so readable in console
> output.
> 
> This patch replaces space with readable "_" when output needs
> padding.
> Following is the output after applying the patch,
> 
> [root@y domains]# ls
> default   irqchip@(ptrval)-2
> irqchip@(ptrval)-4  \_SB_.TCS0.QIC1  \_SB_.TCS0.QIC3
> irqchip@(ptrval)  irqchip@(ptrval)-3  \_SB_.TCS0.QIC0
> \_SB_.TCS0.QIC2
> 
> There is same problem in some subsystem's dmesg output. Moreover,
> someone may call "%p" in a similar case. In addition, the timing of
> crng initialization done may vary on different system. So, the change
> is made in vsprintf.c.
> 
> Cc: Joey Zheng 
> Suggested-by: Rasmus Villemoes 
> Signed-off-by: Shunyong Yang 
> Signed-off-by: Andy Shevchenko 
> ---
>  lib/vsprintf.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
> index 9004bbb3d84d..97be2d07297a 100644
> --- a/lib/vsprintf.c
> +++ b/lib/vsprintf.c
> @@ -1681,12 +1681,13 @@ early_initcall(initialize_ptr_random);
>  /* Maps a pointer to a 32 bit unique identifier. */
>  static char *ptr_to_id(char *buf, char *end, void *ptr, struct
> printf_spec spec)
>  {
> + const char *str = sizeof(ptr) == 8 ? "(ptrval)" :
> "(ptrval)";
>   unsigned long hashval;
>  
>   if (unlikely(!have_filled_random_ptr_key)) {
>   spec.field_width = 2 * sizeof(ptr);
>   /* string length must be less than default_width */
> - return string(buf, end, "(ptrval)", spec);
> + return string(buf, end, str, spec);
>   }
>  
>  #ifdef CONFIG_64BIT

[PATCH v2 7/9] lib/vsprintf: Replace space with '_' before crng is ready

[Andy Shevchenko]

From: Shunyong Yang 

Before crng is ready, output of "%p" composes of "(ptrval)" and
left padding spaces for alignment as no random address can be
generated. This seems a little strange when default string width
is larger than strlen("(ptrval)").

For example, when irq domain names are built with "%p", the nodes
under /sys/kernel/debug/irq/domains like this on AArch64 system,

[root@y irq]# ls domains/
default   irqchip@(ptrval)-2
irqchip@(ptrval)-4  \_SB_.TCS0.QIC1  \_SB_.TCS0.QIC3
irqchip@(ptrval)  irqchip@(ptrval)-3
\_SB_.TCS0.QIC0 \_SB_.TCS0.QIC2

The name "irqchip@(ptrval)-2" is not so readable in console
output.

This patch replaces space with readable "_" when output needs padding.
Following is the output after applying the patch,

[root@y domains]# ls
default   irqchip@(ptrval)-2
irqchip@(ptrval)-4  \_SB_.TCS0.QIC1  \_SB_.TCS0.QIC3
irqchip@(ptrval)  irqchip@(ptrval)-3  \_SB_.TCS0.QIC0
\_SB_.TCS0.QIC2

There is same problem in some subsystem's dmesg output. Moreover,
someone may call "%p" in a similar case. In addition, the timing of
crng initialization done may vary on different system. So, the change
is made in vsprintf.c.

Cc: Joey Zheng 
Suggested-by: Rasmus Villemoes 
Signed-off-by: Shunyong Yang 
Signed-off-by: Andy Shevchenko 
---
 lib/vsprintf.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 9004bbb3d84d..97be2d07297a 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1681,12 +1681,13 @@ early_initcall(initialize_ptr_random);
 /* Maps a pointer to a 32 bit unique identifier. */
 static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec 
spec)
 {
+   const char *str = sizeof(ptr) == 8 ? "(ptrval)" : "(ptrval)";
unsigned long hashval;
 
if (unlikely(!have_filled_random_ptr_key)) {
spec.field_width = 2 * sizeof(ptr);
/* string length must be less than default_width */
-   return string(buf, end, "(ptrval)", spec);
+   return string(buf, end, str, spec);
}
 
 #ifdef CONFIG_64BIT
-- 
2.15.1

[PATCH v2 7/9] lib/vsprintf: Replace space with '_' before crng is ready

[Andy Shevchenko]

From: Shunyong Yang 

Before crng is ready, output of "%p" composes of "(ptrval)" and
left padding spaces for alignment as no random address can be
generated. This seems a little strange when default string width
is larger than strlen("(ptrval)").

For example, when irq domain names are built with "%p", the nodes
under /sys/kernel/debug/irq/domains like this on AArch64 system,

[root@y irq]# ls domains/
default   irqchip@(ptrval)-2
irqchip@(ptrval)-4  \_SB_.TCS0.QIC1  \_SB_.TCS0.QIC3
irqchip@(ptrval)  irqchip@(ptrval)-3
\_SB_.TCS0.QIC0 \_SB_.TCS0.QIC2

The name "irqchip@(ptrval)-2" is not so readable in console
output.

This patch replaces space with readable "_" when output needs padding.
Following is the output after applying the patch,

[root@y domains]# ls
default   irqchip@(ptrval)-2
irqchip@(ptrval)-4  \_SB_.TCS0.QIC1  \_SB_.TCS0.QIC3
irqchip@(ptrval)  irqchip@(ptrval)-3  \_SB_.TCS0.QIC0
\_SB_.TCS0.QIC2

There is same problem in some subsystem's dmesg output. Moreover,
someone may call "%p" in a similar case. In addition, the timing of
crng initialization done may vary on different system. So, the change
is made in vsprintf.c.

Cc: Joey Zheng 
Suggested-by: Rasmus Villemoes 
Signed-off-by: Shunyong Yang 
Signed-off-by: Andy Shevchenko 
---
 lib/vsprintf.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 9004bbb3d84d..97be2d07297a 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1681,12 +1681,13 @@ early_initcall(initialize_ptr_random);
 /* Maps a pointer to a 32 bit unique identifier. */
 static char *ptr_to_id(char *buf, char *end, void *ptr, struct printf_spec 
spec)
 {
+   const char *str = sizeof(ptr) == 8 ? "(ptrval)" : "(ptrval)";
unsigned long hashval;
 
if (unlikely(!have_filled_random_ptr_key)) {
spec.field_width = 2 * sizeof(ptr);
/* string length must be less than default_width */
-   return string(buf, end, "(ptrval)", spec);
+   return string(buf, end, str, spec);
}
 
 #ifdef CONFIG_64BIT
-- 
2.15.1