Re: [RFC 1/2] ARC: U-boot: check arguments paranoidly

2019-02-06 Thread Vineet Gupta
On 2/6/19 9:22 AM, Eugeniy Paltsev wrote:
> Handle U-boot arguments paranoidly:
>  * don't allow to pass unknown tag.
>  * try to use external device tree blob only if corresponding tag
>(TAG_DTB) is set.
>  * don't check: uboot_tag if kernel build with no ARC_UBOOT_SUPPORT.
> 
> While I'm at it refactor U-boot arguments handling code.
> 
> Signed-off-by: Eugeniy Paltsev 
> ---
>  arch/arc/kernel/head.S  |  2 +-
>  arch/arc/kernel/setup.c | 65 
> -
>  2 files changed, 44 insertions(+), 23 deletions(-)
> 
> diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
> index 8b90d25a15cc..7095055bb874 100644
> --- a/arch/arc/kernel/head.S
> +++ b/arch/arc/kernel/head.S
> @@ -95,7 +95,7 @@ ENTRY(stext)
>   ;r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2
>   ;r1 = magic number (board identity, unused as of now
>   ;r2 = pointer to uboot provided cmdline or external DTB in mem
> - ; These are handled later in setup_arch()
> + ; These are handled later in handle_uboot_args()
>   st  r0, [@uboot_tag]
>   st  r2, [@uboot_arg]
>  #endif
> diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
> index feb90093e6b1..7edb35c26322 100644
> --- a/arch/arc/kernel/setup.c
> +++ b/arch/arc/kernel/setup.c
> @@ -462,43 +462,64 @@ void setup_processor(void)
>   arc_chk_core_config();
>  }
>  
> -static inline int is_kernel(unsigned long addr)
> +static inline bool is_kernel(unsigned long addr)
>  {
> - if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
> - return 1;
> - return 0;
> + return addr >= (unsigned long)_stext && addr <= (unsigned long)_end;
>  }
>  
> -void __init setup_arch(char **cmdline_p)
> +/* uboot_tag values for U-boot - kernel ABI revisions 0+; see head.S */
> +#define UBOOT_REV0P_TAG_NONE 0
> +#define UBOOT_REV0P_TAG_CMDLINE  1
> +#define UBOOT_REV0P_TAG_DTB  2
> +
> +void __init handle_uboot_args(void)
>  {
> + bool append_boot_cmdline = false;
> + bool use_embedded_dtb = true;
> +
>  #ifdef CONFIG_ARC_UBOOT_SUPPORT
> + /* check that we know this tag */
> + if (uboot_tag != UBOOT_REV0P_TAG_NONE &&
> + uboot_tag != UBOOT_REV0P_TAG_CMDLINE &&
> + uboot_tag != UBOOT_REV0P_TAG_DTB)
> + panic("Invalid uboot tag: '%08x'\n", uboot_tag);
> +
>   /* make sure that uboot passed pointer to cmdline/dtb is valid */
> - if (uboot_tag && is_kernel((unsigned long)uboot_arg))
> + if (uboot_tag != UBOOT_REV0P_TAG_NONE && is_kernel((unsigned 
> long)uboot_arg))
>   panic("Invalid uboot arg\n");
>  
>   /* See if u-boot passed an external Device Tree blob */
> - machine_desc = setup_machine_fdt(uboot_arg);/* uboot_tag == 2 */
> - if (!machine_desc)
> + if (uboot_tag == UBOOT_REV0P_TAG_DTB) {
> + machine_desc = setup_machine_fdt(uboot_arg);
> +
> + /* external Device Tree blob is invalid - use embedded one */
> + use_embedded_dtb = !machine_desc;
> + }
> +
> + if (uboot_tag == UBOOT_REV0P_TAG_CMDLINE)
> + append_boot_cmdline = true;
>  #endif
> - {
> - /* No, so try the embedded one */
> +
> + if (use_embedded_dtb) {
>   machine_desc = setup_machine_fdt(__dtb_start);
>   if (!machine_desc)
>   panic("Embedded DT invalid\n");
> + }
>  
> - /*
> -  * If we are here, it is established that @uboot_arg didn't
> -  * point to DT blob. Instead if u-boot says it is cmdline,
> -  * append to embedded DT cmdline.
> -  * setup_machine_fdt() would have populated @boot_command_line
> -  */
> - if (uboot_tag == 1) {
> - /* Ensure a whitespace between the 2 cmdlines */
> - strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
> - strlcat(boot_command_line, uboot_arg,
> - COMMAND_LINE_SIZE);
> - }
> + /*
> +  * If we are here, U-boot says that @uboot_arg is cmdline, so append it
> +  * to embedded DT cmdline.
> +  */
> + if (append_boot_cmdline) {
> + /* Ensure a whitespace between the 2 cmdlines */
> + strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
> + strlcat(boot_command_line, uboot_arg, COMMAND_LINE_SIZE);
>   }
> +}
> +
> +void __init setup_arch(char **cmdline_p)
> +{
> + handle_uboot_args();
>  
>   /* Save unparsed command line copy for /proc/cmdline */
>   *cmdline_p = boot_command_line;

I think we can grossly simplify all of this w/o adding any new ABI contract
between kernel and uboot and eliminate CONFIG_ARC_UBOOT_SUPPORT as well (make
uboot support always enabled)

So when bootloader runs it passes {0,1,2} in r0 and corresponding arg in r2.
For jtag case we can assume that 

Re: [RFC 2/2] ARC: U-boot: check magic number passed from u-boot

2019-02-06 Thread Vineet Gupta
On 2/6/19 9:22 AM, Eugeniy Paltsev wrote:
> In case of devboards we really often disable bootloader and load
> Linux image in memory via JTAG. In case of using kernel with
> CONFIG_ARC_UBOOT_SUPPORT enabled we may crash as we will try to
> interpret some junk in a registers as a pointers to bootargs/etc
> which aren't set by anyone in case of JTAG using.
> 
> Try to make it much less possible by check magic number and
> 'U-boot - kernel' ABI revision number passed from U-boot.
> Ignore U-boot arguments if we got wrong magic number or unknown
> ABI revision.
> 
> Signed-off-by: Eugeniy Paltsev 
> ---
>  arch/arc/kernel/head.S  |  5 -
>  arch/arc/kernel/setup.c | 26 ++
>  2 files changed, 30 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
> index 7095055bb874..3fb88ec62bc7 100644
> --- a/arch/arc/kernel/head.S
> +++ b/arch/arc/kernel/head.S
> @@ -92,10 +92,13 @@ ENTRY(stext)
>  
>  #ifdef CONFIG_ARC_UBOOT_SUPPORT
>   ; Uboot - kernel ABI
> + ;r1 = bits [31:8] magic number, bits [7:0] uboot-kernel ABI revision
> + ; ABI revision 0:
>   ;r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2
> - ;r1 = magic number (board identity, unused as of now
>   ;r2 = pointer to uboot provided cmdline or external DTB in mem
>   ; These are handled later in handle_uboot_args()
> + st  r1, [@uboot_rev_magic]
> + mov r1, 0   ; errase magic from the register
>   st  r0, [@uboot_tag]
>   st  r2, [@uboot_arg]
>  #endif
> diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
> index 7edb35c26322..868dda3d4b43 100644
> --- a/arch/arc/kernel/setup.c
> +++ b/arch/arc/kernel/setup.c
> @@ -36,6 +36,7 @@ unsigned int intr_to_DE_cnt;
>  
>  /* Part of U-boot ABI: see head.S */
>  int __initdata uboot_tag;
> +int __initdata uboot_rev_magic;
>  char __initdata *uboot_arg;
>  
>  const struct machine_desc *machine_desc;
> @@ -467,6 +468,10 @@ static inline bool is_kernel(unsigned long addr)
>   return addr >= (unsigned long)_stext && addr <= (unsigned long)_end;
>  }
>  
> +#define UBOOT_MAGIC_VALUE0x567890
> +#define UBOOT_MAGIC_GET(x)   (((x) & GENMASK(31, 8)) >> 8)
> +#define UBOOT_REVISION_GET(x)((x) & GENMASK(7, 0))
> +
>  /* uboot_tag values for U-boot - kernel ABI revisions 0+; see head.S */
>  #define UBOOT_REV0P_TAG_NONE 0
>  #define UBOOT_REV0P_TAG_CMDLINE  1
> @@ -478,6 +483,25 @@ void __init handle_uboot_args(void)
>   bool use_embedded_dtb = true;
>  
>  #ifdef CONFIG_ARC_UBOOT_SUPPORT
> + /* check that we got correct magic */
> + if (UBOOT_MAGIC_GET(uboot_rev_magic) != UBOOT_MAGIC_VALUE) {
> + pr_warn("Invalid magic '%06lx' is passed from uboot, uboot args 
> ingnored\n",
> + UBOOT_MAGIC_GET(uboot_rev_magic));
> +
> + goto ignore_uboot_args;
> + }
> +
> + /*
> +  * check that we know this U-boot args ABI revision.
> +  * as for today we only have one revision - '0'.
> +  */
> + if (UBOOT_REVISION_GET(uboot_rev_magic) != 0) {
> + pr_warn("Unknown args revision '%02lx' is passed from uboot, 
> uboot args ingnored\n",
> + UBOOT_REVISION_GET(uboot_rev_magic));
> +
> + goto ignore_uboot_args;
> + }
> +

So you are effectively dropping support for older uboot here as above seems to
assume that r1 will have the new magic value now. The existing stock of HSDK
boards will continue to ship with older uboot.

I understand your idea, but the fact is we can't drop the old uboot support.

Also not sure how all of this allows us to eliminate CONFIG_ARC_UBOOT_SUPPORT, 
or
enable it unconditionally with old or new uboot.


>   /* check that we know this tag */
>   if (uboot_tag != UBOOT_REV0P_TAG_NONE &&
>   uboot_tag != UBOOT_REV0P_TAG_CMDLINE &&
> @@ -498,6 +522,8 @@ void __init handle_uboot_args(void)
>  
>   if (uboot_tag == UBOOT_REV0P_TAG_CMDLINE)
>   append_boot_cmdline = true;
> +
> +ignore_uboot_args:
>  #endif
>  
>   if (use_embedded_dtb) {
> 


___
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc


Re: [RFC 1/2] ARC: U-boot: check arguments paranoidly

2019-02-06 Thread Vineet Gupta
On 2/6/19 9:22 AM, Eugeniy Paltsev wrote:
> Handle U-boot arguments paranoidly:
>  * don't allow to pass unknown tag.
>  * try to use external device tree blob only if corresponding tag
>(TAG_DTB) is set.
>  * don't check: uboot_tag if kernel build with no ARC_UBOOT_SUPPORT.
> 
> While I'm at it refactor U-boot arguments handling code.
> 
> Signed-off-by: Eugeniy Paltsev 
> ---
>  arch/arc/kernel/head.S  |  2 +-
>  arch/arc/kernel/setup.c | 65 
> -
>  2 files changed, 44 insertions(+), 23 deletions(-)
> 
> diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
> index 8b90d25a15cc..7095055bb874 100644
> --- a/arch/arc/kernel/head.S
> +++ b/arch/arc/kernel/head.S
> @@ -95,7 +95,7 @@ ENTRY(stext)
>   ;r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2
>   ;r1 = magic number (board identity, unused as of now
>   ;r2 = pointer to uboot provided cmdline or external DTB in mem
> - ; These are handled later in setup_arch()
> + ; These are handled later in handle_uboot_args()
>   st  r0, [@uboot_tag]
>   st  r2, [@uboot_arg]
>  #endif
> diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
> index feb90093e6b1..7edb35c26322 100644
> --- a/arch/arc/kernel/setup.c
> +++ b/arch/arc/kernel/setup.c
> @@ -462,43 +462,64 @@ void setup_processor(void)
>   arc_chk_core_config();
>  }
>  
> -static inline int is_kernel(unsigned long addr)
> +static inline bool is_kernel(unsigned long addr)
>  {
> - if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
> - return 1;
> - return 0;

So even though I wrote it eons ago I was confused myself. We panic if this is 1,
because this addr seems inside kernel's resident image (code/data). So add that
comment maybe.

> + return addr >= (unsigned long)_stext && addr <= (unsigned long)_end;
>  }
>  
> -void __init setup_arch(char **cmdline_p)
> +/* uboot_tag values for U-boot - kernel ABI revisions 0+; see head.S */

Just call it ABI 0, and we call the new ABI 1.

> +#define UBOOT_REV0P_TAG_NONE 0
> +#define UBOOT_REV0P_TAG_CMDLINE  1
> +#define UBOOT_REV0P_TAG_DTB  2
> +
> +void __init handle_uboot_args(void)
>  {
> + bool append_boot_cmdline = false;
> + bool use_embedded_dtb = true;
> +
>  #ifdef CONFIG_ARC_UBOOT_SUPPORT
> + /* check that we know this tag */
> + if (uboot_tag != UBOOT_REV0P_TAG_NONE &&
> + uboot_tag != UBOOT_REV0P_TAG_CMDLINE &&
> + uboot_tag != UBOOT_REV0P_TAG_DTB)
> + panic("Invalid uboot tag: '%08x'\n", uboot_tag);
> +
>   /* make sure that uboot passed pointer to cmdline/dtb is valid */
> - if (uboot_tag && is_kernel((unsigned long)uboot_arg))
> + if (uboot_tag != UBOOT_REV0P_TAG_NONE && is_kernel((unsigned 
> long)uboot_arg))
>   panic("Invalid uboot arg\n");
>  
>   /* See if u-boot passed an external Device Tree blob */
> - machine_desc = setup_machine_fdt(uboot_arg);/* uboot_tag == 2 */
> - if (!machine_desc)
> + if (uboot_tag == UBOOT_REV0P_TAG_DTB) {
> + machine_desc = setup_machine_fdt(uboot_arg);
> +
> + /* external Device Tree blob is invalid - use embedded one */
> + use_embedded_dtb = !machine_desc;
> + }
> +
> + if (uboot_tag == UBOOT_REV0P_TAG_CMDLINE)
> + append_boot_cmdline = true;
>  #endif
> - {
> - /* No, so try the embedded one */
> +
> + if (use_embedded_dtb) {
>   machine_desc = setup_machine_fdt(__dtb_start);
>   if (!machine_desc)
>   panic("Embedded DT invalid\n");
> + }
>  
> - /*
> -  * If we are here, it is established that @uboot_arg didn't
> -  * point to DT blob. Instead if u-boot says it is cmdline,
> -  * append to embedded DT cmdline.
> -  * setup_machine_fdt() would have populated @boot_command_line
> -  */
> - if (uboot_tag == 1) {
> - /* Ensure a whitespace between the 2 cmdlines */
> - strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
> - strlcat(boot_command_line, uboot_arg,
> - COMMAND_LINE_SIZE);
> - }
> + /*
> +  * If we are here, U-boot says that @uboot_arg is cmdline, so append it
> +  * to embedded DT cmdline.
> +  */

This comment is useless after the more descriptive variable names.

> + if (append_boot_cmdline) {
> + /* Ensure a whitespace between the 2 cmdlines */
> + strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
> + strlcat(boot_command_line, uboot_arg, COMMAND_LINE_SIZE);
>   }
> +}
> +
> +void __init setup_arch(char **cmdline_p)
> +{
> + handle_uboot_args();
>  
>   /* Save unparsed command line copy for /proc/cmdline */
>   *cmdline_p = boot_command_line;

[RFC 0/2] ARC: rework U-boot arguments handling

2019-02-06 Thread Eugeniy Paltsev
Eugeniy Paltsev (2):
  ARC: U-boot: check arguments paranoidly
  ARC: U-boot: check magic number passed from u-boot

 arch/arc/kernel/head.S  |  7 ++--
 arch/arc/kernel/setup.c | 91 +
 2 files changed, 74 insertions(+), 24 deletions(-)

-- 
2.14.5

___
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc


[RFC 2/2] ARC: U-boot: check magic number passed from u-boot

2019-02-06 Thread Eugeniy Paltsev
In case of devboards we really often disable bootloader and load
Linux image in memory via JTAG. In case of using kernel with
CONFIG_ARC_UBOOT_SUPPORT enabled we may crash as we will try to
interpret some junk in a registers as a pointers to bootargs/etc
which aren't set by anyone in case of JTAG using.

Try to make it much less possible by check magic number and
'U-boot - kernel' ABI revision number passed from U-boot.
Ignore U-boot arguments if we got wrong magic number or unknown
ABI revision.

Signed-off-by: Eugeniy Paltsev 
---
 arch/arc/kernel/head.S  |  5 -
 arch/arc/kernel/setup.c | 26 ++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
index 7095055bb874..3fb88ec62bc7 100644
--- a/arch/arc/kernel/head.S
+++ b/arch/arc/kernel/head.S
@@ -92,10 +92,13 @@ ENTRY(stext)
 
 #ifdef CONFIG_ARC_UBOOT_SUPPORT
; Uboot - kernel ABI
+   ;r1 = bits [31:8] magic number, bits [7:0] uboot-kernel ABI revision
+   ; ABI revision 0:
;r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2
-   ;r1 = magic number (board identity, unused as of now
;r2 = pointer to uboot provided cmdline or external DTB in mem
; These are handled later in handle_uboot_args()
+   st  r1, [@uboot_rev_magic]
+   mov r1, 0   ; errase magic from the register
st  r0, [@uboot_tag]
st  r2, [@uboot_arg]
 #endif
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index 7edb35c26322..868dda3d4b43 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -36,6 +36,7 @@ unsigned int intr_to_DE_cnt;
 
 /* Part of U-boot ABI: see head.S */
 int __initdata uboot_tag;
+int __initdata uboot_rev_magic;
 char __initdata *uboot_arg;
 
 const struct machine_desc *machine_desc;
@@ -467,6 +468,10 @@ static inline bool is_kernel(unsigned long addr)
return addr >= (unsigned long)_stext && addr <= (unsigned long)_end;
 }
 
+#define UBOOT_MAGIC_VALUE  0x567890
+#define UBOOT_MAGIC_GET(x) (((x) & GENMASK(31, 8)) >> 8)
+#define UBOOT_REVISION_GET(x)  ((x) & GENMASK(7, 0))
+
 /* uboot_tag values for U-boot - kernel ABI revisions 0+; see head.S */
 #define UBOOT_REV0P_TAG_NONE   0
 #define UBOOT_REV0P_TAG_CMDLINE1
@@ -478,6 +483,25 @@ void __init handle_uboot_args(void)
bool use_embedded_dtb = true;
 
 #ifdef CONFIG_ARC_UBOOT_SUPPORT
+   /* check that we got correct magic */
+   if (UBOOT_MAGIC_GET(uboot_rev_magic) != UBOOT_MAGIC_VALUE) {
+   pr_warn("Invalid magic '%06lx' is passed from uboot, uboot args 
ingnored\n",
+   UBOOT_MAGIC_GET(uboot_rev_magic));
+
+   goto ignore_uboot_args;
+   }
+
+   /*
+* check that we know this U-boot args ABI revision.
+* as for today we only have one revision - '0'.
+*/
+   if (UBOOT_REVISION_GET(uboot_rev_magic) != 0) {
+   pr_warn("Unknown args revision '%02lx' is passed from uboot, 
uboot args ingnored\n",
+   UBOOT_REVISION_GET(uboot_rev_magic));
+
+   goto ignore_uboot_args;
+   }
+
/* check that we know this tag */
if (uboot_tag != UBOOT_REV0P_TAG_NONE &&
uboot_tag != UBOOT_REV0P_TAG_CMDLINE &&
@@ -498,6 +522,8 @@ void __init handle_uboot_args(void)
 
if (uboot_tag == UBOOT_REV0P_TAG_CMDLINE)
append_boot_cmdline = true;
+
+ignore_uboot_args:
 #endif
 
if (use_embedded_dtb) {
-- 
2.14.5


___
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc


[RFC 1/2] ARC: U-boot: check arguments paranoidly

2019-02-06 Thread Eugeniy Paltsev
Handle U-boot arguments paranoidly:
 * don't allow to pass unknown tag.
 * try to use external device tree blob only if corresponding tag
   (TAG_DTB) is set.
 * don't check: uboot_tag if kernel build with no ARC_UBOOT_SUPPORT.

While I'm at it refactor U-boot arguments handling code.

Signed-off-by: Eugeniy Paltsev 
---
 arch/arc/kernel/head.S  |  2 +-
 arch/arc/kernel/setup.c | 65 -
 2 files changed, 44 insertions(+), 23 deletions(-)

diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
index 8b90d25a15cc..7095055bb874 100644
--- a/arch/arc/kernel/head.S
+++ b/arch/arc/kernel/head.S
@@ -95,7 +95,7 @@ ENTRY(stext)
;r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2
;r1 = magic number (board identity, unused as of now
;r2 = pointer to uboot provided cmdline or external DTB in mem
-   ; These are handled later in setup_arch()
+   ; These are handled later in handle_uboot_args()
st  r0, [@uboot_tag]
st  r2, [@uboot_arg]
 #endif
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
index feb90093e6b1..7edb35c26322 100644
--- a/arch/arc/kernel/setup.c
+++ b/arch/arc/kernel/setup.c
@@ -462,43 +462,64 @@ void setup_processor(void)
arc_chk_core_config();
 }
 
-static inline int is_kernel(unsigned long addr)
+static inline bool is_kernel(unsigned long addr)
 {
-   if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end)
-   return 1;
-   return 0;
+   return addr >= (unsigned long)_stext && addr <= (unsigned long)_end;
 }
 
-void __init setup_arch(char **cmdline_p)
+/* uboot_tag values for U-boot - kernel ABI revisions 0+; see head.S */
+#define UBOOT_REV0P_TAG_NONE   0
+#define UBOOT_REV0P_TAG_CMDLINE1
+#define UBOOT_REV0P_TAG_DTB2
+
+void __init handle_uboot_args(void)
 {
+   bool append_boot_cmdline = false;
+   bool use_embedded_dtb = true;
+
 #ifdef CONFIG_ARC_UBOOT_SUPPORT
+   /* check that we know this tag */
+   if (uboot_tag != UBOOT_REV0P_TAG_NONE &&
+   uboot_tag != UBOOT_REV0P_TAG_CMDLINE &&
+   uboot_tag != UBOOT_REV0P_TAG_DTB)
+   panic("Invalid uboot tag: '%08x'\n", uboot_tag);
+
/* make sure that uboot passed pointer to cmdline/dtb is valid */
-   if (uboot_tag && is_kernel((unsigned long)uboot_arg))
+   if (uboot_tag != UBOOT_REV0P_TAG_NONE && is_kernel((unsigned 
long)uboot_arg))
panic("Invalid uboot arg\n");
 
/* See if u-boot passed an external Device Tree blob */
-   machine_desc = setup_machine_fdt(uboot_arg);/* uboot_tag == 2 */
-   if (!machine_desc)
+   if (uboot_tag == UBOOT_REV0P_TAG_DTB) {
+   machine_desc = setup_machine_fdt(uboot_arg);
+
+   /* external Device Tree blob is invalid - use embedded one */
+   use_embedded_dtb = !machine_desc;
+   }
+
+   if (uboot_tag == UBOOT_REV0P_TAG_CMDLINE)
+   append_boot_cmdline = true;
 #endif
-   {
-   /* No, so try the embedded one */
+
+   if (use_embedded_dtb) {
machine_desc = setup_machine_fdt(__dtb_start);
if (!machine_desc)
panic("Embedded DT invalid\n");
+   }
 
-   /*
-* If we are here, it is established that @uboot_arg didn't
-* point to DT blob. Instead if u-boot says it is cmdline,
-* append to embedded DT cmdline.
-* setup_machine_fdt() would have populated @boot_command_line
-*/
-   if (uboot_tag == 1) {
-   /* Ensure a whitespace between the 2 cmdlines */
-   strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
-   strlcat(boot_command_line, uboot_arg,
-   COMMAND_LINE_SIZE);
-   }
+   /*
+* If we are here, U-boot says that @uboot_arg is cmdline, so append it
+* to embedded DT cmdline.
+*/
+   if (append_boot_cmdline) {
+   /* Ensure a whitespace between the 2 cmdlines */
+   strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
+   strlcat(boot_command_line, uboot_arg, COMMAND_LINE_SIZE);
}
+}
+
+void __init setup_arch(char **cmdline_p)
+{
+   handle_uboot_args();
 
/* Save unparsed command line copy for /proc/cmdline */
*cmdline_p = boot_command_line;
-- 
2.14.5


___
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc


[PATCH] don't check console device file on fs when booting with initrd/initramfs

2019-02-06 Thread Alexey Brodkin
In case of initrd/initramfs /dev/console might not exist that early
as devtmpfs is mounted a bit later by /init process so disable this
check in that case.

Signed-off-by: Alexey Brodkin 
---
 init/main.c | 10 +-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/init/main.c b/init/main.c
index 387a2d7dc90b..5b904bc78fa4 100644
--- a/init/main.c
+++ b/init/main.c
@@ -1112,7 +1112,9 @@ static int __ref kernel_init(void *unused)
 
 static noinline void __init kernel_init_freeable(void)
 {
+#ifndef CONFIG_BLK_DEV_INITRD
struct kstat console_stat;
+#endif
/*
 * Wait until kthreadd is all set-up.
 */
@@ -1144,11 +1146,17 @@ static noinline void __init kernel_init_freeable(void)
 
do_basic_setup();
 
-   /* Use /dev/console to infer if the rootfs is setup properly */
+#ifndef CONFIG_BLK_DEV_INITRD
+   /*
+* Use /dev/console to infer if the rootfs is setup properly.
+* In case of initrd or initramfs /dev/console might be instantiated
+* later by /init so don't do this check for CONFIG_BLK_DEV_INITRD
+*/
if (vfs_lstat((char __user *) "/dev/console", (struct kstat __user *) 
&console_stat)
|| !S_ISCHR(console_stat.mode)) {
panic("/dev/console is missing or not a character 
device!\nPlease ensure your rootfs is properly configured\n");
}
+#endif
 
/* Open the /dev/console on the rootfs, this should never fail */
if (ksys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
-- 
2.16.2


___
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc