[U-Boot-Users] [Patch 05/17] U-Boot-V2:ARM: Introduce capability to have different stack/malloc area
The default setup of ARM memory allocation is as follows: ---- Stack Area ---- Heap Area --- _u_boot_start Rest of U-Boot..
This is an excellent strategy to catch stack overflow and memory buffer overflow issues. However, in conditions where: a) U-Boot is automatically loaded by h/w in the default location without a writable memory area above it, this will crash, b) Multiple non-contiguous memory areas available in system (e.g. SRAM and SDRAM), but the area where U-Boot is loaded is restricted in size and cannot fit the required heap and stack areas. In these cases, we need to have ability to move the Heap and stack to the area of our choice. This patch introduces CONFIG_MALLOC_START for machine configurations which require this. This would need to be enabled only if MACH_CAN_MODIFY_MALLOC_START is defined by the machine configurations that desire it. I have clubbed both heap and stack area to still catch some of those overflow issues.
Signed-off-by: Nishanth Menonx0nishan@ti.com
--- arch/arm/Kconfig | 22 ++++++++++++++++++++++ arch/arm/cpu/start-arm.S | 9 +++++++++ arch/arm/lib/arm.c | 5 +++++ 3 files changed, 36 insertions(+)
Index: u-boot-v2.git/arch/arm/lib/arm.c =================================================================== --- u-boot-v2.git.orig/arch/arm/lib/arm.c 2008-05-20 17:19:42.000000000 -0500 +++ u-boot-v2.git/arch/arm/lib/arm.c 2008-05-20 17:26:33.000000000 -0500 @@ -6,8 +6,13 @@
int arm_mem_malloc_init(void) { +#ifndef CONFIG_MALLOC_START mem_malloc_init((void *)(_u_boot_start - CFG_MALLOC_LEN), (void *)_u_boot_start); +#else + mem_malloc_init((void *)(CONFIG_MALLOC_START - CFG_MALLOC_LEN), + (void *)CONFIG_MALLOC_START); +#endif return 0; }
Index: u-boot-v2.git/arch/arm/Kconfig =================================================================== --- u-boot-v2.git.orig/arch/arm/Kconfig 2008-05-20 17:19:42.000000000 -0500 +++ u-boot-v2.git/arch/arm/Kconfig 2008-05-20 17:26:33.000000000 -0500 @@ -168,6 +168,28 @@ If you want to start a 2.6 kernel and use an initrd image say y here.
+config MACH_CAN_MODIFY_MALLOC_START + bool + +config MALLOC_START_MODIFY + bool "Change Malloc Address location from default" + default n + depends on MACH_CAN_MODIFY_MALLOC_START + help + Say Y here if you meanto put malloc and stack elsewhere. + The default is to put Malloc and stack just above the + interrupt vectors(_start). It is usually desired to keep it here + as we can catch stack overflow and corruption issues easily. + USE THIS OPTION WITH CAUTION + +config MALLOC_START + hex + prompt "Provide Alternate Malloc Start address" + depends on MALLOC_START_MODIFY + help + Provide the alternate malloc start address. Remember that the area + that will be used will be (this address) to (this address - CFG_MALLOC_LEN - CONFIG_STACKSIZE) + endmenu
source common/Kconfig Index: u-boot-v2.git/arch/arm/cpu/start-arm.S =================================================================== --- u-boot-v2.git.orig/arch/arm/cpu/start-arm.S 2008-05-20 17:26:30.000000000 -0500 +++ u-boot-v2.git/arch/arm/cpu/start-arm.S 2008-05-20 17:26:33.000000000 -0500 @@ -90,11 +90,20 @@ * FIXME *************************************************************************/
+#ifndef CONFIG_MALLOC_START _MALLOC_START: .word _start - CFG_MALLOC_LEN
_STACK_START: .word _start - CFG_MALLOC_LEN - CONFIG_STACKSIZE +#else +_MALLOC_START: + .word CONFIG_MALLOC_START - CFG_MALLOC_LEN + +_STACK_START: + .word CONFIG_MALLOC_START - CFG_MALLOC_LEN - CONFIG_STACKSIZE +#endif +
/* * These are defined in the board-specific linker script.
On Wed, May 21, 2008 at 11:26:25AM -0500, Menon, Nishanth wrote:
The default setup of ARM memory allocation is as follows:
Stack Area
Heap Area
_u_boot_start Rest of U-Boot..
This is an excellent strategy to catch stack overflow and memory buffer overflow issues. However, in conditions where: a) U-Boot is automatically loaded by h/w in the default location without a writable memory area above it, this will crash, b) Multiple non-contiguous memory areas available in system (e.g. SRAM and SDRAM), but the area where U-Boot is loaded is restricted in size and cannot fit the required heap and stack areas. In these cases, we need to have ability to move the Heap and stack to the area of our choice. This patch introduces CONFIG_MALLOC_START for machine configurations which require this. This would need to be enabled only if MACH_CAN_MODIFY_MALLOC_START is defined by the machine configurations that desire it. I have clubbed both heap and stack area to still catch some of those overflow issues.
This patch rises an issue we currently have in U-Boot-v2: We have as many stack/memory strategies as we have architectures :(
Instead of modifying this for one architecture I would prefer something like this (currently no implementation, only kconfig). Would this solve your issues?
regards, Sascha
diff --git a/common/Kconfig b/common/Kconfig index 79a3684..d764482 100644 --- a/common/Kconfig +++ b/common/Kconfig @@ -19,13 +19,66 @@ menu "General Settings " config BOARDINFO string
+menu "memory layout " + config TEXT_BASE + depends on HAVE_CONFIGURABLE_TEXT_BASE prompt "TEXT_BASE" hex default ARCH_TEXT_BASE help The Address U-Boot gets linked at.
+choice + prompt "select stack base policy" + depends on HAVE_CONFIGURABLE_STACK + default STACK_BASE_FIXED + +config STACK_BASE_DEFAULT + bool "place stack before malloc space" + +config STACK_BASE_FIXED + bool "manually assign a stack base" + +endchoice + +config STACK_BASE + depends on STACK_BASE_FIXED + hex + prompt "STACK_BASE" + +config STACK_SIZE + hex + depends on HAVE_CONFIGURABLE_STACK + default 0x8000 + prompt "Stack size" + +choice + prompt "select stack base policy" + depends on HAVE_CONFIGURABLE_MALLOC + +config MALLOC_BASE_DEFAULT + bool + prompt "place stack before U-Boot" + +config MALLOC_BASE_FIXED + bool + prompt "manually assign a malloc base" + +endchoice + +config MALLOC_BASE + depends on MALLOC_BASE_FIXED + hex + prompt "MALLOC_BASE" + +config MALLOC_SIZE + hex + depends on HAVE_CONFIGURABLE_MALLOC + default 0x400000 + prompt "malloc area size" +endmenu + config BROKEN bool prompt "Prompt for broken or incomplete code"
Sascha,
-----Original Message----- From: Sascha Hauer [mailto:s.hauer@pengutronix.de] Sent: Tuesday, June 03, 2008 3:08 AM To: Menon, Nishanth Cc: u-boot-users@lists.sourceforge.net; Laurent Desnogues; dirk.behme@googlemail.com; philip.balister@gmail.com; Gopinath, Thara; Kamat, Nishant; Syed Mohammed, Khasim Subject: Re: [Patch 05/17] U-Boot-V2:ARM: Introduce capability to havedifferent stack/malloc area
This patch rises an issue we currently have in U-Boot-v2: We have as many stack/memory strategies as we have architectures :(
Instead of modifying this for one architecture I would prefer something like this (currently no implementation, only kconfig). Would this solve your issues?
Yes, :). Couple of minor comments though..
diff --git a/common/Kconfig b/common/Kconfig index 79a3684..d764482 100644 --- a/common/Kconfig +++ b/common/Kconfig @@ -19,13 +19,66 @@ menu "General Settings " config BOARDINFO string
+menu "memory layout "
Curious: Why have the extra space? I see this in other places too.. it kind of messes up the defconfig with trailing spaces :(.
+choice
- prompt "select stack base policy"
s/stack/heap?
- depends on HAVE_CONFIGURABLE_MALLOC
+config MALLOC_BASE_DEFAULT
- bool
- prompt "place stack before U-Boot"
s/stack/heap?
+config MALLOC_BASE_FIXED
- bool
- prompt "manually assign a malloc base"
+endchoice
+endmenu
Ack to the changes. This should be good for me.
Regards, Nishanth Menon
On Tue, Jun 03, 2008 at 10:04:29AM -0500, Menon, Nishanth wrote:
Sascha,
-----Original Message----- From: Sascha Hauer [mailto:s.hauer@pengutronix.de] Sent: Tuesday, June 03, 2008 3:08 AM To: Menon, Nishanth Cc: u-boot-users@lists.sourceforge.net; Laurent Desnogues; dirk.behme@googlemail.com; philip.balister@gmail.com; Gopinath, Thara; Kamat, Nishant; Syed Mohammed, Khasim Subject: Re: [Patch 05/17] U-Boot-V2:ARM: Introduce capability to havedifferent stack/malloc area
This patch rises an issue we currently have in U-Boot-v2: We have as many stack/memory strategies as we have architectures :(
Instead of modifying this for one architecture I would prefer something like this (currently no implementation, only kconfig). Would this solve your issues?
Yes, :). Couple of minor comments though..
diff --git a/common/Kconfig b/common/Kconfig index 79a3684..d764482 100644 --- a/common/Kconfig +++ b/common/Kconfig @@ -19,13 +19,66 @@ menu "General Settings " config BOARDINFO string
+menu "memory layout "
Curious: Why have the extra space? I see this in other places too.. it kind of messes up the defconfig with trailing spaces :(.
It's just to align the menu arrows nicely under each other in make menuconfig.
+choice
- prompt "select stack base policy"
s/stack/heap?
- depends on HAVE_CONFIGURABLE_MALLOC
+config MALLOC_BASE_DEFAULT
- bool
- prompt "place stack before U-Boot"
s/stack/heap?
No, this is the processor stack...
+config MALLOC_BASE_FIXED
- bool
- prompt "manually assign a malloc base"
...while this is the malloc heap.
+endchoice
+endmenu
Ack to the changes. This should be good for me.
Regards, Nishanth Menon
Sascha,
-----Original Message----- From: Sascha Hauer [mailto:s.hauer@pengutronix.de] Sent: Tuesday, June 03, 2008 10:24 AM To: Menon, Nishanth Cc: u-boot-users@lists.sourceforge.net; Laurent Desnogues; dirk.behme@googlemail.com; philip.balister@gmail.com; Gopinath, Thara; Kamat, Nishant; Syed Mohammed, Khasim Subject: Re: [Patch 05/17] U-Boot-V2:ARM: Introduce capability tohavedifferent stack/malloc area
Instead of modifying this for one architecture I would prefer something like this (currently no implementation, only kconfig). Would this solve your issues?
Modification only done for ARM.
Signed-off-by: Nishanth Menonx0nishan@ti.com
--- arch/arm/cpu/start-arm.S | 27 +++++++++++++++++++- arch/arm/lib/arm.c | 16 ++++++++++-- common/Kconfig | 61 +++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 100 insertions(+), 4 deletions(-)
Index: u-boot.v2/arch/arm/lib/arm.c =================================================================== --- u-boot.v2.orig/arch/arm/lib/arm.c 2008-06-03 20:56:27.000000000 -0500 +++ u-boot.v2/arch/arm/lib/arm.c 2008-06-03 20:56:46.000000000 -0500 @@ -4,10 +4,22 @@ #include <asm/u-boot-arm.h> #include <reloc.h>
+#ifdef CONFIG_MALLOC_BASE +#define ARM_MALLOC_START CONFIG_MALLOC_BASE +#else +#define ARM_MALLOC_START _u_boot_start +#endif + +#ifdef CONFIG_MALLOC_SIZE +#define ARM_MALLOC_SIZE CONFIG_MALLOC_SIZE +#else +#define ARM_MALLOC_SIZE CFG_MALLOC_LEN +#endif + int arm_mem_malloc_init(void) { - mem_malloc_init((void *)(_u_boot_start - CFG_MALLOC_LEN), - (void *)_u_boot_start); + mem_malloc_init((void *)(ARM_MALLOC_START - ARM_MALLOC_SIZE), + (void *)ARM_MALLOC_START); return 0; }
Index: u-boot.v2/arch/arm/cpu/start-arm.S =================================================================== --- u-boot.v2.orig/arch/arm/cpu/start-arm.S 2008-06-03 20:56:40.000000000 -0500 +++ u-boot.v2/arch/arm/cpu/start-arm.S 2008-06-03 21:08:04.000000000 -0500 @@ -90,11 +90,34 @@ * FIXME *************************************************************************/
+#ifdef CONFIG_MALLOC_BASE +#define ARM_MALLOC_START CONFIG_MALLOC_BASE +#else +#define ARM_MALLOC_START _start +#endif + +#ifdef CONFIG_MALLOC_SIZE +#define ARM_MALLOC_SIZE CONFIG_MALLOC_SIZE +#else +#define ARM_MALLOC_SIZE CFG_MALLOC_LEN +#endif _MALLOC_START: - .word _start - CFG_MALLOC_LEN + .word ARM_MALLOC_START - ARM_MALLOC_SIZE
+#ifdef CONFIG_STACK_BASE +#define ARM_STACK_START CONFIG_STACK_BASE +#else +#define ARM_STACK_START (ARM_MALLOC_START - ARM_MALLOC_SIZE) +#endif + +#ifdef CONFIG_STACK_SIZE +#define ARM_STACK_SIZE CONFIG_STACK_SIZE +#else +#define ARM_STACK_SIZE CFG_STACK_LEN +#endif _STACK_START: - .word _start - CFG_MALLOC_LEN - CONFIG_STACKSIZE + .word ARM_STACK_START - CONFIG_STACKSIZE +
/* * These are defined in the board-specific linker script. Index: u-boot.v2/common/Kconfig =================================================================== --- u-boot.v2.orig/common/Kconfig 2008-06-03 20:56:40.000000000 -0500 +++ u-boot.v2/common/Kconfig 2008-06-03 21:08:37.000000000 -0500 @@ -19,13 +19,74 @@ config BOARDINFO string
+menu "memory layout " + +config HAVE_CONFIGURABLE_TEXT_BASE + bool + config TEXT_BASE + depends on HAVE_CONFIGURABLE_TEXT_BASE prompt "TEXT_BASE" hex default ARCH_TEXT_BASE help The Address U-Boot gets linked at.
+config HAVE_CONFIGURABLE_STACK + bool +choice + prompt "select stack base policy" + depends on HAVE_CONFIGURABLE_STACK + default STACK_BASE_FIXED + +config STACK_BASE_DEFAULT + bool "place stack before malloc space" + +config STACK_BASE_FIXED + bool "manually assign a stack base" + +endchoice + +config STACK_BASE + depends on STACK_BASE_FIXED + hex + prompt "STACK_BASE" + +config STACK_SIZE + hex + depends on HAVE_CONFIGURABLE_STACK + default 0x8000 + prompt "Stack size" + +config HAVE_CONFIGURABLE_MALLOC + bool + +choice + prompt "select malloc base policy" + depends on HAVE_CONFIGURABLE_MALLOC + +config MALLOC_BASE_DEFAULT + bool + prompt "place malloc before U-Boot" + +config MALLOC_BASE_FIXED + bool + prompt "manually assign a malloc base" + +endchoice + +config MALLOC_BASE + depends on MALLOC_BASE_FIXED + hex + prompt "MALLOC_BASE" + +config MALLOC_SIZE + hex + depends on HAVE_CONFIGURABLE_MALLOC + default 0x400000 + prompt "malloc area size" +endmenu + config BROKEN bool prompt "Prompt for broken or incomplete code"
On Wed, Jun 04, 2008 at 12:04:51AM -0500, Menon, Nishanth wrote:
Sascha,
-----Original Message----- From: Sascha Hauer [mailto:s.hauer@pengutronix.de] Sent: Tuesday, June 03, 2008 10:24 AM To: Menon, Nishanth Cc: u-boot-users@lists.sourceforge.net; Laurent Desnogues; dirk.behme@googlemail.com; philip.balister@gmail.com; Gopinath, Thara; Kamat, Nishant; Syed Mohammed, Khasim Subject: Re: [Patch 05/17] U-Boot-V2:ARM: Introduce capability tohavedifferent stack/malloc area
Instead of modifying this for one architecture I would prefer something like this (currently no implementation, only kconfig). Would this solve your issues?
Modification only done for ARM.
I checked in a similar version of the patch, should work for you.
Sascha
participants (2)
-
Menon, Nishanth -
Sascha Hauer