From 990cb8acf23cab19a2930f1ed5e7dc108f89079b Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Mon, 14 Jun 2010 16:27:19 -0400 Subject: [ARM] implement arch_randomize_brk() For this feature to take effect, CONFIG_COMPAT_BRK must be turned off. This can safely be turned off for any EABI user space versions. Signed-off-by: Nicolas Pitre --- arch/arm/include/asm/elf.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h index 51662feb9f1d..0a96e8c1b82a 100644 --- a/arch/arm/include/asm/elf.h +++ b/arch/arm/include/asm/elf.h @@ -121,4 +121,7 @@ int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs); extern void elf_set_personality(const struct elf32_hdr *); #define SET_PERSONALITY(ex) elf_set_personality(&(ex)) +extern unsigned long arch_randomize_brk(struct mm_struct *mm); +#define arch_randomize_brk arch_randomize_brk + #endif -- cgit v1.2.3 From c743f38013aeff58ef6252601e397b5ba281c633 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Mon, 24 May 2010 23:55:42 -0400 Subject: ARM: initial stack protector (-fstack-protector) support This is the very basic stuff without the changing canary upon task switch yet. Just the Kconfig option and a constant canary value initialized at boot time. Signed-off-by: Nicolas Pitre --- arch/arm/Kconfig | 12 +++++++++++ arch/arm/Makefile | 4 ++++ arch/arm/include/asm/stackprotector.h | 38 +++++++++++++++++++++++++++++++++++ arch/arm/kernel/process.c | 6 ++++++ 4 files changed, 60 insertions(+) create mode 100644 arch/arm/include/asm/stackprotector.h (limited to 'arch/arm/include') diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 1f254bd6c937..f160b93691cd 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1374,6 +1374,18 @@ config UACCESS_WITH_MEMCPY However, if the CPU data cache is using a write-allocate mode, this option is unlikely to provide any performance gain. +config CC_STACKPROTECTOR + bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)" + help + This option turns on the -fstack-protector GCC feature. This + feature puts, at the beginning of functions, a canary value on + the stack just before the return address, and validates + the value just before actually returning. Stack based buffer + overflows (that need to overwrite this return address) now also + overwrite the canary, which gets detected and the attack is then + neutralized via a kernel panic. + This feature requires gcc version 4.2 or above. + endmenu menu "Boot options" diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 64ba313724d2..ddf6da158ad8 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -34,6 +34,10 @@ ifeq ($(CONFIG_FRAME_POINTER),y) KBUILD_CFLAGS +=-fno-omit-frame-pointer -mapcs -mno-sched-prolog endif +ifeq ($(CONFIG_CC_STACKPROTECTOR),y) +KBUILD_CFLAGS +=-fstack-protector +endif + ifeq ($(CONFIG_CPU_BIG_ENDIAN),y) KBUILD_CPPFLAGS += -mbig-endian AS += -EB diff --git a/arch/arm/include/asm/stackprotector.h b/arch/arm/include/asm/stackprotector.h new file mode 100644 index 000000000000..de003327be97 --- /dev/null +++ b/arch/arm/include/asm/stackprotector.h @@ -0,0 +1,38 @@ +/* + * GCC stack protector support. + * + * Stack protector works by putting predefined pattern at the start of + * the stack frame and verifying that it hasn't been overwritten when + * returning from the function. The pattern is called stack canary + * and gcc expects it to be defined by a global variable called + * "__stack_chk_guard" on ARM. This unfortunately means that on SMP + * we cannot have a different canary value per task. + */ + +#ifndef _ASM_STACKPROTECTOR_H +#define _ASM_STACKPROTECTOR_H 1 + +#include +#include + +extern unsigned long __stack_chk_guard; + +/* + * Initialize the stackprotector canary value. + * + * NOTE: this must only be called from functions that never return, + * and it must always be inlined. + */ +static __always_inline void boot_init_stack_canary(void) +{ + unsigned long canary; + + /* Try to get a semi random initial value. */ + get_random_bytes(&canary, sizeof(canary)); + canary ^= LINUX_VERSION_CODE; + + current->stack_canary = canary; + __stack_chk_guard = current->stack_canary; +} + +#endif /* _ASM_STACKPROTECTOR_H */ diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 1c6eb7ed9642..090ac9459da1 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -37,6 +37,12 @@ #include #include +#ifdef CONFIG_CC_STACKPROTECTOR +#include +unsigned long __stack_chk_guard __read_mostly; +EXPORT_SYMBOL(__stack_chk_guard); +#endif + static const char *processor_modes[] = { "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" , "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26", -- cgit v1.2.3 From 35fe2fc44ac4202261317ccce2ef69991bc01c57 Mon Sep 17 00:00:00 2001 From: Saeed Bishara Date: Thu, 3 Jun 2010 14:58:46 +0300 Subject: [ARM] PCI: add platform private data to pci_sys_data Add private_data pointer to the pci_sys_data, this pointer can be used for holding platform specific data for each pci controller. Signed-off-by: Saeed Bishara Signed-off-by: Nicolas Pitre --- arch/arm/include/asm/mach/pci.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/mach/pci.h b/arch/arm/include/asm/mach/pci.h index 52f0da1e97df..16330bd0657c 100644 --- a/arch/arm/include/asm/mach/pci.h +++ b/arch/arm/include/asm/mach/pci.h @@ -46,6 +46,7 @@ struct pci_sys_data { /* IRQ mapping */ int (*map_irq)(struct pci_dev *, u8, u8); struct hw_pci *hw; + void *private_data; /* platform controller private data */ }; /* -- cgit v1.2.3 From 392c57a2ec811db37ae45adc513704cf92ba3e69 Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 26 Jul 2010 11:02:31 +0100 Subject: ARM: fix build warning in asm/elf.h CC kernel/elfcore.o In file included from include/linux/elf.h:7, from kernel/elfcore.c:1: arch/arm/include/asm/elf.h:124: warning: 'struct mm_struct' declared inside parameter list arch/arm/include/asm/elf.h:124: warning: its scope is only this definition or declaration, which is probably not what you want Signed-off-by: Russell King --- arch/arm/include/asm/elf.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/elf.h b/arch/arm/include/asm/elf.h index 0a96e8c1b82a..6750b8e45a49 100644 --- a/arch/arm/include/asm/elf.h +++ b/arch/arm/include/asm/elf.h @@ -121,6 +121,7 @@ int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs); extern void elf_set_personality(const struct elf32_hdr *); #define SET_PERSONALITY(ex) elf_set_personality(&(ex)) +struct mm_struct; extern unsigned long arch_randomize_brk(struct mm_struct *mm); #define arch_randomize_brk arch_randomize_brk -- cgit v1.2.3