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authorMark Brown <broonie@opensource.wolfsonmicro.com>2010-08-16 18:42:58 +0100
committerMark Brown <broonie@opensource.wolfsonmicro.com>2010-08-16 18:42:58 +0100
commite4862f2f6f5653dfb67f3ba2b6f0bc74516ed51a (patch)
tree1db5a0540a4eecfad9b7daee476b985e82ddc810 /arch/arm/include/asm/stackprotector.h
parentec62dbd7eb8e3dddb221da89ecbcea0fc3dee8c1 (diff)
parentb2c1e07b81a126e5846dfc3d36f559d861df59f4 (diff)
Merge branch 'for-2.6.36' into for-2.6.37
Fairly simple conflicts, the most serious ones are the i.MX ones which I suspect now need another rename. Conflicts: arch/arm/mach-mx2/clock_imx27.c arch/arm/mach-mx2/devices.c arch/arm/mach-omap2/board-rx51-peripherals.c arch/arm/mach-omap2/board-zoom2.c sound/soc/fsl/mpc5200_dma.c sound/soc/fsl/mpc5200_dma.h sound/soc/fsl/mpc8610_hpcd.c sound/soc/pxa/spitz.c
Diffstat (limited to 'arch/arm/include/asm/stackprotector.h')
-rw-r--r--arch/arm/include/asm/stackprotector.h38
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/arm/include/asm/stackprotector.h b/arch/arm/include/asm/stackprotector.h
new file mode 100644
index 00000000000..de003327be9
--- /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 <linux/random.h>
+#include <linux/version.h>
+
+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 */