1 files changed, 77 insertions, 0 deletions

diff --git a/meta/recipes-kernel/linux/linux-omap-2.6.29/no-cortex-deadlock.patch b/meta/recipes-kernel/linux/linux-omap-2.6.29/no-cortex-deadlock.patch
new file mode 100644
index 0000000000..78547c8969
--- /dev/null
+++ b/meta/recipes-kernel/linux/linux-omap-2.6.29/no-cortex-deadlock.patch
@@ -0,0 +1,77 @@
+From: Mans Rullgard <mans@mansr.com>
+Date: Sat, 16 Aug 2008 23:03:06 +0000 (+0100)
+Subject: ARM: Workaround for erratum 451034
+X-Git-Url: http://git.mansr.com/?p=linux-omap;a=commitdiff_plain;h=b84fa87873ffb68ad23930cf6cddeea8bec43ede
+
+ARM: Workaround for erratum 451034
+
+On Cortex-A8 r1p0 and r1p1, executing a NEON store with an integer
+store in the store buffer, can cause a processor deadlock under
+certain conditions.
+
+Executing a DMB instruction before saving NEON/VFP registers and before
+return to userspace makes it safe to run code which includes similar
+counter-measures.  Userspace code can still trigger the deadlock, so
+a different workaround is required to safely run untrusted code.
+
+See ARM Cortex-A8 Errata Notice (PR120-PRDC-008070) for full details.
+
+Signed-off-by: Mans Rullgard <mans@mansr.com>
+---
+
+diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
+index aa475d9..41d536e 100644
+--- a/arch/arm/Kconfig
++++ b/arch/arm/Kconfig
+@@ -1117,6 +1117,22 @@ config NEON
+          Say Y to include support code for NEON, the ARMv7 Advanced SIMD
+          Extension.
+ 
++config ARM_ERRATUM_451034
++       bool "Enable workaround for ARM erratum 451034"
++       depends on VFPv3
++       help
++         On Cortex-A8 r1p0 and r1p1, executing a NEON store with an integer
++         store in the store buffer, can cause a processor deadlock under
++         certain conditions.
++
++         See ARM Cortex-A8 Errata Notice (PR120-PRDC-008070) for full details.
++
++         Say Y to include a partial workaround.
++
++         WARNING: Even with this option enabled, userspace code can trigger
++         the deadlock.  To safely run untrusted code, a different fix is
++         required.
++
+ endmenu
+ 
+ menu "Userspace binary formats"
+diff --git a/arch/arm/include/asm/vfpmacros.h b/arch/arm/include/asm/vfpmacros.h
+index 422f3cc..934798b 100644
+--- a/arch/arm/include/asm/vfpmacros.h
++++ b/arch/arm/include/asm/vfpmacros.h
+@@ -32,6 +32,9 @@
+ 
+        @ write all the working registers out of the VFP
+        .macro  VFPFSTMIA, base, tmp
++#ifdef CONFIG_ARM_ERRATUM_451034
++       dmb
++#endif
+ #if __LINUX_ARM_ARCH__ < 6
+        STC     p11, cr0, [\base],#33*4             @ FSTMIAX \base!, {d0-d15}
+ #else
+diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
+index 060d7e2..9799a35 100644
+--- a/arch/arm/kernel/entry-common.S
++++ b/arch/arm/kernel/entry-common.S
+@@ -69,6 +69,10 @@ no_work_pending:
+        /* perform architecture specific actions before user return */
+        arch_ret_to_user r1, lr
+ 
++#ifdef CONFIG_ARM_ERRATUM_451034
++       dmb
++#endif
++
+        @ slow_restore_user_regs
+        ldr     r1, [sp, #S_PSR]                @ get calling cpsr
+        ldr     lr, [sp, #S_PC]!                @ get pc