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authorSuzuki K. Poulose <suzuki.poulose@arm.com>2015-01-21 15:43:11 +0300
committerCatalin Marinas <catalin.marinas@arm.com>2015-01-23 20:11:44 +0300
commit2d888f48e056119495847a269a435d5c3d9df349 (patch)
treed63ed442721b6ce1305b46105982554d340a0702 /arch/arm64/include/asm/ptrace.h
parent736d474f0fafd1486f178570bc47660ee9dfdef8 (diff)
downloadlinux-2d888f48e056119495847a269a435d5c3d9df349.tar.xz
arm64: Emulate SETEND for AArch32 tasks
Emulate deprecated 'setend' instruction for AArch32 bit tasks. setend [le/be] - Sets the endianness of EL0 On systems with CPUs which support mixed endian at EL0, the hardware support for the instruction can be enabled by setting the SCTLR_EL1.SED bit. Like the other emulated instructions it is controlled by an entry in /proc/sys/abi/. For more information see : Documentation/arm64/legacy_instructions.txt The instruction is emulated by setting/clearing the SPSR_EL1.E bit, which will be reflected in the PSTATE.E in AArch32 context. This patch also restores the native endianness for the execution of signal handlers, since the process could have changed the endianness. Note: All CPUs on the system must have mixed endian support at EL0. Once the handler is registered, hotplugging a CPU which doesn't support mixed endian, could lead to unexpected results/behavior in applications. Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Punit Agrawal <punit.agrawal@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/ptrace.h')
-rw-r--r--arch/arm64/include/asm/ptrace.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h
index 41ed9e13795e..d6dd9fdbc3be 100644
--- a/arch/arm64/include/asm/ptrace.h
+++ b/arch/arm64/include/asm/ptrace.h
@@ -58,6 +58,13 @@
#define COMPAT_PSR_Z_BIT 0x40000000
#define COMPAT_PSR_N_BIT 0x80000000
#define COMPAT_PSR_IT_MASK 0x0600fc00 /* If-Then execution state mask */
+
+#ifdef CONFIG_CPU_BIG_ENDIAN
+#define COMPAT_PSR_ENDSTATE COMPAT_PSR_E_BIT
+#else
+#define COMPAT_PSR_ENDSTATE 0
+#endif
+
/*
* These are 'magic' values for PTRACE_PEEKUSR that return info about where a
* process is located in memory.