diff options
| author | Suzuki K. Poulose <suzuki.poulose@arm.com> | 2015-01-21 12:43:11 +0000 |
|---|---|---|
| committer | Daniel Rosenberg <drosen@google.com> | 2015-02-05 15:36:28 -0800 |
| commit | 0afb9de55e1b30039dad90d63e19ec757f94ba1e (patch) | |
| tree | 3a1b885abc3c15e040a41cbd0e657c3ba71bf1ec /arch/arm64/include | |
| parent | 4dffed94fa3b731fa3837ede5705cf15aac402b8 (diff) | |
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>
Change-Id: I5993237889a049a23f6c234daa130d3a740d5525
Diffstat (limited to 'arch/arm64/include')
| -rw-r--r-- | arch/arm64/include/asm/cputype.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/ptrace.h | 7 |
2 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h index fbcca4ff12cf..39636a426c56 100644 --- a/arch/arm64/include/asm/cputype.h +++ b/arch/arm64/include/asm/cputype.h @@ -75,6 +75,7 @@ (((mmfr0) & ID_AA64MMFR0_BIGEND_MASK) >> ID_AA64MMFR0_BIGEND_SHIFT) #define SCTLR_EL1_CP15BEN (0x1 << 5) +#define SCTLR_EL1_SED (0x1 << 8) #ifndef __ASSEMBLY__ diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h index 87d66d7b9d65..6f8aed0addaa 100644 --- a/arch/arm64/include/asm/ptrace.h +++ b/arch/arm64/include/asm/ptrace.h @@ -54,6 +54,13 @@ #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. |