diff options
| author | Michael Ellerman <mpe@ellerman.id.au> | 2015-03-28 21:35:16 +1100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2015-03-28 22:03:40 +1100 |
| commit | 529d235a0e190ded1d21ccc80a73e625ebcad09b (patch) | |
| tree | c807f7526f29b79a7ce0b233daf8a1c3030d8dd0 /arch/powerpc/include/uapi/asm | |
| parent | c03e73740d24fbe990291cd9ac2d6ae0d95b975f (diff) | |
powerpc: Add a proper syscall for switching endianness
We currently have a "special" syscall for switching endianness. This is
syscall number 0x1ebe, which is handled explicitly in the 64-bit syscall
exception entry.
That has a few problems, firstly the syscall number is outside of the
usual range, which confuses various tools. For example strace doesn't
recognise the syscall at all.
Secondly it's handled explicitly as a special case in the syscall
exception entry, which is complicated enough without it.
As a first step toward removing the special syscall, we need to add a
regular syscall that implements the same functionality.
The logic is simple, it simply toggles the MSR_LE bit in the userspace
MSR. This is the same as the special syscall, with the caveat that the
special syscall clobbers fewer registers.
This version clobbers r9-r12, XER, CTR, and CR0-1,5-7.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/include/uapi/asm')
| -rw-r--r-- | arch/powerpc/include/uapi/asm/unistd.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/powerpc/include/uapi/asm/unistd.h b/arch/powerpc/include/uapi/asm/unistd.h index ef5b5b1f3123..e4aa173dae62 100644 --- a/arch/powerpc/include/uapi/asm/unistd.h +++ b/arch/powerpc/include/uapi/asm/unistd.h @@ -385,5 +385,6 @@ #define __NR_memfd_create 360 #define __NR_bpf 361 #define __NR_execveat 362 +#define __NR_switch_endian 363 #endif /* _UAPI_ASM_POWERPC_UNISTD_H_ */ |