On 12/30/2015 03:00 AM, Mike Frysinger wrote:
> Move the error register documentation into the main table rather than
> listing them in sentences after the fact.
>
> Add sparc error return details.
>
> Add details for alpha/arc/m68k/microblaze/nios2/powerpc/superh/tile/xtensa.
>
> Signed-off-by: Mike Frysinger <vapier@xxxxxxxxxx>
Great stuff! Thanks, Mike. Applied. (But afterward, I tweaked things a
little so the table was not so wide.)
Cheers,
Michael
> ---
> man2/syscall.2 | 77 ++++++++++++++++++++++++++++++++++++++++------------------
> 1 file changed, 53 insertions(+), 24 deletions(-)
>
> diff --git a/man2/syscall.2 b/man2/syscall.2
> index ee87416..d35f1ef 100644
> --- a/man2/syscall.2
> +++ b/man2/syscall.2
> @@ -150,47 +150,67 @@ The first table lists the instruction used to transition to kernel mode,
> so you might have to refer to
> .BR vdso (7)),
> the register used to indicate the system call number,
> -and the register used to return the system call result.
> +the register used to return the system call result,
> +and the register used to signal an error.
> .if t \{\
> .ft CW
> \}
> .TS
> -l l1 l l1 l.
> -arch/ABI instruction syscall # retval Notes
> +l l l l l l.
> +arch/ABI instruction syscall # retval error Notes
> _
> -arm/OABI swi NR - a1 NR is syscall #
> -arm/EABI swi 0x0 r7 r0
> -arm64 svc #0 x8 x0
> -blackfin excpt 0x0 P0 R0
> -i386 int $0x80 eax eax
> -ia64 break 0x100000 r15 r8 See below
> -mips syscall v0 v0 See below
> -parisc ble 0x100(%sr2, %r0) r20 r28
> -s390 svc 0 r1 r2 See below
> -s390x svc 0 r1 r2 See below
> -sparc/32 t 0x10 g1 o0
> -sparc/64 t 0x6d g1 o0
> -x86_64 syscall rax rax See below
> -x32 syscall rax rax See below
> +alpha callsys v0 a0 a3 See below *
> +arc trap0 r8 r0 -
> +arm/OABI swi NR - a1 - NR is syscall #
> +arm/EABI swi 0x0 r7 r0 -
> +arm64 svc #0 x8 x0 -
> +blackfin excpt 0x0 P0 R0 -
> +i386 int $0x80 eax eax -
> +ia64 break 0x100000 r15 r8 r10 See below *
> +m68k trap #0 d0 d0 -
> +microblaze brki r14,8 r12 r3 -
> +mips syscall v0 v0 a3 See below *
> +nios2 trap r2 r2 r7
> +parisc ble 0x100(%sr2, %r0) r20 r28 -
> +powerpc sc r0 r3 r0 See below *
> +s390 svc 0 r1 r2 - See below **
> +s390x svc 0 r1 r2 - See below **
> +superh trap #0x17 r3 r0 - See below ****
> +sparc/32 t 0x10 g1 o0 psr/csr See below *
> +sparc/64 t 0x6d g1 o0 psr/csr See below *
> +tile swint1 R10 R00 R01 See below *
> +x86_64 syscall rax rax - See below ***
> +x32 syscall rax rax - See below ***
> +xtensa syscall a2 a2 -
> .TE
> .PP
> +*
> +On a few architectures,
> +a register is used as a boolean (0 == no error while -1 == error) to signal the
> +system call failed.
> +The actual error value is still contained in the return register.
> +On sparc, the carry bit (csr) in the processor status register (psr) is used
> +instead of a full register.
> +
> +**
> For s390 and s390x, NR (the system call number)
> may be passed directly with "svc NR" if it is less than 256.
>
> +***
> The x32 ABI uses the same instruction as the x86_64 ABI and is used on
> the same processors.
> To differentiate between them, the bit mask
> .I __X32_SYSCALL_BIT
> is bitwise-ORed into the system call number for system calls
> under the x32 ABI.
> +Both syscall tables are available though, so setting the bit is not a hard
> +requirement.
>
> -On a few architectures,
> -a register is used to indicate simple boolean failure of the system call:
> -ia64 uses
> -.I r10
> -for this purpose,
> -and mips uses
> -.IR a3 .
> +****
> +On SuperH, the trap number controls the maximum number of args passed.
> +A trap #0x10 can be used with only 0 arg syscalls,
> +a trap #0x11 can be used with 0 or 1 arg syscalls,
> +and so on up to 0x17 for 7 arg syscalls.
> .if t \{\
> .in
> .ft P
> @@ -204,21 +224,30 @@ The second table shows the registers used to pass the system call arguments.
> l l2 l2 l2 l2 l2 l2 l2 l.
> arch/ABI arg1 arg2 arg3 arg4 arg5 arg6 arg7 Notes
> _
> +alpha a0 a1 a2 a3 a4 a5 -
> +arc r0 r1 r2 r3 r4 r5 -
> arm/OABI a1 a2 a3 a4 v1 v2 v3
> arm/EABI r0 r1 r2 r3 r4 r5 r6
> arm64 x0 x1 x2 x3 x4 x5 -
> blackfin R0 R1 R2 R3 R4 R5 -
> i386 ebx ecx edx esi edi ebp -
> ia64 out0 out1 out2 out3 out4 out5 -
> +m68k d1 d2 d3 d4 d5 a0 -
> +microblaze r5 r6 r7 r8 r9 r10 -
> mips/o32 a0 a1 a2 a3 - - - See below
> mips/n32,64 a0 a1 a2 a3 a4 a5 -
> +nios2 r4 r5 r6 r7 r8 r9 -
> parisc r26 r25 r24 r23 r22 r21 -
> +powerpc r3 r4 r5 r6 r7 r8 r9
> s390 r2 r3 r4 r5 r6 r7 -
> s390x r2 r3 r4 r5 r6 r7 -
> +superh r4 r5 r6 r7 r0 r1 r2
> sparc/32 o0 o1 o2 o3 o4 o5 -
> sparc/64 o0 o1 o2 o3 o4 o5 -
> +tile R00 R01 R02 R03 R04 R05 -
> x86_64 rdi rsi rdx r10 r8 r9 -
> x32 rdi rsi rdx r10 r8 r9 -
> +xtensa a6 a3 a4 a5 a8 a9 -
> .TE
> .PP
> The mips/o32 system call convention passes
>
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
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