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| author |  Al Viro <viro@ZenIV.linux.org.uk>
| 2018-08-11 01:04:55 +0100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk>
| 2018-08-16 21:02:17 -0400 |
| commit | 060581c158a66fcc68f8877ccd0d60fd9aeca65e (patch) | |
| tree | 93b2c4f9b849dbf6a3f0751569154755307019ce /arch/alpha/kernel/entry.S | |
| parent | Merge tag 'for-linus-4.19-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/... (diff) | |
| download | linux-060581c158a66fcc68f8877ccd0d60fd9aeca65e.tar.gz linux-060581c158a66fcc68f8877ccd0d60fd9aeca65e.tar.bz2 linux-060581c158a66fcc68f8877ccd0d60fd9aeca65e.zip | |
alpha: use alpha_ni_syscall only for syscall zero
Once upon a time it used to have a C part that printed a warning
about unimplemented OSF syscalls. That's what it's been doing
all over the OSF syscall range, while the native Linux syscall
range uses sys_ni_syscall().
With those warnings about unimplemented OSF syscalls gone (circa 2.4),
alpha_ni_syscall() has shrunk to that little bit of asm and the
only reason it hasn't been replaced with sys_ni_syscall() everywhere
is that extra twist needed in case of syscall #0.
Let's keep it only for syscall #0 and replace the rest with sys_ni_syscall.
And use sys_ni_syscall for "number out range" in ptraced-call case, as
we'd been doing for normal codepath since 2.1.86...
Acked-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch/alpha/kernel/entry.S')
| -rw-r--r-- | arch/alpha/kernel/entry.S | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S index c64806a2daf5..21840e7042f3 100644 --- a/arch/alpha/kernel/entry.S +++ b/arch/alpha/kernel/entry.S @@ -473,7 +473,7 @@ entSys: bne $3, strace beq $4, 1f ldq $27, 0($5) -1: jsr $26, ($27), alpha_ni_syscall +1: jsr $26, ($27), sys_ni_syscall ldgp $gp, 0($26) blt $0, $syscall_error /* the call failed */ stq $0, 0($sp) @@ -587,7 +587,7 @@ strace: /* get the system call pointer.. */ lda $1, NR_SYSCALLS($31) lda $2, sys_call_table - lda $27, alpha_ni_syscall + lda $27, sys_ni_syscall cmpult $0, $1, $1 s8addq $0, $2, $2 beq $1, 1f @@ -843,15 +843,20 @@ sys_rt_sigreturn: .end sys_rt_sigreturn .align 4 - .globl alpha_ni_syscall - .ent alpha_ni_syscall -alpha_ni_syscall: + .globl alpha_syscall_zero + .ent alpha_syscall_zero +alpha_syscall_zero: .prologue 0 - /* Special because it also implements overflow handling via - syscall number 0. And if you recall, zero is a special - trigger for "not an error". Store large non-zero there. */ + /* Special because it needs to do something opposite to + force_successful_syscall_return(). We use the saved + syscall number for that, zero meaning "not an error". + That works nicely, but for real syscall 0 we need to + make sure that this logics doesn't get confused. + Store a non-zero there - -ENOSYS we need in register + for our return value will do just fine. + */ lda $0, -ENOSYS unop stq $0, 0($sp) ret -.end alpha_ni_syscall +.end alpha_syscall_zero |