switch to using trap number 31 for syscalls on sh

nominally the low bits of the trap number on sh are the number of
syscall arguments, but they have never been used by the kernel, and
some code making syscalls does not even know the number of arguments
and needs to pass an arbitrary high number anyway.

sh3/sh4 traditionally used the trap range 16-31 for syscalls, but part
of this range overlapped with hardware exceptions/interrupts on sh2
hardware, so an incompatible range 32-47 was chosen for sh2.

using trap number 31 everywhere, since it's in the existing sh3/sh4
range and does not conflict with sh2 hardware, is a proposed
unification of the kernel syscall convention that will allow binaries
to be shared between sh2 and sh3/sh4. if this is not accepted into the
kernel, we can refit the sh2 target with runtime selection mechanisms
for the trap number, but doing so would be invasive and would entail
non-trivial overhead.

diff --git a/arch/sh/syscall_arch.h b/arch/sh/syscall_arch.h
index 7ee21a56f6e94a643d29a584a4c8516acc9b1920..f63675a81f15667264b5f9e5988c6ef501b16ff2 100644 (file)
--- a/arch/sh/syscall_arch.h
+++ b/arch/sh/syscall_arch.h
@@ -8,7 +8,7 @@
  */
 #define __asm_syscall(trapno, ...) do {   \
        __asm__ __volatile__ (                \
-               "trapa #" #trapno "\n"            \
+               "trapa #31\n"            \
                "or r0, r0\n"                     \
                "or r0, r0\n"                     \
                "or r0, r0\n"                     \

diff --git a/src/internal/sh/syscall.s b/src/internal/sh/syscall.s
index d00712a9702043ff9db9a5b44cd4b9891d82839a..331918a5aaddd0a673606dbb25c2c300d2a83cc7 100644 (file)
--- a/src/internal/sh/syscall.s
+++ b/src/internal/sh/syscall.s
@@ -13,7 +13,7 @@ __syscall:
        mov.l @r15, r7
        mov.l @(4,r15), r0
        mov.l @(8,r15), r1
-       trapa #22
+       trapa #31
        or r0, r0
        or r0, r0
        or r0, r0

diff --git a/src/process/sh/vfork.s b/src/process/sh/vfork.s
index 30e173173f7fd455ae3f58d23c13b8cc26abd65b..48cc9396fab26767afc4ff3516ab94965b616ade 100644 (file)
--- a/src/process/sh/vfork.s
+++ b/src/process/sh/vfork.s
@@ -7,7 +7,7 @@ vfork:
        mov #95, r3
        add r3, r3
 
-       trapa #16
+       trapa #31
        or    r0, r0
        or    r0, r0
        or    r0, r0

diff --git a/src/signal/sh/restore.s b/src/signal/sh/restore.s
index ab26034b5f7f4306049bf6ed98f51933c6fb3d3a..eaedcdfba8577df3c16ce59cd8569ec90bdfb501 100644 (file)
--- a/src/signal/sh/restore.s
+++ b/src/signal/sh/restore.s
@@ -2,7 +2,7 @@
 .type   __restore, @function
 __restore:
        mov   #119, r3  !__NR_sigreturn
-       trapa #16
+       trapa #31
 
        or    r0, r0
        or    r0, r0
@@ -15,7 +15,7 @@ __restore:
 __restore_rt:
        mov   #100, r3  !__NR_rt_sigreturn
        add   #73, r3
-       trapa #16
+       trapa #31
 
        or    r0, r0
        or    r0, r0

diff --git a/src/thread/sh/__unmapself.s b/src/thread/sh/__unmapself.s
index cad91bf60b32041deb471b80f4ff2f6cd8484f9c..0161d53d425da8b9c44ba2bfd678bf9de71770cc 100644 (file)
--- a/src/thread/sh/__unmapself.s
+++ b/src/thread/sh/__unmapself.s
@@ -3,7 +3,7 @@
 .type   __unmapself_sh_mmu, @function
 __unmapself_sh_mmu:
        mov   #91, r3  ! SYS_munmap
-       trapa #18
+       trapa #31
 
        or    r0, r0
        or    r0, r0
@@ -13,7 +13,7 @@ __unmapself_sh_mmu:
 
        mov   #1, r3   ! SYS_exit
        mov   #0, r4
-       trapa #17
+       trapa #31
 
        or    r0, r0
        or    r0, r0

diff --git a/src/thread/sh/clone.s b/src/thread/sh/clone.s
index d6c9184d40ec01f373bdfc91ebd8e737f095fa62..f8ad8451e86674c3c2bc738f67835cf572f88cff 100644 (file)
--- a/src/thread/sh/clone.s
+++ b/src/thread/sh/clone.s
@@ -17,7 +17,7 @@ __clone:
        mov.l @r15,     r6   ! r6 = ptid
        mov.l @(8,r15), r7   ! r7 = ctid
        mov.l @(4,r15), r0   ! r0 = tls
-       trapa #21
+       trapa #31
 
        or r0, r0
        or r0, r0
@@ -38,7 +38,7 @@ __clone:
 
        mov   #1, r3   ! __NR_exit
        mov   r0, r4
-       trapa #17
+       trapa #31
 
        or   r0, r0
        or   r0, r0

diff --git a/src/thread/sh/syscall_cp.s b/src/thread/sh/syscall_cp.s
index 6b28ddf05a56c41d456b90b3d93cb156bfe7240a..c3caface8f83ce8f49a777ef65921dd52c626c93 100644 (file)
--- a/src/thread/sh/syscall_cp.s
+++ b/src/thread/sh/syscall_cp.s
@@ -31,7 +31,7 @@ L1:   .long __cancel@PLT-(1b-.)
        mov.l @(4,r15), r7
        mov.l @(8,r15), r0
        mov.l @(12,r15), r1
-       trapa #22
+       trapa #31
 
 __cp_end:
        ! work around hardware bug

diff --git a/src/unistd/sh/pipe.s b/src/unistd/sh/pipe.s
index d865ae3afb98876d51368b746ca3217f2b049343..46c4908e7b463bfe5c9888033dc2db8172835d0b 100644 (file)
--- a/src/unistd/sh/pipe.s
+++ b/src/unistd/sh/pipe.s
@@ -2,7 +2,7 @@
 .type   pipe, @function
 pipe:
        mov    #42, r3
-       trapa  #17
+       trapa  #31
 
        ! work around hardware bug
        or     r0, r0