Hi David,
I just installed a shiny (old) Sparc64 machine, trying to get LTTng to
run on it (2.6.30 kernel), and noticed this problem when extracting the
buffers: lttd (the daemon) causes faults in __copy_from_user() within
splice().
lttd is compiled as a 32-bits process on my system. The kernel is
64-bits kernel.
I think arch/sparc/kernel/sys32.S has an incorrect splice definition:
SIGN2(sys32_splice, sys_splice, %o0, %o1)
The splice() prototype looks like :
long splice(int fd_in, loff_t *off_in, int fd_out,
loff_t *off_out, size_t len, unsigned int flags);
So I think we should have :
SIGN2(sys32_splice, sys_splice, %o0, %o2)
instead, am I correct ?
BTW, I can't figure out why we have %o5 in :
SIGN2(sys32_sync_file_range, compat_sync_file_range, %o0, %o5)
which takes only 4 arguments:
int sync_file_range(int fd, off64_t offset, off64_t nbytes,
unsigned int flags);
maybe it has something to do with the return value ? Anyway it should
not hurt if it is unused.
I provide the patch for splice() below.
With this patch applied, I have been able to gather a trace with LTTng
and view it in LTTV. Next steps for LTTng support on sparc64 are to add
the syscall and trap instrumentation.
Thanks,
Mathieu
sparc: sys32.S incorrect compat-layer splice() system call
I think arch/sparc/kernel/sys32.S has an incorrect splice definition:
SIGN2(sys32_splice, sys_splice, %o0, %o1)
The splice() prototype looks like :
long splice(int fd_in, loff_t *off_in, int fd_out,
loff_t *off_out, size_t len, unsigned int flags);
So I think we should have :
SIGN2(sys32_splice, sys_splice, %o0, %o2)
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
CC: "David S. Miller" <davem@xxxxxxxxxxxxxxxx>
CC: Jakub Jelinek <jj@xxxxxxxxxxxxxx>
---
arch/sparc/kernel/sys32.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Index: linux-2.6-lttng/arch/sparc/kernel/sys32.S
===================================================================
--- linux-2.6-lttng.orig/arch/sparc/kernel/sys32.S 2009-08-18 21:21:20.000000000 -0400
+++ linux-2.6-lttng/arch/sparc/kernel/sys32.S 2009-08-18 21:56:47.000000000 -0400
@@ -134,7 +134,7 @@ SIGN1(sys32_getpeername, sys_getpeername
SIGN1(sys32_getsockname, sys_getsockname, %o0)
SIGN2(sys32_ioprio_get, sys_ioprio_get, %o0, %o1)
SIGN3(sys32_ioprio_set, sys_ioprio_set, %o0, %o1, %o2)
-SIGN2(sys32_splice, sys_splice, %o0, %o1)
+SIGN2(sys32_splice, sys_splice, %o0, %o2)
SIGN2(sys32_sync_file_range, compat_sync_file_range, %o0, %o5)
SIGN2(sys32_tee, sys_tee, %o0, %o1)
SIGN1(sys32_vmsplice, compat_sys_vmsplice, %o0)
--
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
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