[patch] Alter syscall.brk and syscall.mremap to support IA64

[Wenji Huang]

Lai Jiangshan wrote:

> Hi, all
>     In the current tapset, kernel function sys_brk and sys_mremap are
> used to probe syscall.brk and syscall.mremap. But on IA64, the entries
> of syscall brk and mremap are actually ia64_brk and ia64_mremap, but not
> sys_brk and sys_mremap. Though I think ia64's kernel function will be
> finally changed to sys_brk and sys_mremap, it will be a long time so it
> is inconvenient for users to probe these 2 syscalls on IA64. So I added
> the probe points to syscall.brk and syscall.mremap for IA64 as following:
>
> diff -Nur /usr/share/systemtap/tapset/syscalls.stp tapset/syscalls.stp
> --- /usr/share/systemtap/tapset/syscalls.stp    2007-09-18 
> 10:11:15.000000000 +0900
> +++ tapset/syscalls.stp    2007-09-18 12:07:19.000000000 +0900
> @@ -178,12 +178,14 @@
>
> # brk ________________________________________________________
> # unsigned long sys_brk(unsigned long brk)
> -probe syscall.brk = kernel.function("sys_brk") {
> +probe syscall.brk = kernel.function("sys_brk"),
> +        kernel.function("ia64_brk") ? {
>     name = "brk"
>     brk = $brk
>     argstr = sprintf("%p", brk)
> }

sys_brk is generic, use %( arch == "ia64" %? to make it optional. Of 
course, it is better to put architecture depended probe into the 
corresponding directory.

Regards,
wenji