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Re: manual SyS_foo management is unnecessary?


On Tue, Jun 15, 2010 at 10:45:56AM -0700, Josh Stone wrote:
> On 06/14/2010 10:19 PM, Ananth N Mavinakayanahalli wrote:
> > For the normal case (kernel.function) case, when SYSCALL_WRAPPERS were
> > introduced, every one of the syscall tests would fail with 'no match for
> > probe point sys_open' and the like. This was because the sys_ variants
> > would be inlined and stap wouldn't find them. Has this changed?
> 
> It's not that sys_ is an inline.  There are three variants:
> - sys_foo(typed args), declared and aliased to SyS_foo
> - SyS_foo(long args), defined to cast each arg in a call to SYSC_foo
> - inline SYSC_foo(typed args), the real syscall function
> 
> Your commit 132c337 in February 2009 added all the SyS_ variants to the
> syscalls tapset, which was necessary at the time because stap didn't
> know how to find the alias-only sys_ functions.
> 
> My commit 1c6b77e in July 2009 started resolving symbol aliases, which
> was specifically done for libraries like libc, though it applies to any
> ELF object.  It wasn't until now that I realized that this applies to
> the sys_foo names too.

OK then, please go ahead and commit the change.

Thanks,
Ananth


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