[Crash-utility] [PATCH] crash-gcore-command extension module: ARM64 support

[Dave Anderson]

----- Original Message -----
> Hi Dave,
> 
> which glibc version are you using? for us, it seems /usr/include/sys/procfs.h
> is not included, we still met build error with your patch

The ARM64 machine I'm building on is based upon glibc-headers-2.17-55.11,
But /usr/include/sys/procfs.h has been part of glibc-headers since at
least glibc-headers-2.3.2-95.  So if I understand you correctly, does
the /usr/include/sys/uncontext.h *not* include <sys/procfs.h> on your
system?

> 
> so Lei and me made some patches to use the old way for ARM64, and also add
> compat mode support for ARM64

That certainly makes the patch much uglier.  Would it be possible to explicitly
#include <sys/procfs.h> encapsulated by #ifdef ARM64 in the relevant places?

> 
> these patches are verified on both ARM64 compat mode and ARM64, please help
> review, thanks

Look, we're getting ahead of things.  Let's defer to Daisuke to decide how he is
going to approach this first.

Dave


 
> Best Regards,
> Wei
> 
> -----Original Message-----
> From: crash-utility-bounces at redhat.com
> [mailto:crash-utility-bounces at redhat.com] On Behalf Of Dave Anderson
> Sent: Tuesday, July 29, 2014 8:31 PM
> To: HATAYAMA Daisuke
> Cc: crash-utility at redhat.com
> Subject: Re: [Crash-utility] [PATCH] crash-gcore-command extension module:
> ARM64 support
> 
> 
> 
> ----- Original Message -----
> > From: Dave Anderson <anderson at redhat.com>
> > Subject: [PATCH] crash-gcore-command extension module: ARM64 support
> > Date: Thu, 17 Jul 2014 12:04:45 -0400
> > 
> > > 
> > > 
> > > Hello Daisuke,
> > > 
> > 
> > Hello Dave,
> > 
> > Sorry for very late responce....
> > 
> > > Attached is a patch to introduce support for the ARM64 architecture
> > > for the gcore extension module.
> > > 
> > > The patch is fairly straight-forward other than the fact that on
> > > ARM64 machines, the chain of headers included from the crash
> > > utility's "defs.h" looks like this:
> > > 
> > >   /usr/include/crash/defs.h
> > >     /usr/include/signal.h
> > >       /usr/include/sys/ucontext.h
> > >         /usr/include/sys/procfs.h
> > > 
> > > The <sys/procfs.h> file defines several of the ELF-related
> > > structures that are hard-coded in gcore_defs.h, causing compile
> > > failures due to duplicate structure declarations.
> > > 
> > > Note that the <sys/ucontext.h> file on the other three architectures
> > > does not #include <sys/procfs.h> so there are no conflicts.  It
> > > would be possible to move all architectures to include
> > > <sys/procfs.h>, but for example, that would also bring in the
> > > <sys/user.h> definition of the user_regs_struct, which in turn
> > > causes a myriad of register name mismatches in gcore_x86.c.
> > > So for the sake of simplicity, wherever there is an ARM64-only
> > > duplicate structure or definition in gcore_defs.h, I've encapsulated them
> > > by:
> > > 
> > >   #if defined(X86) || defined(X86_64) || defined(ARM)
> > > 
> > 
> > Thanks for this explanation. I'll also try to investigate this.
> > 
> > > Also, there are two generic fixes, one where the gcore module fails
> > > on Linux 3.11 and later kernels due to a structure member name
> > > change, and another that changes the getopt() return variable to an
> > > "int" instead of a "char".
> > > 
> > > Here are the details:
> > >   
> > >   gcore.mk:
> > >   
> > >     - Introduce ARM64 as a supported architecture
> > >     - Add libgcore/gcore_arm64 to GCORE_CFILES
> > >   
> > >   gcore.c:
> > >   
> > >     - In cmd_gcore() change "c" type to "int" to correctly match
> > >       the return type of getopt(); without it, the while loop
> > >       spins indefinitely on ARM64.
> > 
> > >     - In gcore_offset_table_init(), account for the Linux 3.11
> > >       structure member name-change from ns_proxy.pid_ns to
> > >       ns_proxy.pid_ns_for_children; without it, the gcore command
> > >       fails during initialization.
> > 
> > I've already dealt with this locally, but thanks.
> > 
> > >   
> > >   libgcore/gcore_defs.h:
> > >   
> > >     - Add ARM64 ELF- and REGSET_VIEW-related #defines required for
> > >       each architecture.
> > >     - Account for variable page sizes in ARM64.
> > >     - Restrict the hard-coded ELF_NGREG, elf_siginfo, elf_prstatus,
> > >       __kernel_old_uid_t and __kernel_old_gid_t, and elf_prsinfo
> > >       definitions to X86, X86_64 and ARM architectures.
> > >     - Add ARM64 thread_struct_fpsmid_state and thread_struct_tp_value
> > >       offsets to gcore_offset_table.
> > >   
> > >   libgcore/gcore_coredump.c:
> > >   
> > >     - In fill_prstatus_note(), account for the ARM64 usage of
> > >       "user_pt_regs" structure instead of the "user_regs_struct"
> > >       used by the other architectures.
> > >   
> > >   libgcore/gcore_arm64.c:
> > >   
> > >     - Implement ARM64-specific user_regset and user_regset_view
> > >       structures and all required support functions.
> > >   
> > > Please accept these changes into an new package version.
> > >   
> > 
> > I'll commit these into my local repository with some changes for ease
> > of my maintainance purpose. Maybe, I'll ask you to review the changed
> > version.
> 
> Excellent -- thanks!  I thought I'd lost you!
> 
> Dave
> 
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