[Crash-utility] patch to add vmss memory regions support
Dave Anderson
anderson at redhat.com
Tue Mar 24 18:52:02 UTC 2015
Dyno,
I haven't really begun to review the patch yet, but when I was checking
read_vmware_vmss() for the incorrect PAGE_SHIFT usage, I notice that this
change is also incorrect:
- if (fread(bufptr, 1 , cnt, vmss.dfp) != cnt)
- return READ_ERROR;
+ cnt = fread(bufptr, 1, cnt, vmss.dfp);
return cnt;
}
The readmem() function keys on READ_ERROR, SEEK_ERROR and PAGE_EXCLUDED,
and if none of those are returned, it presumes the read was successful.
See the READMEM() macro/call in the readmem() function.
Dave
----- Original Message -----
>
>
> ----- Original Message -----
> > Dave,
> > patch attached. thanks.
> > rgds,
> > Dyno
>
>
> OK thanks, but now can you re-work the patch so that crash builds
> cleanly with "make warn"? Here on an x86_64 with gcc-4.7.2:
>
> $ make warn
> TARGET: X86_64
> CRASH: 7.1.1rc12
> GDB: 7.6
>
> cc -c -g -DX86_64 -DLZO -DSNAPPY -DGDB_7_6 build_data.c -Wall -O2
> -Wstrict-prototypes -Wmissing-prototypes -fstack-protector
> -Wformat-security
> cc -c -g -DX86_64 -DLZO -DSNAPPY -DGDB_7_6 vmware_vmss.c -Wall -O2
> -Wstrict-prototypes -Wmissing-prototypes -fstack-protector
> -Wformat-security
> vmware_vmss.c: In function ‘vmware_vmss_init’:
> vmware_vmss.c:218:7: warning: dereferencing type-punned pointer will break
> strict-aliasing rules [-Wstrict-aliasing]
> vmware_vmss.c:222:7: warning: dereferencing type-punned pointer will break
> strict-aliasing rules [-Wstrict-aliasing]
> vmware_vmss.c:225:7: warning: dereferencing type-punned pointer will break
> strict-aliasing rules [-Wstrict-aliasing]
> vmware_vmss.c:228:7: warning: dereferencing type-punned pointer will break
> strict-aliasing rules [-Wstrict-aliasing]
> vmware_vmss.c:231:7: warning: dereferencing type-punned pointer will break
> strict-aliasing rules [-Wstrict-aliasing]
> ...
>
> And then for a quick sanity check, I noted that the patch won't even
> compile at all on an ARM64 machine:
>
> $ make warn
> TARGET: ARM64
> CRASH: 7.1.0
> GDB: 7.6
>
> cc -c -g -DARM64 -DGDB_7_6 build_data.c -Wall -O2 -Wstrict-prototypes
> -Wmissing-prototypes -fstack-protector -Wformat-security
> cc -c -g -DARM64 -DGDB_7_6 netdump.c -Wall -O2 -Wstrict-prototypes
> -Wmissing-prototypes -fstack-protector -Wformat-security
> cc -c -g -DARM64 -DGDB_7_6 vmware_vmss.c -Wall -O2 -Wstrict-prototypes
> -Wmissing-prototypes -fstack-protector -Wformat-security
> vmware_vmss.c: In function ‘vmware_vmss_init’:
> vmware_vmss.c:218:7: warning: dereferencing type-punned pointer will break
> strict-aliasing rules [-Wstrict-aliasing]
> vmss.regionscount = *(uint32_t*)val;
> ^
> vmware_vmss.c:222:7: warning: dereferencing type-punned pointer will break
> strict-aliasing rules [-Wstrict-aliasing]
> vmss.regions[idx[0]].startpagenum = *(uint32_t*)val;
> ^
> vmware_vmss.c:225:7: warning: dereferencing type-punned pointer will break
> strict-aliasing rules [-Wstrict-aliasing]
> vmss.regions[idx[0]].startppn = *(uint32_t*)val;
> ^
> vmware_vmss.c:228:7: warning: dereferencing type-punned pointer will break
> strict-aliasing rules [-Wstrict-aliasing]
> vmss.regions[idx[0]].size = *(uint32_t*)val;
> ^
> vmware_vmss.c:231:7: warning: dereferencing type-punned pointer will break
> strict-aliasing rules [-Wstrict-aliasing]
> vmss.alignmask = *(uint32_t*)val;
> ^
> vmware_vmss.c: In function ‘vmware_vmss_page_size’:
> vmware_vmss.c:277:9: error: ‘PAGE_SIZE’ undeclared (first use in this
> function)
> return PAGE_SIZE;
> ^
> vmware_vmss.c:277:9: note: each undeclared identifier is reported only once
> for each function it appears in
> vmware_vmss.c: In function ‘read_vmware_vmss’:
> vmware_vmss.c:287:37: error: ‘PAGE_SHIFT’ undeclared (first use in this
> function)
> uint32_t ppn = (uint32_t) (pos >> PAGE_SHIFT);
> ^
> vmware_vmss.c: In function ‘vmware_vmss_page_size’:
> vmware_vmss.c:278:1: warning: control reaches end of non-void function
> [-Wreturn-type]
> }
> ^
> make[4]: *** [vmware_vmss.o] Error 1
> make[3]: *** [gdb] Error 2
> make[2]: *** [rebuild] Error 2
> make[1]: *** [gdb_merge] Error 2
> make: *** [warn] Error 2
> $
>
> And that's because PAGE_SIZE is only #define'd in defs.h for x86_64, and
> and PAGE_SHIFT is only #define'd in defs.h for x86_64 and ppc32.
>
> There are machdep->pagesize and machdep->pageshift that get assigned for
> each architecture. So you could use machdep->pageshift in your patch
> to read_vmware_vmss().
>
>
> But then there's this:
>
> uint vmware_vmss_page_size(void)
> {
> - return 4096;
> + return PAGE_SIZE;
> }
>
> which is pretty much the wrong way to do it both before and after.
> I'm not sure how you want to handle it.
>
> Dave
>
>
>
>
>
>
>
> > On 3/24/15 10:00 AM, Dyno Hongjun Fu wrote:
> > > ---------- Forwarded message ----------
> > > From: Dave Anderson <anderson at redhat.com>
> > > Date: Tue, Mar 24, 2015 at 7:17 AM
> > > Subject: Re: [Crash-utility] patch to add vmss memory regions support
> > > To: "Discussion list for crash utility usage, maintenance and
> > > development" <crash-utility at redhat.com>
> > >
> > >
> > >
> > > Dyno,
> > >
> > > Can you re-post this path so that it applies cleanly to the
> > > current git repository? This is what happens:
> > >
> > > $ git clone
> > > https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_crash-2Dutility_crash.git&d=AwIBaQ&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=g2Vka_25x09RSowRkQw8pA&m=CMSBEaJrUe0l1I8xeRN7TmIsyloBPUmxxxRDdOkWC_0&s=urNZ6YRJ7FSXVWnWZBOKvR8FnqMpawcqdLe_2jNTvo0&e=
> > > Cloning into 'crash'...
> > > remote: Counting objects: 811, done.
> > > remote: Total 811 (delta 0), reused 0 (delta 0), pack-reused 811
> > > Receiving objects: 100% (811/811), 1.87 MiB | 1.04 MiB/s, done.
> > > Resolving deltas: 100% (532/532), done.
> > > $ cd crash
> > > $ patch -p1 < ../vmware_memory_region_support.patch
> > > patching file vmware_vmss.c
> > > Reversed (or previously applied) patch detected! Assume -R? [n] n
> > > Apply anyway? [n] y
> > > Hunk #1 succeeded at 42 with fuzz 2 (offset 2 lines).
> > > Hunk #2 succeeded at 141 (offset 2 lines).
> > > Hunk #3 succeeded at 164 (offset 2 lines).
> > > Hunk #4 succeeded at 192 (offset 2 lines).
> > > Hunk #5 succeeded at 217 (offset 2 lines).
> > > Hunk #6 FAILED at 256.
> > > Hunk #7 succeeded at 276 (offset 2 lines).
> > > 1 out of 7 hunks FAILED -- saving rejects to file vmware_vmss.c.rej
> > > patching file vmware_vmss.h
> > > $
> > >
> > > Thanks,
> > > Dave
> > >
> > >
> > > ----- Original Message -----
> > >> Dave,
> > >>
> > >> attached patch is to add vmss memroy regions support.
> > >>
> > >> There might be holes in the memory address saved for PCI etc.
> > >> In such case memory dump is divided into regions. Currently
> > >> up to 3 regions are supported.
> > >>
> > >> Memory dump larger than 3GB will have the first hole.
> > >> My dropbox space used up, I cannot attach a 4GB memory dump.
> > >> and here is how it looks like in the vmss meta data dump.
> > >>
> > >> 3GB:
> > >> ===
> > >> - Group: memory pos=0x1f6f6 size=0xc000090c
> > >> ------------------------------------
> > >> align_mask[0, 0] => 0x00ffff
> > >> regionsCount => 0x000000
> > >> Memory[0, 0] => BLOCK, pos=0x20000, size=0xc0000000
> > >>
> > >> 4GB:
> > >> ===
> > >> - Group: memory pos=0x1f6f6 size=0x10000090c
> > >> -----------------------------------
> > >> align_mask[0, 0] => 0x00ffff
> > >> regionsCount => 0x000002
> > >> regionPageNum[0] => 0x000000
> > >> regionPPN[0] => 0x000000
> > >> regionSize[0] => 0x0c0000
> > >> regionPageNum[1] => 0x0c0000
> > >> regionPPN[1] => 0x100000
> > >> regionSize[1] => 0x040000
> > >> Memory[0, 0] => BLOCK, pos=0x20000, size=0x100000000
> > >>
> > >> rgds,
> > >> Dyno
> > >>
> > >> --
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> > >
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