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author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2015-02-18 00:58:35 +0100 |
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committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2015-02-18 00:58:35 +0100 |
commit | 49a086299e047b18280457b654790ef4a2e5abfa (patch) | |
tree | c2b29e0734d560ce4f58c6945390650b5cac8a1b /open_issues/vm_map_kernel_bug.mdwn | |
parent | e2b3602ea241cd0f6bc3db88bf055bee459028b6 (diff) | |
download | web-49a086299e047b18280457b654790ef4a2e5abfa.tar.gz web-49a086299e047b18280457b654790ef4a2e5abfa.tar.bz2 web-49a086299e047b18280457b654790ef4a2e5abfa.zip |
Revert "rename open_issues.mdwn to service_solahart_jakarta_selatan__082122541663.mdwn"
This reverts commit 95878586ec7611791f4001a4ee17abf943fae3c1.
Diffstat (limited to 'open_issues/vm_map_kernel_bug.mdwn')
-rw-r--r-- | open_issues/vm_map_kernel_bug.mdwn | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/open_issues/vm_map_kernel_bug.mdwn b/open_issues/vm_map_kernel_bug.mdwn new file mode 100644 index 00000000..159e9d04 --- /dev/null +++ b/open_issues/vm_map_kernel_bug.mdwn @@ -0,0 +1,71 @@ +[[!meta copyright="Copyright © 2012, 2013 Free Software Foundation, Inc."]] + +[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable +id="license" text="Permission is granted to copy, distribute and/or modify this +document under the terms of the GNU Free Documentation License, Version 1.2 or +any later version published by the Free Software Foundation; with no Invariant +Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license +is included in the section entitled [[GNU Free Documentation +License|/fdl]]."]]"""]] + +[[!tag open_issue_glibc open_issue_gnumach]] + + +# IRC, frenode, #hurd, 2012-11-04 + + <tschwinge> braunr, pinotree, youpi: Has either of you already figured out + what [glibc]/sysdeps/mach/hurd/dl-sysdep.c:fmh »XXX loser kludge for + vm_map kernel bug« is about? + <pinotree> tschwinge: ETOOLOWLEVELFORME :) + <pinotree> tschwinge: 5bf62f2d3a8af353fac661b224fc1604d4de51ea added it + <braunr> tschwinge: no, but that looks interesting + <braunr> i'll have a look later + <tschwinge> Heh, "interesting". ;-) + <tschwinge> It seems related to vm_map's mask + parameter/ELF_MACHINE_USER_ADDRESS_MASK, though the latter in only used + in the mmap implementation in sysdeps/mach/hurd/dl-sysdep.c (in mmap.c, 0 + is passed; perhaps due to the bug?). + <tschwinge> braunr: Anyway, I'd already welcome a patch to simply turn that + into a more comprehensible form. + <braunr> tschwinge: ELF_MACHINE_USER_ADDRESS_MASK is defined as "Mask + identifying addresses reserved for the user program, where the dynamic + linker should not map anything." + <braunr> about the vm_map parameter, which is a mask, it is described by + "Bits asserted in this mask must not be asserted in the address returned" + <braunr> so it's an alignment constraint + <braunr> the kludge disables alignment, apparently because gnumach doesn't + handle them correctly for some cases + <tschwinge> braunr: But ELF_MACHINE_USER_ADDRESS_MASK is 0xf8000000, so I'd + rather assume this means to restrict to addresses lower than 0xf8000000. + (What are whigher ones reserved for?) + <braunr> tschwinge: the linker i suppose + <braunr> tschwinge: sorry, i don't understand what + ELF_MACHINE_USER_ADDRESS_MASK really is used for :/ + <braunr> tschwinge: it looks unused for the other systems + <braunr> tschwinge: i guess it's just one way to partition the address + space, so that the linker knows where to load libraries and mmap can + still allocate large contiguous blocks + <braunr> tschwinge: 0xf8000000 means each "chunk" of linker/other blocks + are 128 MiB large + <tschwinge> braunr: OK, thanks for looking. I guess I'll ask Roland about + it. + <braunr> it could be that gnumach isn't good at aligning to large values + +[[!message-id "87fw4pb4c7.fsf@kepler.schwinge.homeip.net"]] + + +# IRC, frenode, #hurd, 2013-01-22 + +In context of [[libpthread]]. + + <braunr> pinotree: do you understand what the fmh function does in + sysdeps/mach/hurd/dl-sysdep.c ? + <braunr> ok i understand what it does + <braunr> and youpi has changed the code, so he does too + <braunr> youpi: do you have a suggestion about how to solve this issue in + the fmh function ? + <youpi> do we remember which bug it's after? + <braunr> what do you mean ? + <braunr> ah + <braunr> no :/ + <braunr> it could be a good occasion to get rid of it, yes |