From: David Laight <David.Laight@ACULAB.COM>
To: "'Michal Suchánek'" <msuchanek@suse.de>,
"Petr Mladek" <pmladek@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
"linux-s390@vger.kernel.org" <linux-s390@vger.kernel.org>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Michal Hocko <mhocko@suse.cz>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Stephen Rothwell <sfr@ozlabs.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
"Tobin C . Harding" <me@tobin.cc>
Subject: RE: [PATCH] vsprintf: Do not break early boot with probing addresses
Date: Thu, 9 May 2019 13:46:59 +0000 [thread overview]
Message-ID: <8ad8bb83b7034f7e92df12040fb8c2c2@AcuMS.aculab.com> (raw)
Message-ID: <20190509134659.kYjGd-skkWNID8rAreeNzTDTLfzq382O0FQCZ5calZI@z> (raw)
In-Reply-To: <20190509153829.06319d0c@kitsune.suse.cz>
From: Michal Suchánek
> Sent: 09 May 2019 14:38
...
> > The problem is the combination of some new code called via printk(),
> > check_pointer() which calls probe_kernel_read(). That then calls
> > allow_user_access() (PPC_KUAP) and that uses mmu_has_feature() too early
> > (before we've patched features).
>
> There is early_mmu_has_feature for this case. mmu_has_feature does not
> work before patching so parts of kernel that can run before patching
> must use the early_ variant which actually runs code reading the
> feature bitmap to determine the answer.
Does the early_ variant get patched so the it is reasonably
efficient after the 'patching' is done?
Or should there be a third version which gets patched across?
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2019-05-09 13:46 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190509121923.aQycz_mOWrrZRdG61KMh7qtBiiaqDuu5CXB5Ufi79nE@z>
2019-05-09 12:19 ` [PATCH] vsprintf: Do not break early boot with probing addresses Petr Mladek
[not found] ` <20190509130512.eOpTHWX1Vw219J1juYw-SpeQRpBzQZT5CGSN2gh29i4@z>
2019-05-09 13:05 ` Andy Shevchenko
[not found] ` <20190509131357.ae3kG3RqVx9kjP66InzbRDur4-P1bAbE2QdMj6Mn17c@z>
2019-05-09 13:13 ` Steven Rostedt
[not found] ` <20190509140609.pGTLvlSQI_xy_YFvhBzkQV7ZWu_ABMDICwAH3s7J8IA@z>
2019-05-09 14:06 ` Petr Mladek
[not found] ` <20190509133829.35pSRgEMpcLhNbfDUK9sCV-aSZSNvQEOVDu8hmrRnzU@z>
2019-05-09 13:38 ` Michal Suchánek
[not found] ` <20190509134659.kYjGd-skkWNID8rAreeNzTDTLfzq382O0FQCZ5calZI@z>
2019-05-09 13:46 ` David Laight [this message]
2019-05-10 10:21 ` Michael Ellerman
[not found] ` <20190510043200.8FxCQhSO0N0LIZ4YtumRMpgw45VDU75TKeSE5eHU2dc@z>
2019-05-10 4:32 ` Sergey Senozhatsky
2019-05-10 4:47 ` Linus Torvalds
[not found] ` <20190510050709.ugUsmdWEg2-_zeuhzXY9dG3VOFvC7DcdjoUsQ1gSOxk@z>
2019-05-10 5:07 ` Sergey Senozhatsky
[not found] ` <20190510064124.q7J_CwuPPeHjW5ZMFj9t16uRiB6ATm6nxxi7Biu_ngY@z>
2019-05-10 6:41 ` Michael Ellerman
[not found] ` <20190510080602.36-virBOPDomDAXDbVYusr-C7NH4SabZGccCMnPdJH4@z>
2019-05-10 8:06 ` Petr Mladek
2019-05-10 8:16 ` Sergey Senozhatsky
[not found] ` <20190510084213.8Fn-MjbMg2bybTStBKHj9OvLB7rut0bqt0KPaIdXS6w@z>
2019-05-10 8:42 ` Petr Mladek
[not found] ` <20190510085121.odNKC0TIP5NjjMowx6VFDfGImLYzeJZz8lrq7Yx7_hk@z>
2019-05-10 8:51 ` Sergey Senozhatsky
[not found] ` <20190510144917.9fXSsk7NOInbDA76CH7cG3WBj0FI-4Dwb2Tk9_C4zpU@z>
2019-05-10 14:49 ` Petr Mladek
[not found] ` <20190510162401.zyjRI2h57ECWKi8XIr7nNNUOwR44kpMVP_pAyDYOETo@z>
2019-05-10 16:24 ` Steven Rostedt
[not found] ` <20190510163258.qn3246r2dHdhqWhvmxZO4mIbhuwcSMjfnXQQlH0ZaHs@z>
2019-05-10 16:32 ` Martin Schwidefsky
[not found] ` <20190510164058.TGQUcmQqwQN4_qlomMwU48TPGVQzXQVM4L1sbRoiVqY@z>
2019-05-10 16:40 ` Steven Rostedt
[not found] ` <20190510164548.hSfrXK8q_ZGsqqE57NiR7n0OFDEvIcwdE7j7PZU7lac@z>
2019-05-10 16:45 ` Martin Schwidefsky
[not found] ` <20190513122424.Bzyc5wNhgHc3y9K3Vn-j74_9etFbZZ5gQ1QPdKl6DWc@z>
2019-05-13 12:24 ` Petr Mladek
[not found] ` <20190510164134.MOFEXv4lZ0byKuO5xFyCeqdaA9zePgipycDNWtjfBrg@z>
2019-05-10 16:41 ` Andy Shevchenko
[not found] ` <20190510173529.XATeuZJ4qvPsIGIrHM2kfdN6CdMiyb6gddK2hUaBa-I@z>
2019-05-10 17:35 ` christophe leroy
[not found] ` <20190513085241.CwbAqRfT4AD-BNv6ycJNL377JFUjP7hKf_PblscZCMA@z>
2019-05-13 8:52 ` David Laight
[not found] ` <20190513091320.1ZqC-JL0QLpgZiAEDAqK_gfjSO6wDFbjpn4v4t2QXOE@z>
2019-05-13 9:13 ` Andy Shevchenko
[not found] ` <20190513124220.pxn2l_kLvtCUhSGnQPpm0fECHh3Y6INT5S5RWf6pfe4@z>
2019-05-13 12:42 ` Petr Mladek
[not found] ` <20190513141550.nMZbc9Db_wQfUJwYwkQTsbqWEg3wp15GgYxSKNUijyQ@z>
2019-05-13 14:15 ` Steven Rostedt
[not found] ` <20190514020730.g4cTS2GpqhzzEgKbRibvfxOK38Jika-NdjcqZLJn1As@z>
2019-05-14 2:07 ` Sergey Senozhatsky
[not found] ` <20190514022526.vllOcw77HB9TYfH3e8ZSGlZ1g_E72jw6dA10uIIz-Dw@z>
2019-05-14 2:25 ` Sergey Senozhatsky
[not found] ` <20190514082821.vHA7v2O08oEYQIonTCUC1XbIM9aVA42znGjzYx0yqEA@z>
2019-05-14 8:28 ` David Laight
[not found] ` <20190514090217.YS1_XeAyyiXu8TPl6BFDc3rpbtL4aynuSYfokOJWYaU@z>
2019-05-14 9:02 ` Geert Uytterhoeven
[not found] ` <20190514183751.e9m7K3oevIRrilsKNzAtPbZ1iFL7XriqpwHrBnk9krU@z>
2019-05-14 18:37 ` Steven Rostedt
[not found] ` <20190514191306.iYLu_pdr2N7Q3pR0cC87rvIUTuczSZBRSyh5RyX1ny0@z>
2019-05-14 19:13 ` Geert Uytterhoeven
[not found] ` <20190514193503.XdZN4DHnv7PT3ysPIU9r8z4k2mgdzV7WD0-q-GTF5Zk@z>
2019-05-14 19:35 ` Steven Rostedt
[not found] ` <20190515072305.E1DEATG-MTVuAOpUj2pEKMYi_9cV96M6GcmiMB3QY8Q@z>
2019-05-15 7:23 ` Geert Uytterhoeven
[not found] ` <20190515075339.CYb8ZQm6zt6Kfk3OqcAqbBwh7Xb51oxEZ6kRCINiTz8@z>
2019-05-15 7:53 ` Petr Mladek
[not found] ` <20190515062111.T5hZGjKZK2a2swDTBpkbB4UbIVTKWVNPATVUxxRnwVM@z>
2019-05-15 6:21 ` Sergey Senozhatsky
[not found] ` <20190515073542.1LbG-sjR-mgtUP_Qb2B1cDfKE6rXwecam2gTdfB60ro@z>
2019-05-15 7:35 ` Petr Mladek
2019-05-15 9:00 ` David Laight
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