From: Laszlo Ersek <lersek@redhat.com> To: Borislav Petkov <bp@alien8.de> Cc: edk2-devel@lists.sourceforge.net, David Woodhouse <dwmw2@infradead.org>, linux-efi@vger.kernel.org, lkml <linux-kernel@vger.kernel.org>, Gleb Natapov <gleb@redhat.com>, Matthew Garrett <mjg59@srcf.ucam.org> Subject: Re: [edk2] Corrupted EFI region Date: Mon, 05 Aug 2013 18:41:20 +0200 [thread overview] Message-ID: <51FFD5B0.9080000@redhat.com> (raw) In-Reply-To: <20130805161247.GF31845@pd.tnic> On 08/05/13 18:12, Borislav Petkov wrote: > On Mon, Aug 05, 2013 at 05:15:38PM +0200, Laszlo Ersek wrote: >> The current implementation (how pointers are converted) probably doesn't >> accommodate a second call. >> >> Of course you want to know why SetVirtualAddressMap() was designed like >> that... I didn't participate in the design so I don't know :) >> >> But, as I said, a kernel directly executing another kernel is an >> unexpected idea. IMHO the second kernel in question doesn't fit the UEFI >> phases at all. The OS booted like that (ie. the OS whose kernel is the >> 2nd (=kexec) kernel) never goes through SEC, PEI, DXE, BDS. > > Yes, the thing is, imposing unnecessary restrictions is very > counterproductive. And kexec is just an example here - if > SetVirtualAddressMap was callable an arbitrary number of times, this > whole work I'm doing is unnecessary. So I'm jumping through hoops just > to accomodate a braindead design. I doubt it was a deliberate restriction. More like, there was no incentive (... that the designers were aware of) *not* to design something easy (or easier) to implement. Your use case has come later. > This is what I cannot fathom in the face of people praising UEFI as the > solution to all problems. I agree that such people exist. I'm not one of them. >> BTW there's another point I'd like to ask about -- you're saying you >> see the region corruption during the same boot, from the first (early) >> memmap dump to the second one (when just about to enter virtual mode). >> But, is this one boot the very first boot, or the kexec one? > > No, kexec is not even involved yet. If you look at the timestamps, > there's 0.005 seconds between the two dumps during the *same* kernel > booting on the machine, baremetal, straight from grub. I didn't realize the timestamps survive kexec. (As far as I remember the kernels I played with kexec on didn't have the automatic timestamps yet in dmesg, but I might have messed up just as well...) Laszlo
WARNING: multiple messages have this Message-ID (diff)
From: Laszlo Ersek <lersek@redhat.com> To: Borislav Petkov <bp@alien8.de> Cc: linux-efi@vger.kernel.org, Gleb Natapov <gleb@redhat.com>, edk2-devel@lists.sourceforge.net, lkml <linux-kernel@vger.kernel.org>, David Woodhouse <dwmw2@infradead.org> Subject: Re: [edk2] Corrupted EFI region Date: Mon, 05 Aug 2013 18:41:20 +0200 [thread overview] Message-ID: <51FFD5B0.9080000@redhat.com> (raw) In-Reply-To: <20130805161247.GF31845@pd.tnic> On 08/05/13 18:12, Borislav Petkov wrote: > On Mon, Aug 05, 2013 at 05:15:38PM +0200, Laszlo Ersek wrote: >> The current implementation (how pointers are converted) probably doesn't >> accommodate a second call. >> >> Of course you want to know why SetVirtualAddressMap() was designed like >> that... I didn't participate in the design so I don't know :) >> >> But, as I said, a kernel directly executing another kernel is an >> unexpected idea. IMHO the second kernel in question doesn't fit the UEFI >> phases at all. The OS booted like that (ie. the OS whose kernel is the >> 2nd (=kexec) kernel) never goes through SEC, PEI, DXE, BDS. > > Yes, the thing is, imposing unnecessary restrictions is very > counterproductive. And kexec is just an example here - if > SetVirtualAddressMap was callable an arbitrary number of times, this > whole work I'm doing is unnecessary. So I'm jumping through hoops just > to accomodate a braindead design. I doubt it was a deliberate restriction. More like, there was no incentive (... that the designers were aware of) *not* to design something easy (or easier) to implement. Your use case has come later. > This is what I cannot fathom in the face of people praising UEFI as the > solution to all problems. I agree that such people exist. I'm not one of them. >> BTW there's another point I'd like to ask about -- you're saying you >> see the region corruption during the same boot, from the first (early) >> memmap dump to the second one (when just about to enter virtual mode). >> But, is this one boot the very first boot, or the kexec one? > > No, kexec is not even involved yet. If you look at the timestamps, > there's 0.005 seconds between the two dumps during the *same* kernel > booting on the machine, baremetal, straight from grub. I didn't realize the timestamps survive kexec. (As far as I remember the kernels I played with kexec on didn't have the automatic timestamps yet in dmesg, but I might have messed up just as well...) Laszlo ------------------------------------------------------------------------------ Get your SQL database under version control now! Version control is standard for application code, but databases havent caught up. So what steps can you take to put your SQL databases under version control? Why should you start doing it? Read more to find out. http://pubads.g.doubleclick.net/gampad/clk?id=49501711&iu=/4140/ostg.clktrk
next prev parent reply other threads:[~2013-08-05 16:39 UTC|newest] Thread overview: 108+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-07-31 20:54 Corrupted EFI region Borislav Petkov 2013-07-31 20:54 ` Borislav Petkov 2013-07-31 20:58 ` Matthew Garrett 2013-07-31 20:58 ` Matthew Garrett 2013-07-31 21:51 ` Borislav Petkov 2013-07-31 21:51 ` Borislav Petkov 2013-07-31 21:54 ` Matthew Garrett 2013-07-31 21:54 ` Matthew Garrett 2013-08-01 16:51 ` Borislav Petkov 2013-08-01 16:51 ` Borislav Petkov 2013-07-31 21:55 ` David Woodhouse 2013-07-31 21:55 ` David Woodhouse 2013-08-01 16:49 ` Borislav Petkov 2013-08-01 16:49 ` Borislav Petkov 2013-08-05 11:27 ` [edk2] " Laszlo Ersek 2013-08-05 11:27 ` Laszlo Ersek 2013-08-05 13:02 ` Borislav Petkov 2013-08-05 13:02 ` Borislav Petkov 2013-08-05 13:39 ` Laszlo Ersek 2013-08-05 13:39 ` Laszlo Ersek 2013-08-05 14:03 ` Borislav Petkov 2013-08-05 14:03 ` Borislav Petkov 2013-08-05 14:27 ` Laszlo Ersek 2013-08-05 14:27 ` Laszlo Ersek 2013-08-05 14:40 ` Borislav Petkov 2013-08-05 14:40 ` Borislav Petkov 2013-08-05 15:15 ` Laszlo Ersek 2013-08-05 15:15 ` Laszlo Ersek 2013-08-05 15:34 ` James Bottomley 2013-08-05 15:34 ` James Bottomley 2013-08-05 16:27 ` Laszlo Ersek 2013-08-05 16:27 ` Laszlo Ersek 2013-08-05 16:12 ` Borislav Petkov 2013-08-05 16:12 ` Borislav Petkov 2013-08-05 16:41 ` Laszlo Ersek [this message] 2013-08-05 16:41 ` Laszlo Ersek 2013-08-05 16:47 ` Borislav Petkov 2013-08-05 16:47 ` Borislav Petkov 2013-08-05 17:00 ` Kinney, Michael D 2013-08-05 17:00 ` Kinney, Michael D 2013-08-05 17:09 ` Laszlo Ersek 2013-08-05 17:09 ` Laszlo Ersek 2013-08-05 21:26 ` Laszlo Ersek 2013-08-05 21:26 ` Laszlo Ersek 2013-08-05 22:08 ` Borislav Petkov 2013-08-05 22:08 ` Borislav Petkov 2013-08-06 14:10 ` Borislav Petkov 2013-08-06 14:10 ` Borislav Petkov 2013-08-06 15:31 ` Laszlo Ersek 2013-08-06 15:31 ` Laszlo Ersek 2013-08-07 15:19 ` Borislav Petkov 2013-08-07 17:23 ` Andrew Fish 2013-08-07 17:23 ` Andrew Fish 2013-08-07 20:19 ` Matt Fleming 2013-08-07 20:19 ` Matt Fleming 2013-08-07 20:24 ` Matt Fleming 2013-08-07 20:24 ` Matt Fleming 2013-08-07 21:10 ` Andrew Fish 2013-08-07 21:10 ` Andrew Fish 2013-08-07 21:23 ` Matthew Garrett 2013-08-08 10:17 ` Matt Fleming 2013-08-08 10:17 ` Matt Fleming 2013-08-08 13:46 ` Andrew Fish 2013-08-08 13:46 ` Andrew Fish 2013-09-02 8:19 ` Matt Fleming 2013-09-02 8:19 ` Matt Fleming 2013-09-13 20:38 ` jerry.hoemann 2013-09-13 20:38 ` jerry.hoemann-VXdhtT5mjnY 2013-09-16 10:59 ` Matt Fleming 2013-09-16 10:59 ` Matt Fleming 2013-09-16 11:50 ` Laszlo Ersek 2013-09-16 11:50 ` Laszlo Ersek 2013-09-16 15:57 ` Josh Triplett 2013-09-16 15:57 ` Josh Triplett 2013-09-16 16:25 ` Laszlo Ersek 2013-09-16 16:25 ` Laszlo Ersek 2013-09-16 16:27 ` Matthew Garrett 2013-09-16 16:27 ` Matthew Garrett 2013-09-16 16:29 ` Josh Triplett 2013-09-16 16:29 ` Josh Triplett 2013-09-18 19:24 ` jerry.hoemann 2013-09-18 19:24 ` jerry.hoemann-VXdhtT5mjnY 2013-09-20 9:06 ` Matt Fleming 2013-09-20 9:06 ` Matt Fleming 2013-08-07 17:49 ` Laszlo Ersek 2013-08-07 17:49 ` Laszlo Ersek 2013-08-08 15:02 ` Borislav Petkov 2013-08-08 15:02 ` Borislav Petkov 2013-08-08 21:45 ` Brian J. Johnson 2013-08-08 21:45 ` Brian J. Johnson 2013-08-18 7:33 ` Jordan Justen 2013-08-18 7:33 ` Jordan Justen 2013-08-05 15:50 ` Andrew Fish 2013-08-05 15:50 ` Andrew Fish 2013-08-05 18:12 ` Borislav Petkov 2013-08-05 18:12 ` Borislav Petkov 2013-08-05 21:37 ` H. Peter Anvin 2013-08-05 21:37 ` H. Peter Anvin 2013-08-05 21:41 ` Borislav Petkov 2013-08-05 21:41 ` Borislav Petkov 2013-08-05 21:49 ` H. Peter Anvin 2013-08-05 21:49 ` H. Peter Anvin 2013-08-05 21:55 ` Laszlo Ersek 2013-08-05 21:55 ` Laszlo Ersek 2013-08-05 22:52 ` James Bottomley 2013-08-05 22:52 ` James Bottomley 2013-08-06 7:26 ` Laszlo Ersek 2013-08-06 7:26 ` Laszlo Ersek
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