* [PATCH v2] x86/efi: Disable runtime services on kexec kernel if booted with efi=old_map
@ 2017-05-17 1:14 Sai Praneeth Prakhya
[not found] ` <1494983663-29286-1-git-send-email-sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
0 siblings, 1 reply; 5+ messages in thread
From: Sai Praneeth Prakhya @ 2017-05-17 1:14 UTC (permalink / raw)
To: linux-efi-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA
Cc: Sai Praneeth, Borislav Petkov, Ricardo Neri, Matt Fleming,
Ard Biesheuvel, Ravi Shankar, Lee Chun-Yi, Dave Young
From: Sai Praneeth <sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Booting kexec kernel with "efi=old_map" in kernel command line hits
kernel panic as shown below.
[0.001000] BUG: unable to handle kernel paging request at ffff88007fe78070
[0.001000] IP: virt_efi_set_variable.part.7+0x63/0x1b0
[0.001000] PGD 7ea28067
[0.001000] PUD 7ea2b067
[0.001000] PMD 7ea2d067
[0.001000] PTE 0
[0.001000]
[0.001000] Oops: 0000 [#1] SMP
[0.001000] Modules linked in:
[0.001000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc2-yocto-standard+ #229
[0.001000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
[0.001000] task: ffffffff82022500 task.stack: ffffffff82000000
[0.001000] RIP: 0010:virt_efi_set_variable.part.7+0x63/0x1b0
[0.001000] RSP: 0000:ffffffff82003dc0 EFLAGS: 00010246
[0.001000] RAX: ffff88007fe78018 RBX: ffffffff82050300 RCX: 0000000000000007
[0.001000] RDX: ffffffff82003e50 RSI: ffffffff82050300 RDI: ffffffff82050300
[0.001000] RBP: ffffffff82003e08 R08: 0000000000000000 R09: 0000000000000000
[0.001000] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82003e50
[0.001000] R13: 0000000000000007 R14: 0000000000000246 R15: 0000000000000000
[0.001000] FS: 0000000000000000(0000) GS:ffff88007fa00000(0000) knlGS:0000000000000000
[0.001000] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[0.001000] CR2: ffff88007fe78070 CR3: 000000007da1d000 CR4: 00000000000006b0
[0.001000] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[0.001000] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[0.001000] Call Trace:
[0.001000] virt_efi_set_variable+0x5d/0x70
[0.001000] efi_delete_dummy_variable+0x7a/0x80
[0.001000] efi_enter_virtual_mode+0x3f6/0x4a7
[0.001000] start_kernel+0x375/0x400
[0.001000] x86_64_start_reservations+0x2a/0x2c
[0.001000] x86_64_start_kernel+0x168/0x176
[0.001000] start_cpu+0x14/0x14
[0.001000] Code: 04 b0 84 ff 80 3d c5 56 b3 00 00 4c 8b 44 24 08 75
6b 9c 41 5e 48 8b 05 9c 78 99 00 4d 89 c1 48 89 de 4d 89 f8 44 89 e9 4c
89 e2 <48> 8b 40 58 48 8b 78 58 e8 b0 2d 88 ff 48 c7 c6 b6 1d f4 81 4c
[0.001000] RIP: virt_efi_set_variable.part.7+0x63/0x1b0 RSP: ffffffff82003dc0
[0.001000] CR2: ffff88007fe78070
[0.001000] ---[ end trace 0000000000000000 ]---
[0.001000] Kernel panic - not syncing: Attempted to kill the idle task!
[0.001000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task!
[efi=old_map was never intended to work with kexec. The problem with
using efi=old_map is that the virtual addresses are assigned from the
memory region used by other kernel mappings; vmalloc() space.
Potentially there could be collisions when booting kexec if something
else is mapped at the virtual address we allocated for runtime service
regions in the initial boot] - Matt Fleming
Since kexec was never intended to work with efi=old_map, disable
runtime services in kexec if booted with efi=old_map, so that we don't
panic.
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: Borislav Petkov <bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org>
Cc: Ricardo Neri <ricardo.neri-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org>
Cc: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: Ravi Shankar <ravi.v.shankar-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: Lee Chun-Yi <jlee-IBi9RG/b67k@public.gmane.org>
Cc: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Changes since v1:
Don't fix the panic, because this was never intended to work.
---
arch/x86/platform/efi/efi.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 87835c97611f..627b7b86f369 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -827,9 +827,11 @@ static void __init kexec_enter_virtual_mode(void)
/*
* We don't do virtual mode, since we don't do runtime services, on
- * non-native EFI
+ * non-native EFI. With efi=old_map, we don't do runtime services in
+ * kexec kernel because in the initial boot something else might
+ * have been mapped at these virtual addresses.
*/
- if (!efi_is_native()) {
+ if (!efi_is_native() || efi_enabled(EFI_OLD_MEMMAP)) {
efi_memmap_unmap();
clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
return;
--
2.1.4
^ permalink raw reply related [flat|nested] 5+ messages in thread[parent not found: <1494983663-29286-1-git-send-email-sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]
* Re: [PATCH v2] x86/efi: Disable runtime services on kexec kernel if booted with efi=old_map [not found] ` <1494983663-29286-1-git-send-email-sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> @ 2017-05-17 1:57 ` Dave Young [not found] ` <20170517015740.GA9562-0VdLhd/A9Pl+NNSt+8eSiB/sF2h8X+2i0E9HWUfgJXw@public.gmane.org> 2017-05-17 7:29 ` joeyli 2017-05-25 11:58 ` Matt Fleming 2 siblings, 1 reply; 5+ messages in thread From: Dave Young @ 2017-05-17 1:57 UTC (permalink / raw) To: Sai Praneeth Prakhya Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA, linux-kernel-u79uwXL29TY76Z2rM5mHXA, Borislav Petkov, Ricardo Neri, Matt Fleming, Ard Biesheuvel, Ravi Shankar, Lee Chun-Yi Hi Sai, On 05/16/17 at 06:14pm, Sai Praneeth Prakhya wrote: > From: Sai Praneeth <sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > > Booting kexec kernel with "efi=old_map" in kernel command line hits > kernel panic as shown below. > > [0.001000] BUG: unable to handle kernel paging request at ffff88007fe78070 > [0.001000] IP: virt_efi_set_variable.part.7+0x63/0x1b0 > [0.001000] PGD 7ea28067 > [0.001000] PUD 7ea2b067 > [0.001000] PMD 7ea2d067 > [0.001000] PTE 0 > [0.001000] > [0.001000] Oops: 0000 [#1] SMP > [0.001000] Modules linked in: > [0.001000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc2-yocto-standard+ #229 > [0.001000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 > [0.001000] task: ffffffff82022500 task.stack: ffffffff82000000 > [0.001000] RIP: 0010:virt_efi_set_variable.part.7+0x63/0x1b0 > [0.001000] RSP: 0000:ffffffff82003dc0 EFLAGS: 00010246 > [0.001000] RAX: ffff88007fe78018 RBX: ffffffff82050300 RCX: 0000000000000007 > [0.001000] RDX: ffffffff82003e50 RSI: ffffffff82050300 RDI: ffffffff82050300 > [0.001000] RBP: ffffffff82003e08 R08: 0000000000000000 R09: 0000000000000000 > [0.001000] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82003e50 > [0.001000] R13: 0000000000000007 R14: 0000000000000246 R15: 0000000000000000 > [0.001000] FS: 0000000000000000(0000) GS:ffff88007fa00000(0000) knlGS:0000000000000000 > [0.001000] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [0.001000] CR2: ffff88007fe78070 CR3: 000000007da1d000 CR4: 00000000000006b0 > [0.001000] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [0.001000] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [0.001000] Call Trace: > [0.001000] virt_efi_set_variable+0x5d/0x70 > [0.001000] efi_delete_dummy_variable+0x7a/0x80 > [0.001000] efi_enter_virtual_mode+0x3f6/0x4a7 > [0.001000] start_kernel+0x375/0x400 > [0.001000] x86_64_start_reservations+0x2a/0x2c > [0.001000] x86_64_start_kernel+0x168/0x176 > [0.001000] start_cpu+0x14/0x14 > [0.001000] Code: 04 b0 84 ff 80 3d c5 56 b3 00 00 4c 8b 44 24 08 75 > 6b 9c 41 5e 48 8b 05 9c 78 99 00 4d 89 c1 48 89 de 4d 89 f8 44 89 e9 4c > 89 e2 <48> 8b 40 58 48 8b 78 58 e8 b0 2d 88 ff 48 c7 c6 b6 1d f4 81 4c > [0.001000] RIP: virt_efi_set_variable.part.7+0x63/0x1b0 RSP: ffffffff82003dc0 > [0.001000] CR2: ffff88007fe78070 > [0.001000] ---[ end trace 0000000000000000 ]--- > [0.001000] Kernel panic - not syncing: Attempted to kill the idle task! > [0.001000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! > > [efi=old_map was never intended to work with kexec. The problem with > using efi=old_map is that the virtual addresses are assigned from the > memory region used by other kernel mappings; vmalloc() space. > Potentially there could be collisions when booting kexec if something > else is mapped at the virtual address we allocated for runtime service > regions in the initial boot] - Matt Fleming > > Since kexec was never intended to work with efi=old_map, disable > runtime services in kexec if booted with efi=old_map, so that we don't > panic. > > Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > Cc: Borislav Petkov <bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org> > Cc: Ricardo Neri <ricardo.neri-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > Cc: Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org> > Cc: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> > Cc: Ravi Shankar <ravi.v.shankar-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > Cc: Lee Chun-Yi <jlee-IBi9RG/b67k@public.gmane.org> > Cc: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> > > Changes since v1: > Don't fix the panic, because this was never intended to work. > --- > arch/x86/platform/efi/efi.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c > index 87835c97611f..627b7b86f369 100644 > --- a/arch/x86/platform/efi/efi.c > +++ b/arch/x86/platform/efi/efi.c > @@ -827,9 +827,11 @@ static void __init kexec_enter_virtual_mode(void) > > /* > * We don't do virtual mode, since we don't do runtime services, on > - * non-native EFI > + * non-native EFI. With efi=old_map, we don't do runtime services in > + * kexec kernel because in the initial boot something else might > + * have been mapped at these virtual addresses. > */ > - if (!efi_is_native()) { > + if (!efi_is_native() || efi_enabled(EFI_OLD_MEMMAP)) { > efi_memmap_unmap(); > clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); > return; > -- > 2.1.4 > Suppose it has passed the test on your hardware: Acked-by: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Thanks Dave ^ permalink raw reply [flat|nested] 5+ messages in thread
[parent not found: <20170517015740.GA9562-0VdLhd/A9Pl+NNSt+8eSiB/sF2h8X+2i0E9HWUfgJXw@public.gmane.org>]
* Re: [PATCH v2] x86/efi: Disable runtime services on kexec kernel if booted with efi=old_map [not found] ` <20170517015740.GA9562-0VdLhd/A9Pl+NNSt+8eSiB/sF2h8X+2i0E9HWUfgJXw@public.gmane.org> @ 2017-05-17 1:59 ` Sai Praneeth Prakhya 0 siblings, 0 replies; 5+ messages in thread From: Sai Praneeth Prakhya @ 2017-05-17 1:59 UTC (permalink / raw) To: Dave Young Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA, linux-kernel-u79uwXL29TY76Z2rM5mHXA, Borislav Petkov, Ricardo Neri, Matt Fleming, Ard Biesheuvel, Ravi Shankar, Lee Chun-Yi On Wed, 2017-05-17 at 09:57 +0800, Dave Young wrote: > Hi Sai, > On 05/16/17 at 06:14pm, Sai Praneeth Prakhya wrote: > > From: Sai Praneeth <sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > > > > Booting kexec kernel with "efi=old_map" in kernel command line hits > > kernel panic as shown below. > > > > [0.001000] BUG: unable to handle kernel paging request at ffff88007fe78070 > > [0.001000] IP: virt_efi_set_variable.part.7+0x63/0x1b0 > > [0.001000] PGD 7ea28067 > > [0.001000] PUD 7ea2b067 > > [0.001000] PMD 7ea2d067 > > [0.001000] PTE 0 > > [0.001000] > > [0.001000] Oops: 0000 [#1] SMP > > [0.001000] Modules linked in: > > [0.001000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc2-yocto-standard+ #229 > > [0.001000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 > > [0.001000] task: ffffffff82022500 task.stack: ffffffff82000000 > > [0.001000] RIP: 0010:virt_efi_set_variable.part.7+0x63/0x1b0 > > [0.001000] RSP: 0000:ffffffff82003dc0 EFLAGS: 00010246 > > [0.001000] RAX: ffff88007fe78018 RBX: ffffffff82050300 RCX: 0000000000000007 > > [0.001000] RDX: ffffffff82003e50 RSI: ffffffff82050300 RDI: ffffffff82050300 > > [0.001000] RBP: ffffffff82003e08 R08: 0000000000000000 R09: 0000000000000000 > > [0.001000] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82003e50 > > [0.001000] R13: 0000000000000007 R14: 0000000000000246 R15: 0000000000000000 > > [0.001000] FS: 0000000000000000(0000) GS:ffff88007fa00000(0000) knlGS:0000000000000000 > > [0.001000] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > [0.001000] CR2: ffff88007fe78070 CR3: 000000007da1d000 CR4: 00000000000006b0 > > [0.001000] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > > [0.001000] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > [0.001000] Call Trace: > > [0.001000] virt_efi_set_variable+0x5d/0x70 > > [0.001000] efi_delete_dummy_variable+0x7a/0x80 > > [0.001000] efi_enter_virtual_mode+0x3f6/0x4a7 > > [0.001000] start_kernel+0x375/0x400 > > [0.001000] x86_64_start_reservations+0x2a/0x2c > > [0.001000] x86_64_start_kernel+0x168/0x176 > > [0.001000] start_cpu+0x14/0x14 > > [0.001000] Code: 04 b0 84 ff 80 3d c5 56 b3 00 00 4c 8b 44 24 08 75 > > 6b 9c 41 5e 48 8b 05 9c 78 99 00 4d 89 c1 48 89 de 4d 89 f8 44 89 e9 4c > > 89 e2 <48> 8b 40 58 48 8b 78 58 e8 b0 2d 88 ff 48 c7 c6 b6 1d f4 81 4c > > [0.001000] RIP: virt_efi_set_variable.part.7+0x63/0x1b0 RSP: ffffffff82003dc0 > > [0.001000] CR2: ffff88007fe78070 > > [0.001000] ---[ end trace 0000000000000000 ]--- > > [0.001000] Kernel panic - not syncing: Attempted to kill the idle task! > > [0.001000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! > > > > [efi=old_map was never intended to work with kexec. The problem with > > using efi=old_map is that the virtual addresses are assigned from the > > memory region used by other kernel mappings; vmalloc() space. > > Potentially there could be collisions when booting kexec if something > > else is mapped at the virtual address we allocated for runtime service > > regions in the initial boot] - Matt Fleming > > > > Since kexec was never intended to work with efi=old_map, disable > > runtime services in kexec if booted with efi=old_map, so that we don't > > panic. > > > > Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > > Cc: Borislav Petkov <bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org> > > Cc: Ricardo Neri <ricardo.neri-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > > Cc: Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org> > > Cc: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> > > Cc: Ravi Shankar <ravi.v.shankar-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > > Cc: Lee Chun-Yi <jlee-IBi9RG/b67k@public.gmane.org> > > Cc: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> > > > > Changes since v1: > > Don't fix the panic, because this was never intended to work. > > --- > > arch/x86/platform/efi/efi.c | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c > > index 87835c97611f..627b7b86f369 100644 > > --- a/arch/x86/platform/efi/efi.c > > +++ b/arch/x86/platform/efi/efi.c > > @@ -827,9 +827,11 @@ static void __init kexec_enter_virtual_mode(void) > > > > /* > > * We don't do virtual mode, since we don't do runtime services, on > > - * non-native EFI > > + * non-native EFI. With efi=old_map, we don't do runtime services in > > + * kexec kernel because in the initial boot something else might > > + * have been mapped at these virtual addresses. > > */ > > - if (!efi_is_native()) { > > + if (!efi_is_native() || efi_enabled(EFI_OLD_MEMMAP)) { > > efi_memmap_unmap(); > > clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); > > return; > > -- > > 2.1.4 > > > > Suppose it has passed the test on your hardware: > Acked-by: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> > Thanks Dave! Haha... yes. I tested on qemu with OVMF > Thanks > Dave Regards, Sai ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] x86/efi: Disable runtime services on kexec kernel if booted with efi=old_map [not found] ` <1494983663-29286-1-git-send-email-sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> 2017-05-17 1:57 ` Dave Young @ 2017-05-17 7:29 ` joeyli 2017-05-25 11:58 ` Matt Fleming 2 siblings, 0 replies; 5+ messages in thread From: joeyli @ 2017-05-17 7:29 UTC (permalink / raw) To: Sai Praneeth Prakhya Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA, linux-kernel-u79uwXL29TY76Z2rM5mHXA, Borislav Petkov, Ricardo Neri, Matt Fleming, Ard Biesheuvel, Ravi Shankar, Dave Young On Tue, May 16, 2017 at 06:14:23PM -0700, Sai Praneeth Prakhya wrote: > From: Sai Praneeth <sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > > Booting kexec kernel with "efi=old_map" in kernel command line hits > kernel panic as shown below. > > [0.001000] BUG: unable to handle kernel paging request at ffff88007fe78070 > [0.001000] IP: virt_efi_set_variable.part.7+0x63/0x1b0 > [0.001000] PGD 7ea28067 > [0.001000] PUD 7ea2b067 > [0.001000] PMD 7ea2d067 > [0.001000] PTE 0 > [0.001000] > [0.001000] Oops: 0000 [#1] SMP > [0.001000] Modules linked in: > [0.001000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc2-yocto-standard+ #229 > [0.001000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 > [0.001000] task: ffffffff82022500 task.stack: ffffffff82000000 > [0.001000] RIP: 0010:virt_efi_set_variable.part.7+0x63/0x1b0 > [0.001000] RSP: 0000:ffffffff82003dc0 EFLAGS: 00010246 > [0.001000] RAX: ffff88007fe78018 RBX: ffffffff82050300 RCX: 0000000000000007 > [0.001000] RDX: ffffffff82003e50 RSI: ffffffff82050300 RDI: ffffffff82050300 > [0.001000] RBP: ffffffff82003e08 R08: 0000000000000000 R09: 0000000000000000 > [0.001000] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82003e50 > [0.001000] R13: 0000000000000007 R14: 0000000000000246 R15: 0000000000000000 > [0.001000] FS: 0000000000000000(0000) GS:ffff88007fa00000(0000) knlGS:0000000000000000 > [0.001000] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [0.001000] CR2: ffff88007fe78070 CR3: 000000007da1d000 CR4: 00000000000006b0 > [0.001000] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [0.001000] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [0.001000] Call Trace: > [0.001000] virt_efi_set_variable+0x5d/0x70 > [0.001000] efi_delete_dummy_variable+0x7a/0x80 > [0.001000] efi_enter_virtual_mode+0x3f6/0x4a7 > [0.001000] start_kernel+0x375/0x400 > [0.001000] x86_64_start_reservations+0x2a/0x2c > [0.001000] x86_64_start_kernel+0x168/0x176 > [0.001000] start_cpu+0x14/0x14 > [0.001000] Code: 04 b0 84 ff 80 3d c5 56 b3 00 00 4c 8b 44 24 08 75 > 6b 9c 41 5e 48 8b 05 9c 78 99 00 4d 89 c1 48 89 de 4d 89 f8 44 89 e9 4c > 89 e2 <48> 8b 40 58 48 8b 78 58 e8 b0 2d 88 ff 48 c7 c6 b6 1d f4 81 4c > [0.001000] RIP: virt_efi_set_variable.part.7+0x63/0x1b0 RSP: ffffffff82003dc0 > [0.001000] CR2: ffff88007fe78070 > [0.001000] ---[ end trace 0000000000000000 ]--- > [0.001000] Kernel panic - not syncing: Attempted to kill the idle task! > [0.001000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! > > [efi=old_map was never intended to work with kexec. The problem with > using efi=old_map is that the virtual addresses are assigned from the > memory region used by other kernel mappings; vmalloc() space. > Potentially there could be collisions when booting kexec if something > else is mapped at the virtual address we allocated for runtime service > regions in the initial boot] - Matt Fleming > > Since kexec was never intended to work with efi=old_map, disable > runtime services in kexec if booted with efi=old_map, so that we don't > panic. > > Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > Cc: Borislav Petkov <bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org> > Cc: Ricardo Neri <ricardo.neri-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > Cc: Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org> > Cc: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> > Cc: Ravi Shankar <ravi.v.shankar-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > Cc: Lee Chun-Yi <jlee-IBi9RG/b67k@public.gmane.org> > Cc: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> > > Changes since v1: > Don't fix the panic, because this was never intended to work. I tested this patch on OVMF and Acer UEFI laptop. It works to me for efi=old_map with crash kernel. Tested-by: "Lee, Chun-Yi" <jlee-IBi9RG/b67k@public.gmane.org> > --- > arch/x86/platform/efi/efi.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c > index 87835c97611f..627b7b86f369 100644 > --- a/arch/x86/platform/efi/efi.c > +++ b/arch/x86/platform/efi/efi.c > @@ -827,9 +827,11 @@ static void __init kexec_enter_virtual_mode(void) > > /* > * We don't do virtual mode, since we don't do runtime services, on > - * non-native EFI > + * non-native EFI. With efi=old_map, we don't do runtime services in > + * kexec kernel because in the initial boot something else might > + * have been mapped at these virtual addresses. > */ > - if (!efi_is_native()) { > + if (!efi_is_native() || efi_enabled(EFI_OLD_MEMMAP)) { > efi_memmap_unmap(); > clear_bit(EFI_RUNTIME_SERVICES, &efi.flags); > return; > -- > 2.1.4 > Thanks a lot! Joey Lee ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] x86/efi: Disable runtime services on kexec kernel if booted with efi=old_map [not found] ` <1494983663-29286-1-git-send-email-sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> 2017-05-17 1:57 ` Dave Young 2017-05-17 7:29 ` joeyli @ 2017-05-25 11:58 ` Matt Fleming 2 siblings, 0 replies; 5+ messages in thread From: Matt Fleming @ 2017-05-25 11:58 UTC (permalink / raw) To: Sai Praneeth Prakhya Cc: linux-efi-u79uwXL29TY76Z2rM5mHXA, linux-kernel-u79uwXL29TY76Z2rM5mHXA, Borislav Petkov, Ricardo Neri, Ard Biesheuvel, Ravi Shankar, Lee Chun-Yi, Dave Young On Tue, 16 May, at 06:14:23PM, Sai Praneeth Prakhya wrote: > From: Sai Praneeth <sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > > Booting kexec kernel with "efi=old_map" in kernel command line hits > kernel panic as shown below. > > [0.001000] BUG: unable to handle kernel paging request at ffff88007fe78070 > [0.001000] IP: virt_efi_set_variable.part.7+0x63/0x1b0 > [0.001000] PGD 7ea28067 > [0.001000] PUD 7ea2b067 > [0.001000] PMD 7ea2d067 > [0.001000] PTE 0 > [0.001000] > [0.001000] Oops: 0000 [#1] SMP > [0.001000] Modules linked in: > [0.001000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc2-yocto-standard+ #229 > [0.001000] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 > [0.001000] task: ffffffff82022500 task.stack: ffffffff82000000 > [0.001000] RIP: 0010:virt_efi_set_variable.part.7+0x63/0x1b0 > [0.001000] RSP: 0000:ffffffff82003dc0 EFLAGS: 00010246 > [0.001000] RAX: ffff88007fe78018 RBX: ffffffff82050300 RCX: 0000000000000007 > [0.001000] RDX: ffffffff82003e50 RSI: ffffffff82050300 RDI: ffffffff82050300 > [0.001000] RBP: ffffffff82003e08 R08: 0000000000000000 R09: 0000000000000000 > [0.001000] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82003e50 > [0.001000] R13: 0000000000000007 R14: 0000000000000246 R15: 0000000000000000 > [0.001000] FS: 0000000000000000(0000) GS:ffff88007fa00000(0000) knlGS:0000000000000000 > [0.001000] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [0.001000] CR2: ffff88007fe78070 CR3: 000000007da1d000 CR4: 00000000000006b0 > [0.001000] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [0.001000] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [0.001000] Call Trace: > [0.001000] virt_efi_set_variable+0x5d/0x70 > [0.001000] efi_delete_dummy_variable+0x7a/0x80 > [0.001000] efi_enter_virtual_mode+0x3f6/0x4a7 > [0.001000] start_kernel+0x375/0x400 > [0.001000] x86_64_start_reservations+0x2a/0x2c > [0.001000] x86_64_start_kernel+0x168/0x176 > [0.001000] start_cpu+0x14/0x14 > [0.001000] Code: 04 b0 84 ff 80 3d c5 56 b3 00 00 4c 8b 44 24 08 75 > 6b 9c 41 5e 48 8b 05 9c 78 99 00 4d 89 c1 48 89 de 4d 89 f8 44 89 e9 4c > 89 e2 <48> 8b 40 58 48 8b 78 58 e8 b0 2d 88 ff 48 c7 c6 b6 1d f4 81 4c > [0.001000] RIP: virt_efi_set_variable.part.7+0x63/0x1b0 RSP: ffffffff82003dc0 > [0.001000] CR2: ffff88007fe78070 > [0.001000] ---[ end trace 0000000000000000 ]--- > [0.001000] Kernel panic - not syncing: Attempted to kill the idle task! > [0.001000] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! > > [efi=old_map was never intended to work with kexec. The problem with > using efi=old_map is that the virtual addresses are assigned from the > memory region used by other kernel mappings; vmalloc() space. > Potentially there could be collisions when booting kexec if something > else is mapped at the virtual address we allocated for runtime service > regions in the initial boot] - Matt Fleming > > Since kexec was never intended to work with efi=old_map, disable > runtime services in kexec if booted with efi=old_map, so that we don't > panic. > > Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > Cc: Borislav Petkov <bp-Gina5bIWoIWzQB+pC5nmwQ@public.gmane.org> > Cc: Ricardo Neri <ricardo.neri-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > Cc: Matt Fleming <matt-mF/unelCI9GS6iBeEJttW/XRex20P6io@public.gmane.org> > Cc: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> > Cc: Ravi Shankar <ravi.v.shankar-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> > Cc: Lee Chun-Yi <jlee-IBi9RG/b67k@public.gmane.org> > Cc: Dave Young <dyoung-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> > > Changes since v1: > Don't fix the panic, because this was never intended to work. > --- > arch/x86/platform/efi/efi.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) Thanks Sai, applied to the urgent branch. ^ permalink raw reply [flat|nested] 5+ messages in thread
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2017-05-17 1:14 [PATCH v2] x86/efi: Disable runtime services on kexec kernel if booted with efi=old_map Sai Praneeth Prakhya
[not found] ` <1494983663-29286-1-git-send-email-sai.praneeth.prakhya-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
2017-05-17 1:57 ` Dave Young
[not found] ` <20170517015740.GA9562-0VdLhd/A9Pl+NNSt+8eSiB/sF2h8X+2i0E9HWUfgJXw@public.gmane.org>
2017-05-17 1:59 ` Sai Praneeth Prakhya
2017-05-17 7:29 ` joeyli
2017-05-25 11:58 ` Matt Fleming
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