arch/x86/platform/efi/efi_64.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)
The following commit has been merged into the x86/alternatives branch of tip:
Commit-ID: e7021e2fe0b4335523d3f6e2221000bdfc633b62
Gitweb: https://git.kernel.org/tip/e7021e2fe0b4335523d3f6e2221000bdfc633b62
Author: Andy Lutomirski <luto@kernel.org>
AuthorDate: Wed, 02 Apr 2025 11:45:39 +02:00
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Sat, 12 Apr 2025 10:06:04 +02:00
x86/efi: Make efi_enter/leave_mm() use the use_/unuse_temporary_mm() machinery
This should be considerably more robust. It's also necessary for optimized
for_each_possible_lazymm_cpu() on x86 -- without this patch, EFI calls in
lazy context would remove the lazy mm from mm_cpumask().
[ mingo: Merged it on top of x86/alternatives ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/r/20250402094540.3586683-7-mingo@kernel.org
---
arch/x86/platform/efi/efi_64.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index ac57259..a5d3496 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -434,15 +434,12 @@ void __init efi_dump_pagetable(void)
*/
static void efi_enter_mm(void)
{
- efi_prev_mm = current->active_mm;
- current->active_mm = &efi_mm;
- switch_mm(efi_prev_mm, &efi_mm, NULL);
+ efi_prev_mm = use_temporary_mm(&efi_mm);
}
static void efi_leave_mm(void)
{
- current->active_mm = efi_prev_mm;
- switch_mm(&efi_mm, efi_prev_mm, NULL);
+ unuse_temporary_mm(efi_prev_mm);
}
void arch_efi_call_virt_setup(void)On Sat, Apr 12, 2025 at 06:46:48PM -0000, tip-bot2 for Andy Lutomirski wrote:
> The following commit has been merged into the x86/alternatives branch of tip:
>
> Commit-ID: e7021e2fe0b4335523d3f6e2221000bdfc633b62
> Gitweb: https://git.kernel.org/tip/e7021e2fe0b4335523d3f6e2221000bdfc633b62
> Author: Andy Lutomirski <luto@kernel.org>
> AuthorDate: Wed, 02 Apr 2025 11:45:39 +02:00
> Committer: Ingo Molnar <mingo@kernel.org>
> CommitterDate: Sat, 12 Apr 2025 10:06:04 +02:00
>
> x86/efi: Make efi_enter/leave_mm() use the use_/unuse_temporary_mm() machinery
>
> This should be considerably more robust. It's also necessary for optimized
> for_each_possible_lazymm_cpu() on x86 -- without this patch, EFI calls in
> lazy context would remove the lazy mm from mm_cpumask().
>
> [ mingo: Merged it on top of x86/alternatives ]
>
> Signed-off-by: Andy Lutomirski <luto@kernel.org>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Signed-off-by: Ingo Molnar <mingo@kernel.org>
> Cc: Rik van Riel <riel@surriel.com>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Link: https://lore.kernel.org/r/20250402094540.3586683-7-mingo@kernel.org
> ---
> arch/x86/platform/efi/efi_64.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
> index ac57259..a5d3496 100644
> --- a/arch/x86/platform/efi/efi_64.c
> +++ b/arch/x86/platform/efi/efi_64.c
> @@ -434,15 +434,12 @@ void __init efi_dump_pagetable(void)
> */
> static void efi_enter_mm(void)
> {
> - efi_prev_mm = current->active_mm;
> - current->active_mm = &efi_mm;
> - switch_mm(efi_prev_mm, &efi_mm, NULL);
> + efi_prev_mm = use_temporary_mm(&efi_mm);
> }
>
> static void efi_leave_mm(void)
> {
> - current->active_mm = efi_prev_mm;
> - switch_mm(&efi_mm, efi_prev_mm, NULL);
> + unuse_temporary_mm(efi_prev_mm);
> }
>
> void arch_efi_call_virt_setup(void)
mingo thinks this one causes this:
[ 0.119491] x86/fpu: xstate_offset[2]: 576, xstate_sizes[2]: 256
[ 0.119498] x86/fpu: Enabled xstate features 0x7, context size is 832 bytes, using 'compacted' format.
[ 0.137368] Freeing SMP alternatives memory: 40K
[ 0.137381] pid_max: default: 32768 minimum: 301
[ 0.137496] ------------[ cut here ]------------
[ 0.137502] WARNING: CPU: 0 PID: 0 at arch/x86/mm/tlb.c:795 switch_mm_irqs_off+0x3d3/0x460
[ 0.137516] Modules linked in:
[ 0.137526] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-rc2+ #3 PREEMPT(voluntary)
[ 0.137537] Hardware name: HP HP ProBook 635 Aero G7 Notebook PC/8830, BIOS S84 Ver. 01.05.00 05/14/2021
[ 0.137548] RIP: 0010:switch_mm_irqs_off+0x3d3/0x460
[ 0.137556] Code: 28 00 65 ff 0d 3e c9 db 01 0f 85 88 fd ff ff 0f 1f 44 00 00 e9 7e fd ff ff be 00 01 00 00 31 ff e8 02 cb fb ff e9 be fd ff ff <0f> 0b e9 6c fc ff ff 9c 58 f6 c4 02 0f 84 c4 fd ff ff e8 46 3b 59
[ 0.137575] RSP: 0000:ffffffffb6a03e00 EFLAGS: 00010202
[ 0.137583] RAX: 0000000000000246 RBX: ffffffffb6c5fd40 RCX: 0000000100238000
[ 0.137591] RDX: ffffffffb6a149c0 RSI: ffffffffb6c5fd40 RDI: 0000000000000000
[ 0.137599] RBP: ffffffffb6bbcdc0 R08: 00000000b357d000 R09: 0000000000000000
[ 0.137607] R10: 000000010ab06067 R11: 0000000000000000 R12: ffffffffb6a149c0
[ 0.137616] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[ 0.137624] FS: 0000000000000000(0000) GS:ffff9b6093385000(0000) knlGS:0000000000000000
[ 0.137633] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.137640] CR2: ffff9b6048601000 CR3: 0000000106c26000 CR4: 0000000000350ef0
[ 0.137648] Call Trace:
[ 0.137653] <TASK>
[ 0.137658] use_temporary_mm+0x55/0x90
[ 0.137666] efi_set_virtual_address_map+0xfd/0x1b0
[ 0.137676] efi_enter_virtual_mode+0x3e3/0x450
[ 0.137685] start_kernel+0x6b7/0x720
[ 0.137693] x86_64_start_reservations+0x24/0x30
[ 0.137700] x86_64_start_kernel+0x7a/0x80
[ 0.137706] common_startup_64+0x13e/0x141
[ 0.137717] </TASK>
[ 0.137720] irq event stamp: 128439
[ 0.137725] hardirqs last enabled at (128447): [<ffffffffb579dcd2>] __up_console_sem+0x52/0x60
[ 0.137737] hardirqs last disabled at (128454): [<ffffffffb579dcb7>] __up_console_sem+0x37/0x60
[ 0.137748] softirqs last enabled at (105766): [<ffffffffb56f57b6>] __irq_exit_rcu+0x96/0xc0
[ 0.137759] softirqs last disabled at (105759): [<ffffffffb56f57b6>] __irq_exit_rcu+0x96/0xc0
[ 0.137770] ---[ end trace 0000000000000000 ]---
[ 0.137777] ------------[ cut here ]------------
[ 0.137782] WARNING: CPU: 0 PID: 0 at arch/x86/kernel/cpu/common.c:453 cr4_update_irqsoff+0x45/0x70
[ 0.137794] Modules linked in:
[ 0.137800] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G W 6.15.0-rc2+ #3 PREEMPT(voluntary)
[ 0.137813] Tainted: [W]=WARN
[ 0.137817] Hardware name: HP HP ProBook 635 Aero G7 Notebook PC/8830, BIOS S84 Ver. 01.05.00 05/14/2021
[ 0.137827] RIP: 0010:cr4_update_irqsoff+0x45/0x70
[ 0.137834] Code: 0b 65 8b 0d d5 3d e0 01 85 c9 74 13 48 f7 d7 48 21 d7 48 09 c7 48 39 fa 75 20 e9 f6 8d b8 00 65 8b 0d 9b 3a e0 01 85 c9 74 e2 <0f> 0b 48 f7 d7 48 21 d7 48 09 c7 48 39 fa 74 e0 65 48 89 3d eb 6a
[ 0.137853] RSP: 0000:ffffffffb6a03df8 EFLAGS: 00010202
[ 0.137860] RAX: 0000000000000000 RBX: ffffffffb6c5fd40 RCX: 0000000000000001
[ 0.137868] RDX: 0000000000350ef0 RSI: 0000000000000100 RDI: 0000000000000100
[ 0.137876] RBP: ffffffffb6bbcdc0 R08: 00000000b357d000 R09: 0000000000000000
[ 0.137884] R10: 000000010ab06067 R11: 0000000000000000 R12: 000000010022e000
[ 0.137892] R13: 0000000000010000 R14: 0000000000000000 R15: 0000000000000000
[ 0.137900] FS: 0000000000000000(0000) GS:ffff9b6093385000(0000) knlGS:0000000000000000
[ 0.137909] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.137916] CR2: ffff9b6048601000 CR3: 000000010022e000 CR4: 0000000000350ef0
[ 0.137924] Call Trace:
[ 0.137928] <TASK>
[ 0.137932] switch_mm_irqs_off+0x3ce/0x460
[ 0.137940] use_temporary_mm+0x55/0x90
[ 0.137946] efi_set_virtual_address_map+0xfd/0x1b0
[ 0.137956] efi_enter_virtual_mode+0x3e3/0x450
[ 0.137964] start_kernel+0x6b7/0x720
[ 0.137971] x86_64_start_reservations+0x24/0x30
[ 0.137978] x86_64_start_kernel+0x7a/0x80
[ 0.137984] common_startup_64+0x13e/0x141
[ 0.137994] </TASK>
[ 0.137998] irq event stamp: 128723
[ 0.138002] hardirqs last enabled at (128731): [<ffffffffb579dcd2>] __up_console_sem+0x52/0x60
[ 0.138013] hardirqs last disabled at (128738): [<ffffffffb579dcb7>] __up_console_sem+0x37/0x60
[ 0.138024] softirqs last enabled at (105766): [<ffffffffb56f57b6>] __irq_exit_rcu+0x96/0xc0
[ 0.138034] softirqs last disabled at (105759): [<ffffffffb56f57b6>] __irq_exit_rcu+0x96/0xc0
[ 0.138045] ---[ end trace 0000000000000000 ]---
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
On Thu, Apr 17, 2025 at 04:17:51PM +0200, Borislav Petkov wrote:
> On Sat, Apr 12, 2025 at 06:46:48PM -0000, tip-bot2 for Andy Lutomirski wrote:
> > The following commit has been merged into the x86/alternatives branch of tip:
> >
> > Commit-ID: e7021e2fe0b4335523d3f6e2221000bdfc633b62
> > Gitweb: https://git.kernel.org/tip/e7021e2fe0b4335523d3f6e2221000bdfc633b62
> > Author: Andy Lutomirski <luto@kernel.org>
> > AuthorDate: Wed, 02 Apr 2025 11:45:39 +02:00
> > Committer: Ingo Molnar <mingo@kernel.org>
> > CommitterDate: Sat, 12 Apr 2025 10:06:04 +02:00
> >
> > x86/efi: Make efi_enter/leave_mm() use the use_/unuse_temporary_mm() machinery
> >
> > This should be considerably more robust. It's also necessary for optimized
> > for_each_possible_lazymm_cpu() on x86 -- without this patch, EFI calls in
> > lazy context would remove the lazy mm from mm_cpumask().
> >
> > [ mingo: Merged it on top of x86/alternatives ]
> >
> > Signed-off-by: Andy Lutomirski <luto@kernel.org>
> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > Signed-off-by: Ingo Molnar <mingo@kernel.org>
> > Cc: Rik van Riel <riel@surriel.com>
> > Cc: "H. Peter Anvin" <hpa@zytor.com>
> > Cc: Linus Torvalds <torvalds@linux-foundation.org>
> > Cc: Andrew Morton <akpm@linux-foundation.org>
> > Link: https://lore.kernel.org/r/20250402094540.3586683-7-mingo@kernel.org
> > ---
> > arch/x86/platform/efi/efi_64.c | 7 ++-----
> > 1 file changed, 2 insertions(+), 5 deletions(-)
> >
> > diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
> > index ac57259..a5d3496 100644
> > --- a/arch/x86/platform/efi/efi_64.c
> > +++ b/arch/x86/platform/efi/efi_64.c
> > @@ -434,15 +434,12 @@ void __init efi_dump_pagetable(void)
> > */
> > static void efi_enter_mm(void)
> > {
> > - efi_prev_mm = current->active_mm;
> > - current->active_mm = &efi_mm;
> > - switch_mm(efi_prev_mm, &efi_mm, NULL);
> > + efi_prev_mm = use_temporary_mm(&efi_mm);
> > }
> >
> > static void efi_leave_mm(void)
> > {
> > - current->active_mm = efi_prev_mm;
> > - switch_mm(&efi_mm, efi_prev_mm, NULL);
> > + unuse_temporary_mm(efi_prev_mm);
> > }
> >
> > void arch_efi_call_virt_setup(void)
>
> mingo thinks this one causes this:
>
> [ 0.119491] x86/fpu: xstate_offset[2]: 576, xstate_sizes[2]: 256
> [ 0.119498] x86/fpu: Enabled xstate features 0x7, context size is 832 bytes, using 'compacted' format.
> [ 0.137368] Freeing SMP alternatives memory: 40K
> [ 0.137381] pid_max: default: 32768 minimum: 301
> [ 0.137496] ------------[ cut here ]------------
> [ 0.137502] WARNING: CPU: 0 PID: 0 at arch/x86/mm/tlb.c:795 switch_mm_irqs_off+0x3d3/0x460
> [ 0.137516] Modules linked in:
Ah yes :-( Something like so perhaps..
---
Subject: x86/mm: Fix {,un}use_temporary_mm() IRQ state
As the function switch_mm_irqs_off() implies, it ought to be called with
IRQs *off*. Commit 58f8ffa91766 ("x86/mm: Allow temporary MMs when IRQs
are on") caused this to not be the case for EFI.
Ensure IRQs are off where it matters.
Fixes: 58f8ffa91766 ("x86/mm: Allow temporary MMs when IRQs are on")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 92bde0d6205a..1451e022129a 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -991,6 +991,7 @@ struct mm_struct *use_temporary_mm(struct mm_struct *temp_mm)
struct mm_struct *prev_mm;
lockdep_assert_preemption_disabled();
+ guard(irqsave)();
/*
* Make sure not to be in TLB lazy mode, as otherwise we'll end up
@@ -1023,6 +1024,7 @@ struct mm_struct *use_temporary_mm(struct mm_struct *temp_mm)
void unuse_temporary_mm(struct mm_struct *prev_mm)
{
lockdep_assert_preemption_disabled();
+ guard(irqsave)();
/* Clear the cpumask, to indicate no TLB flushing is needed anywhere */
cpumask_clear_cpu(smp_processor_id(), mm_cpumask(this_cpu_read(cpu_tlbstate.loaded_mm)));
On Fri, Apr 18, 2025 at 11:50:34AM +0200, Peter Zijlstra wrote:
> Ah yes :-( Something like so perhaps..
Thanks, that does it.
Reported-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Borislav Petkov (AMD) <bp@alien8.de>
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
* Borislav Petkov <bp@alien8.de> wrote: > On Fri, Apr 18, 2025 at 11:50:34AM +0200, Peter Zijlstra wrote: > > Ah yes :-( Something like so perhaps.. > > Thanks, that does it. > > Reported-by: Borislav Petkov (AMD) <bp@alien8.de> > Tested-by: Borislav Petkov (AMD) <bp@alien8.de> Applied to tip:x86/alternatives, thanks guys! Ingo
The following commit has been merged into the x86/alternatives branch of tip:
Commit-ID: aef1d0209ddf127a8069aca5fa3a062be4136b76
Gitweb: https://git.kernel.org/tip/aef1d0209ddf127a8069aca5fa3a062be4136b76
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Fri, 18 Apr 2025 11:50:34 +02:00
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Fri, 18 Apr 2025 14:36:18 +02:00
x86/mm: Fix {,un}use_temporary_mm() IRQ state
As the function switch_mm_irqs_off() implies, it ought to be called with
IRQs *off*. Commit 58f8ffa91766 ("x86/mm: Allow temporary MMs when IRQs
are on") caused this to not be the case for EFI.
Ensure IRQs are off where it matters.
Fixes: 58f8ffa91766 ("x86/mm: Allow temporary MMs when IRQs are on")
Reported-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rik van Riel <riel@surriel.com>
Link: https://lore.kernel.org/r/20250418095034.GR38216@noisy.programming.kicks-ass.net
---
arch/x86/mm/tlb.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 79c124f..39761c7 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -986,6 +986,7 @@ struct mm_struct *use_temporary_mm(struct mm_struct *temp_mm)
struct mm_struct *prev_mm;
lockdep_assert_preemption_disabled();
+ guard(irqsave)();
/*
* Make sure not to be in TLB lazy mode, as otherwise we'll end up
@@ -1018,6 +1019,7 @@ struct mm_struct *use_temporary_mm(struct mm_struct *temp_mm)
void unuse_temporary_mm(struct mm_struct *prev_mm)
{
lockdep_assert_preemption_disabled();
+ guard(irqsave)();
/* Clear the cpumask, to indicate no TLB flushing is needed anywhere */
cpumask_clear_cpu(smp_processor_id(), mm_cpumask(this_cpu_read(cpu_tlbstate.loaded_mm)));© 2016 - 2025 Red Hat, Inc.