already defines get_user() to __get_user(), with
__get_user() having an access_ok().
It would be really nice to have the same behavior and shared code across
all the arches.
--
Josh
*/
#endif
ASM_BARRIER_NOSPEC
11:
.endm
/* .. and the same for __get_user, just without the range checks */
SYM_FUNC_START(__get_user_nocheck_1)
__get_user_nocheck_nospec
ASM_STAC
UACCESS movzbl (%_ASM_AX),%edx
xor %eax,%eax
ASM_CLAC
RET
SYM_FUNC_END(__get_user_nocheck_1)
EXPORT_SYMBOL(__get_user_nocheck_1)
--
Josh
> On Fri, 15 Nov 2024 at 15:06, Josh Poimboeuf wrote:
> So I think the thing to do is
>
> (a) find out which __get_user() it is that matters so much for that load
>
> Do you have a profile somewhere?
>
> (b) convert them to use "unsafe_get_user()", with
On Fri, Nov 08, 2024 at 05:12:53PM +, David Laight wrote:
> From: Josh Poimboeuf
> > On Mon, Oct 28, 2024 at 06:56:15PM -0700, Josh Poimboeuf wrote:
> > > The barrier_nospec() in 64-bit __get_user() is slow. Instead use
> > > pointer masking to force the user point
it makes sense to hook into that existing
can_do_masked_user_access() thing. The patch looks good, and it boots
without blowing up. Thanks!
Reviewed-by: Josh Poimboeuf
--
Josh
On Mon, Oct 28, 2024 at 06:56:15PM -0700, Josh Poimboeuf wrote:
> The barrier_nospec() in 64-bit __get_user() is slow. Instead use
> pointer masking to force the user pointer to all 1's if a previous
> access_ok() mispredicted true for an invalid address.
Linus pointed out that __
user() and converge code.
Josh Poimboeuf (6):
x86/uaccess: Avoid barrier_nospec() in 64-bit copy_from_user()
x86/uaccess: Avoid barrier_nospec() in 64-bit __get_user()
x86/uaccess: Avoid barrier_nospec() in 32-bit copy_from_user()
x86/uaccess: Convert 32-bit get_user() to unconditional pointer
cal speculation
issue").
Link: https://lore.kernel.org/202410281344.d02c72a2-oliver.s...@intel.com
Signed-off-by: Josh Poimboeuf
---
arch/powerpc/include/asm/uaccess.h | 2 ++
arch/x86/include/asm/uaccess_32.h | 1 +
arch/x86/include/asm/uaccess_64.h | 1 +
include/linux/uaccess.h
Convert the 32-bit get_user() implementations to use the new
unconditional masking scheme for consistency with 64-bit.
Signed-off-by: Josh Poimboeuf
---
arch/x86/lib/getuser.S | 33 ++---
1 file changed, 14 insertions(+), 19 deletions(-)
diff --git a/arch/x86/lib
er address masking non-canonical speculation
issue").
Signed-off-by: Josh Poimboeuf
---
arch/x86/lib/getuser.S | 24
1 file changed, 20 insertions(+), 4 deletions(-)
diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S
index 4357ec2a0bfc..998d5be6b794 100644
---
The x86 implementations of get_user() and __get_user() are now
identical. Merge their implementations and make the __get_user()
implementations aliases of their get_user() counterparts.
Signed-off-by: Josh Poimboeuf
---
arch/x86/lib/getuser.S | 58 +-
1
The barrier_nospec() in 34-bit __get_user() is slow. Instead use
pointer masking to force the user pointer to all 1's if the access_ok()
mispredicted true for an invalid address.
Signed-off-by: Josh Poimboeuf
---
arch/x86/lib/getuser.S | 18 --
1 file changed, 18 dele
The barrier_nospec() in 32-bit copy_from_user() is slow. Instead use
pointer masking to force the user pointer to all 1's if a previous
access_ok() mispredicted true for an invalid address.
Signed-off-by: Josh Poimboeuf
---
arch/x86/include/asm/uaccess.h
On Sun, Oct 20, 2024 at 04:11:25PM -0700, Josh Poimboeuf wrote:
> #define FORCE_CANONICAL
> \
> ALTERNATIVE_2
> \
> "
On Sun, Oct 20, 2024 at 03:59:25PM -0700, Linus Torvalds wrote:
> On Sun, 20 Oct 2024 at 15:44, Josh Poimboeuf wrote:
> >
> > Anyway, I'd really like to make forward progress on getting rid of the
> > LFENCEs in copy_from_user() and __get_user(), so until if/when
On Mon, Oct 14, 2024 at 04:39:26PM +0100, Andrew Cooper wrote:
> On 14/10/2024 1:30 pm, Kirill A. Shutemov wrote:
> > +++ b/arch/x86/lib/getuser.S
> > @@ -37,9 +37,14 @@
> > +#define SHIFT_LEFT_TO_MSB ALTERNATIVE \
> > + "shl $(64 - 48), %rdx", \
> > + "shl $(64 - 57), %rdx", X86_FEATURE_LA57
>
On Fri, Oct 18, 2024 at 11:51:06AM +0300, Kirill A . Shutemov wrote:
> On Thu, Oct 17, 2024 at 02:55:22PM -0700, Josh Poimboeuf wrote:
> > SYM_FUNC_START(__put_user_2)
> > check_range size=2
> > ASM_STAC
> > -3: movw %ax,(%_ASM_CX)
> > +2: movw %ax
Add user pointer masking to clear_user() to mitigate Spectre v1.
A write in a mispredicted access_ok() branch to a user-controlled kernel
address can populate the rest of the affected cache line with kernel
data.
Signed-off-by: Josh Poimboeuf
---
arch/x86/include/asm/uaccess_64.h | 2 +-
1
: Josh Poimboeuf
---
arch/x86/lib/getuser.S | 25 +
1 file changed, 21 insertions(+), 4 deletions(-)
diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S
index 094224ec9dca..7c9bf8f0b3ac 100644
--- a/arch/x86/lib/getuser.S
+++ b/arch/x86/lib/getuser.S
@@ -105,6
Add user pointer masking to copy_to_user() to mitigate Spectre v1.
A write in a mispredicted access_ok() branch to a user-controlled kernel
address can populate the rest of the affected cache line with kernel
data.
Signed-off-by: Josh Poimboeuf
---
arch/x86/include/asm/uaccess_64.h | 1 +
1
Separate __put_user_*() from __put_user_nocheck_*() to make the layout
similar to getuser.S. This will also make it easier to do a subsequent
change. No functional changes.
Signed-off-by: Josh Poimboeuf
---
arch/x86/lib/putuser.S | 67 ++
1 file changed
.
Signed-off-by: Josh Poimboeuf
---
arch/x86/lib/putuser.S | 27 ++-
1 file changed, 22 insertions(+), 5 deletions(-)
diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S
index cb137e0286be..1b122261b7aa 100644
--- a/arch/x86/lib/putuser.S
+++ b/arch/x86/lib
__put_user()
v1:
https://lore.kernel.org/b626840e55d4aa86b4b9b377a4cc2cda7038d33d.1728706156.git.jpoim...@kernel.org
Josh Poimboeuf (6):
x86/uaccess: Avoid barrier_nospec() in copy_from_user()
x86/uaccess: Avoid barrier_nospec() in __get_user()
x86/uaccess: Rearrange putuser.S
x86/uaccess
there's no functional change.
Signed-off-by: Josh Poimboeuf
---
arch/powerpc/include/asm/uaccess.h | 2 ++
arch/x86/include/asm/uaccess_64.h | 7 ---
arch/x86/lib/getuser.S | 2 +-
arch/x86/lib/putuser.S | 2 +-
include/linux/uaccess.h| 6 --
5
On Sat, Oct 12, 2024 at 06:21:12PM -0700, Linus Torvalds wrote:
> On Sat, 12 Oct 2024 at 17:53, Linus Torvalds
> wrote:
> >
> > So no, the address masking can not depend on things like
> > __VIRTUAL_MASK_SHIFT, it would need to at least take LAM into account
> > too. Not that I know if there are a
On Sat, Oct 12, 2024 at 09:48:57AM +0100, Andrew Cooper wrote:
> On 12/10/2024 5:09 am, Josh Poimboeuf wrote:
> > For x86-64, the barrier_nospec() in copy_from_user() is overkill and
> > painfully slow. Instead, use pointer masking to force the user pointer
> > to a non
mispredicted access_ok() branch to a
user-controlled kernel address can populate the rest of the affected
cache line with kernel data.
To avoid regressing powerpc, move the barrier_nospec() to the powerpc
raw_copy_from_user() implementation so there's no functional change.
Signed-off-by: Josh Poim
bjtool should be able to do that reasonably easily, it already
> does it for checking section where userspace address access is enabled
> or not, which is very similar.
Yeah, that might be doable. I can look into it.
--
Josh
> > with modified stack frame
> >
>
> I can't really see any link between that warning and the changes in the
> patch.
I suspect it's a pre-existing warning, but because the patch made a
change to the default formatting (adding .text+off), it looks like a new
warning to the bots.
--
Josh
t more used to it. But the
scripts make it fine.
Also it helps with identifying the same warning across different
configs/compilers.
--
Josh
-0-46a69b507...@google.com
> (sorry for the spam with v2, mrincon is helping me get kinks worked out
> with b4 and our corporate mailer)
Acked-by: Josh Poimboeuf
--
Josh
On Thu, Feb 16, 2023 at 10:42:52AM -0800, Josh Poimboeuf wrote:
> Include to make sure play_dead() matches its prototype going
> forward.
>
> Acked-by: Florian Fainelli
> Reviewed-by: Philippe Mathieu-Daudé
> Signed-off-by: Josh Poimboeuf
The latest version of this pat
symbol with the
> SYM_FUNC_START_LOCAL and SYM_FUNC_END macros.
>
> Reported-by: Stephen Rothwell
> Signed-off-by: Sathvika Vasireddy
Suggested-by: Josh Poimboeuf
--
Josh
On Fri, Feb 17, 2023 at 12:35:17PM +1100, Michael Ellerman wrote:
> Josh Poimboeuf writes:
> > On Thu, Feb 16, 2023 at 02:40:31PM +1100, Stephen Rothwell wrote:
> >> Hi all,
> >>
> >> After merging the powerpc tree, today's linux-next build (powerpc
Include to make sure play_dead() matches its prototype going
forward.
Acked-by: Florian Fainelli
Reviewed-by: Philippe Mathieu-Daudé
Signed-off-by: Josh Poimboeuf
---
arch/mips/cavium-octeon/smp.c | 1 +
arch/mips/kernel/smp-bmips.c | 1 +
arch/mips/kernel/smp-cps.c| 1 +
arch/mips
cpu_die() doesn't return. Annotate it as such. By extension this also
makes arch_cpu_idle_dead() noreturn.
Acked-by: Mark Rutland
Signed-off-by: Josh Poimboeuf
---
arch/arm64/include/asm/smp.h | 2 +-
arch/arm64/kernel/smp.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
arch_cpu_idle_dead() doesn't return. Make that visible to the compiler
with an unreachable() code annotation.
Signed-off-by: Josh Poimboeuf
---
arch/arm/kernel/smp.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 0b8c257
On Thu, Feb 16, 2023 at 02:40:31PM +1100, Stephen Rothwell wrote:
> Hi all,
>
> After merging the powerpc tree, today's linux-next build (powerpc
> pseries_le_defconfig) produced this warning:
>
> arch/powerpc/kernel/head_64.o: warning: objtool: .text+0x6128: unannotated
> intra-function call
>
On Wed, Feb 15, 2023 at 01:09:21PM +, Mark Rutland wrote:
> On Tue, Feb 14, 2023 at 09:13:08AM +0100, Philippe Mathieu-Daudé wrote:
> > On 14/2/23 08:05, Josh Poimboeuf wrote:
> > > cpu_die() doesn't return. Annotate it as such. By extension this also
> &g
On Tue, Feb 14, 2023 at 11:48:41AM -0800, Max Filippov wrote:
> On Tue, Feb 14, 2023 at 10:23 AM Josh Poimboeuf wrote:
> > On Tue, Feb 14, 2023 at 08:55:32AM +0100, Philippe Mathieu-Daudé wrote:
> > > Can you update the documentation along? Currently we have:
> > >
&
On Tue, Feb 14, 2023 at 11:15:23AM +, Russell King (Oracle) wrote:
> On Mon, Feb 13, 2023 at 11:05:37PM -0800, Josh Poimboeuf wrote:
> > arch_cpu_idle_dead() doesn't return. Make that more explicit with a
> > BUG().
> >
> > BUG() is preferable to unrea
On Tue, Feb 14, 2023 at 10:25:50AM +0100, Philippe Mathieu-Daudé wrote:
> On 14/2/23 08:05, Josh Poimboeuf wrote:
> > v2:
> > - make arch_call_rest_init() and rest_init() __noreturn
> > - make objtool 'global_returns' work for weak functions
> > - rebase
On Tue, Feb 14, 2023 at 08:57:39AM +0100, Philippe Mathieu-Daudé wrote:
> On 14/2/23 08:05, Josh Poimboeuf wrote:
> > play_dead() doesn't return. Make that more explicit with a BUG().
> >
> > BUG() is preferable to unreachable() because BUG() is a more explicit
&
On Tue, Feb 14, 2023 at 08:55:32AM +0100, Philippe Mathieu-Daudé wrote:
> Hi Josh,
>
> On 14/2/23 08:05, Josh Poimboeuf wrote:
> > cpu_die() doesn't return. Make that more explicit with a BUG().
> >
> > BUG() is preferable to unreachable() because BUG() is a mo
On Tue, Feb 14, 2023 at 08:46:41AM +0100, Philippe Mathieu-Daudé wrote:
> Hi Josh,
>
> On 14/2/23 08:05, Josh Poimboeuf wrote:
> > Include to make sure play_dead() matches its prototype going
> > forward.
> >
> > Acked-by: Florian Fainelli
> > Signed-off
plain if an arch-specific
implementation might return. It also improves code generation for both
caller and callee.
Also fixes the following warning:
vmlinux.o: warning: objtool: do_idle+0x25f: unreachable instruction
Reported-by: Paul E. McKenney
Tested-by: Paul E. McKenney
Signed-off-by:
arch_call_rest_init() and rest_init() don't return. Annotate them as
such.
Fixes the following warning:
init/main.o: warning: objtool: start_kernel+0x4ad: unreachable instruction
Signed-off-by: Josh Poimboeuf
---
arch/s390/kernel/setup.c | 2 +-
include/linux/start_kernel.
If a global __noreturn function prototype has a corresponding weak
function, it should also be __noreturn.
Signed-off-by: Josh Poimboeuf
---
tools/objtool/check.c | 8
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index
arch_cpu_idle_dead() should never return. Make it so.
Signed-off-by: Josh Poimboeuf
---
kernel/sched/idle.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index e9ef66be2870..56e152f06d0f 100644
--- a/kernel/sched/idle.c
+++ b
cpu_die() doesn't return. Annotate it as such. By extension this also
makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/xtensa/include/asm/smp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/xtensa/include/asm/smp.h b/arch/xtensa/in
cpu_die() doesn't return. Make that more explicit with a BUG().
BUG() is preferable to unreachable() because BUG() is a more explicit
failure mode and avoids undefined behavior like falling off the edge of
the function into whatever code happens to be next.
Signed-off-by: Josh Poim
play_dead() doesn't return. Annotate it as such. By extension this
also makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/x86/include/asm/smp.h | 2 +-
arch/x86/kernel/process.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/in
of
the function into whatever code happens to be next.
Signed-off-by: Josh Poimboeuf
---
arch/x86/include/asm/smp.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index b4dbb20dab1a..8f628e08b25a 100644
--- a/arch/x86/include/asm/smp.h
cpu_play_dead() doesn't return. Annotate it as such. By extension this
also makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/sparc/include/asm/smp_64.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/sparc/include/asm/smp_64.h b/arch/
Include to make sure arch_cpu_idle_dead() matches its
prototype going forward.
Signed-off-by: Josh Poimboeuf
---
arch/sh/kernel/idle.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/sh/kernel/idle.c b/arch/sh/kernel/idle.c
index 3418c40f0099..114f0c4abeac 100644
--- a/arch/sh/kernel
play_dead() doesn't return. Annotate it as such. By extension this
also makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/sh/include/asm/smp-ops.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/sh/include/asm/smp-ops.h b/arch/sh/in
play_dead() doesn't return. Make that more explicit with a BUG().
BUG() is preferable to unreachable() because BUG() is a more explicit
failure mode and avoids undefined behavior like falling off the edge of
the function into whatever code happens to be next.
Signed-off-by: Josh Poim
start_secondary_resume() doesn't return. Annotate it as such. By
extension this also makes arch_cpu_idle_dead() noreturn.
Acked-by: Michael Ellerman (powerpc)
Signed-off-by: Josh Poimboeuf
---
arch/powerpc/include/asm/smp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --
play_dead() doesn't return. Annotate it as such. By extension this
also makes arch_cpu_idle_dead() noreturn.
Acked-by: Florian Fainelli
Signed-off-by: Josh Poimboeuf
---
arch/mips/include/asm/smp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/mips/includ
igned-off-by: Josh Poimboeuf
---
arch/mips/kernel/smp-bmips.c | 2 ++
arch/mips/loongson64/smp.c | 1 +
2 files changed, 3 insertions(+)
diff --git a/arch/mips/kernel/smp-bmips.c b/arch/mips/kernel/smp-bmips.c
index df9158e8329d..be85fa075830 100644
--- a/arch/mips/kernel/smp-bmips.c
+++ b/arch
Include to make sure play_dead() matches its prototype going
forward.
Acked-by: Florian Fainelli
Signed-off-by: Josh Poimboeuf
---
arch/mips/kernel/smp-bmips.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/mips/kernel/smp-bmips.c b/arch/mips/kernel/smp-bmips.c
index f5d7bfa3472a
play_dead() doesn't return. Annotate it as such. By extension this
also makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/loongarch/include/asm/smp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/loongarch/include/asm/smp.h b/arch/loon
play_dead() doesn't return. Make that more explicit with a BUG().
BUG() is preferable to unreachable() because BUG() is a more explicit
failure mode and avoids undefined behavior like falling off the edge of
the function into whatever code happens to be next.
Signed-off-by: Josh Poim
play_dead() doesn't return. Annotate it as such. By extension this
also makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/ia64/kernel/process.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/k
igned-off-by: Josh Poimboeuf
---
arch/csky/kernel/smp.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/csky/kernel/smp.c b/arch/csky/kernel/smp.c
index b45d1073307f..0ec20efaf5fd 100644
--- a/arch/csky/kernel/smp.c
+++ b/arch/csky/kernel/smp.c
@@ -317,5 +317,7 @@ void arch_cpu_idle_dead
cpu_die() doesn't return. Annotate it as such. By extension this also
makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/arm64/include/asm/smp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/includ
arch_cpu_idle_dead() doesn't return. Make that more explicit with a
BUG().
BUG() is preferable to unreachable() because BUG() is a more explicit
failure mode and avoids undefined behavior like falling off the edge of
the function into whatever code happens to be next.
Signed-off-by:
Include to make sure arch_cpu_idle_dead() matches its
prototype going forward.
Signed-off-by: Josh Poimboeuf
---
arch/alpha/kernel/process.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index ce20c31828a0..d1f2e8b6b107 100644
arch_cpu_idle_dead() doesn't return. Make that more explicit with a
BUG().
BUG() is preferable to unreachable() because BUG() is a more explicit
failure mode and avoids undefined behavior like falling off the edge of
the function into whatever code happens to be next.
Signed-off-by:
v2:
- make arch_call_rest_init() and rest_init() __noreturn
- make objtool 'global_returns' work for weak functions
- rebase on tip/objtool/core with dependencies merged in (mingo)
- add acks
v1.1:
- add __noreturn to all arch_cpu_idle_dead() implementations (mpe)
Josh Poimboeuf (24
plain if an arch-specific
implementation might return. It also improves code generation for both
caller and callee.
Also fixes the following warning:
vmlinux.o: warning: objtool: do_idle+0x25f: unreachable instruction
Reported-by: Paul E. McKenney
Tested-by: Paul E. McKenney
Signed-off-by:
On Mon, Feb 06, 2023 at 10:10:22PM +1100, Michael Ellerman wrote:
> Josh Poimboeuf writes:
> > start_secondary_resume() doesn't return. Annotate it as such. By
> > extension this also makes arch_cpu_idle_dead() noreturn.
>
> Can we also mark arch_cpu_idle_dead() (
On Sun, Feb 05, 2023 at 11:46:12AM +1100, Michael Ellerman wrote:
> Josh Poimboeuf writes:
> > On Tue, Jan 24, 2023 at 07:38:03PM -0800, Josh Poimboeuf wrote:
> >> Fix a livepatch bug seen when reloading a patched module.
> >>
> >> This is the powerpc counter
On Tue, Jan 24, 2023 at 07:38:03PM -0800, Josh Poimboeuf wrote:
> Fix a livepatch bug seen when reloading a patched module.
>
> This is the powerpc counterpart to Song Liu's fix for a similar issue on
> x86:
>
> https://lkml.kernel.org/lkml/20230121004945.697003-2-s.
On Sat, Feb 04, 2023 at 02:10:34PM +0100, Christophe Leroy wrote:
> Ok, got the same problem as you with next-20230203
>
> DESCEND objtool
> :1:10: fatal error: libelf.h: No such file or directory
> compilation terminated.
> HOSTCC /home/chleroy/linux-powerpc/tools/objtool/fixdep.o
> HOSTLD
On Sat, Feb 04, 2023 at 09:12:31AM +0800, Guo Ren wrote:
> On Sat, Feb 4, 2023 at 6:05 AM Josh Poimboeuf wrote:
> >
> > arch_cpu_idle_dead() doesn't return. Make that more explicit with a
> > BUG().
> >
> > BUG() is preferable to unreachable() because BUG
plain if an arch-specific
implementation might return. It also improves code generation for both
caller and callee.
Also fixes the following warning:
vmlinux.o: warning: objtool: do_idle+0x25f: unreachable instruction
Reported-by: Paul E. McKenney
Tested-by: Paul E. McKenney
Sign
arch_cpu_idle_dead() should never return. Make it so.
Signed-off-by: Josh Poimboeuf
---
kernel/sched/idle.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index e9ef66be2870..56e152f06d0f 100644
--- a/kernel/sched/idle.c
+++ b
cpu_die() doesn't return. Annotate it as such. By extension this also
makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/xtensa/include/asm/smp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/xtensa/include/asm/smp.h b/arch/xtensa/in
play_dead() doesn't return. Annotate it as such. By extension this
also makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/x86/include/asm/smp.h | 2 +-
arch/x86/kernel/process.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/in
cpu_die() doesn't return. Make that more explicit with a BUG().
BUG() is preferable to unreachable() because BUG() is a more explicit
failure mode and avoids undefined behavior like falling off the edge of
the function into whatever code happens to be next.
Signed-off-by: Josh Poim
of
the function into whatever code happens to be next.
Signed-off-by: Josh Poimboeuf
---
arch/x86/include/asm/smp.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index b4dbb20dab1a..8f628e08b25a 100644
--- a/arch/x86/include/asm/smp.h
Include to make sure arch_cpu_idle_dead() matches its
prototype going forward.
Signed-off-by: Josh Poimboeuf
---
arch/sh/kernel/idle.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/sh/kernel/idle.c b/arch/sh/kernel/idle.c
index 3418c40f0099..114f0c4abeac 100644
--- a/arch/sh/kernel
cpu_play_dead() doesn't return. Annotate it as such. By extension this
also makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/sparc/include/asm/smp_64.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/sparc/include/asm/smp_64.h b/arch/
play_dead() doesn't return. Make that more explicit with a BUG().
BUG() is preferable to unreachable() because BUG() is a more explicit
failure mode and avoids undefined behavior like falling off the edge of
the function into whatever code happens to be next.
Signed-off-by: Josh Poim
play_dead() doesn't return. Annotate it as such. By extension this
also makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/sh/include/asm/smp-ops.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/sh/include/asm/smp-ops.h b/arch/sh/in
start_secondary_resume() doesn't return. Annotate it as such. By
extension this also makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/powerpc/include/asm/smp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/smp.h b
play_dead() doesn't return. Make that more explicit with a BUG().
BUG() is preferable to unreachable() because BUG() is a more explicit
failure mode and avoids undefined behavior like falling off the edge of
the function into whatever code happens to be next.
Signed-off-by: Josh Poim
play_dead() doesn't return. Annotate it as such. By extension this
also makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/mips/include/asm/smp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/mips/include/asm/smp.h b/arch/mips/includ
Include to make sure play_dead() matches its prototype going
forward.
Signed-off-by: Josh Poimboeuf
---
arch/mips/kernel/smp-bmips.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/mips/kernel/smp-bmips.c b/arch/mips/kernel/smp-bmips.c
index f5d7bfa3472a..df9158e8329d 100644
--- a
play_dead() doesn't return. Annotate it as such. By extension this
also makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/loongarch/include/asm/smp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/loongarch/include/asm/smp.h b/arch/loon
play_dead() doesn't return. Make that more explicit with a BUG().
BUG() is preferable to unreachable() because BUG() is a more explicit
failure mode and avoids undefined behavior like falling off the edge of
the function into whatever code happens to be next.
Signed-off-by: Josh Poim
play_dead() doesn't return. Annotate it as such. By extension this
also makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/ia64/kernel/process.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/ia64/kernel/process.c b/arch/ia64/k
arch_cpu_idle_dead() doesn't return. Make that more explicit with a
BUG().
BUG() is preferable to unreachable() because BUG() is a more explicit
failure mode and avoids undefined behavior like falling off the edge of
the function into whatever code happens to be next.
Signed-off-by:
cpu_die() doesn't return. Annotate it as such. By extension this also
makes arch_cpu_idle_dead() noreturn.
Signed-off-by: Josh Poimboeuf
---
arch/arm64/include/asm/smp.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/includ
arch_cpu_idle_dead() doesn't return. Make that more explicit with a
BUG().
BUG() is preferable to unreachable() because BUG() is a more explicit
failure mode and avoids undefined behavior like falling off the edge of
the function into whatever code happens to be next.
Signed-off-by:
attribute.
[1] 076cbf5d2163 ("x86/xen: don't let xen_pv_play_dead() return")
Josh Poimboeuf (22):
alpha/cpu: Expose arch_cpu_idle_dead()'s prototype declaration
alpha/cpu: Make sure arch_cpu_idle_dead() doesn't return
arm/cpu: Make sure arch_cpu_idle_dead()
arch_cpu_idle_dead() doesn't return. Make that more explicit with a
BUG().
BUG() is preferable to unreachable() because BUG() is a more explicit
failure mode and avoids undefined behavior like falling off the edge of
the function into whatever code happens to be next.
Signed-off-by:
Include to make sure arch_cpu_idle_dead() matches its
prototype going forward.
Signed-off-by: Josh Poimboeuf
---
arch/alpha/kernel/process.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index 0eddd22c6212..4813172547b5 100644
On Wed, Jan 25, 2023 at 09:36:02AM -0800, Song Liu wrote:
> On Wed, Jan 25, 2023 at 8:46 AM Josh Poimboeuf wrote:
> >
> > On Tue, Jan 24, 2023 at 10:09:56PM -0800, Song Liu wrote:
> > > > @@ -514,9 +515,18 @@ static int restore_r2(const char *name, u32
> > &g
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