<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch, branch v6.6.4</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>arm/xen: fix xen_vcpu_info allocation alignment</title>
<updated>2023-12-03T06:33:05+00:00</updated>
<author>
<name>Stefano Stabellini</name>
<email>sstabellini@kernel.org</email>
</author>
<published>2023-11-22T23:07:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3c1963b5e7b913a08aad348c55219bfd19654a96'/>
<id>3c1963b5e7b913a08aad348c55219bfd19654a96</id>
<content type='text'>
[ Upstream commit 7bf9a6b46549852a37e6d07e52c601c3c706b562 ]

xen_vcpu_info is a percpu area than needs to be mapped by Xen.
Currently, it could cross a page boundary resulting in Xen being unable
to map it:

[    0.567318] kernel BUG at arch/arm64/xen/../../arm/xen/enlighten.c:164!
[    0.574002] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP

Fix the issue by using __alloc_percpu and requesting alignment for the
memory allocation.

Signed-off-by: Stefano Stabellini &lt;stefano.stabellini@amd.com&gt;

Link: https://lore.kernel.org/r/alpine.DEB.2.22.394.2311221501340.2053963@ubuntu-linux-20-04-desktop
Fixes: 24d5373dda7c ("arm/xen: Use alloc_percpu rather than __alloc_percpu")
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 7bf9a6b46549852a37e6d07e52c601c3c706b562 ]

xen_vcpu_info is a percpu area than needs to be mapped by Xen.
Currently, it could cross a page boundary resulting in Xen being unable
to map it:

[    0.567318] kernel BUG at arch/arm64/xen/../../arm/xen/enlighten.c:164!
[    0.574002] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP

Fix the issue by using __alloc_percpu and requesting alignment for the
memory allocation.

Signed-off-by: Stefano Stabellini &lt;stefano.stabellini@amd.com&gt;

Link: https://lore.kernel.org/r/alpine.DEB.2.22.394.2311221501340.2053963@ubuntu-linux-20-04-desktop
Fixes: 24d5373dda7c ("arm/xen: Use alloc_percpu rather than __alloc_percpu")
Reviewed-by: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: Juergen Gross &lt;jgross@suse.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: mm: Fix "rodata=on" when CONFIG_RODATA_FULL_DEFAULT_ENABLED=y</title>
<updated>2023-12-03T06:33:05+00:00</updated>
<author>
<name>Will Deacon</name>
<email>will@kernel.org</email>
</author>
<published>2023-11-17T13:14:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1bf36832f878260b1f5bf1b1405a7b7c57de4daf'/>
<id>1bf36832f878260b1f5bf1b1405a7b7c57de4daf</id>
<content type='text'>
[ Upstream commit acfa60dbe03802d6afd28401aa47801270e82021 ]

When CONFIG_RODATA_FULL_DEFAULT_ENABLED=y, passing "rodata=on" on the
kernel command-line (rather than "rodata=full") should turn off the
"full" behaviour, leaving writable linear aliases of read-only kernel
memory. Unfortunately, the option has no effect in this situation and
the only way to disable the "rodata=full" behaviour is to disable rodata
protection entirely by passing "rodata=off".

Fix this by parsing the "on" and "off" options in the arch code,
additionally enforcing that 'rodata_full' cannot be set without also
setting 'rodata_enabled', allowing us to simplify a couple of checks
in the process.

Fixes: 2e8cff0a0eee ("arm64: fix rodata=full")
Cc: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Reviewed-by: "Russell King (Oracle)" &lt;rmk+kernel@armlinux.org.uk&gt;
Reviewed-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Link: https://lore.kernel.org/r/20231117131422.29663-1-will@kernel.org
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit acfa60dbe03802d6afd28401aa47801270e82021 ]

When CONFIG_RODATA_FULL_DEFAULT_ENABLED=y, passing "rodata=on" on the
kernel command-line (rather than "rodata=full") should turn off the
"full" behaviour, leaving writable linear aliases of read-only kernel
memory. Unfortunately, the option has no effect in this situation and
the only way to disable the "rodata=full" behaviour is to disable rodata
protection entirely by passing "rodata=off".

Fix this by parsing the "on" and "off" options in the arch code,
additionally enforcing that 'rodata_full' cannot be set without also
setting 'rodata_enabled', allowing us to simplify a couple of checks
in the process.

Fixes: 2e8cff0a0eee ("arm64: fix rodata=full")
Cc: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Reviewed-by: "Russell King (Oracle)" &lt;rmk+kernel@armlinux.org.uk&gt;
Reviewed-by: Ard Biesheuvel &lt;ardb@kernel.org&gt;
Link: https://lore.kernel.org/r/20231117131422.29663-1-will@kernel.org
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>s390/ipl: add missing IPL_TYPE_ECKD_DUMP case to ipl_init()</title>
<updated>2023-12-03T06:33:04+00:00</updated>
<author>
<name>Mikhail Zaslonko</name>
<email>zaslonko@linux.ibm.com</email>
</author>
<published>2023-11-08T17:18:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=322b3f6c90d4a4d0c0db0bd6169175fb098c23ed'/>
<id>322b3f6c90d4a4d0c0db0bd6169175fb098c23ed</id>
<content type='text'>
[ Upstream commit 673752a839694133a328610fcbc54f3d59ae87f3 ]

Add missing IPL_TYPE_ECKD_DUMP case to ipl_init() creating
ECKD ipl device attribute group similar to IPL_TYPE_ECKD case.
Commit e2d2a2968f2a ("s390/ipl: add eckd dump support") should
have had it from the beginning.

Fixes: e2d2a2968f2a ("s390/ipl: add eckd dump support")
Signed-off-by: Mikhail Zaslonko &lt;zaslonko@linux.ibm.com&gt;
Reviewed-by: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Signed-off-by: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 673752a839694133a328610fcbc54f3d59ae87f3 ]

Add missing IPL_TYPE_ECKD_DUMP case to ipl_init() creating
ECKD ipl device attribute group similar to IPL_TYPE_ECKD case.
Commit e2d2a2968f2a ("s390/ipl: add eckd dump support") should
have had it from the beginning.

Fixes: e2d2a2968f2a ("s390/ipl: add eckd dump support")
Signed-off-by: Mikhail Zaslonko &lt;zaslonko@linux.ibm.com&gt;
Reviewed-by: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Signed-off-by: Alexander Gordeev &lt;agordeev@linux.ibm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/srso: Move retbleed IBPB check into existing 'has_microcode' code block</title>
<updated>2023-11-28T17:20:16+00:00</updated>
<author>
<name>Josh Poimboeuf</name>
<email>jpoimboe@kernel.org</email>
</author>
<published>2023-09-05T05:04:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b4166941c03dc0b8b958ff3f295ad6e67f967a3d'/>
<id>b4166941c03dc0b8b958ff3f295ad6e67f967a3d</id>
<content type='text'>
commit 351236947a45a512c517153bbe109fe868d05e6d upstream.

Simplify the code flow a bit by moving the retbleed IBPB check into the
existing 'has_microcode' block.

Signed-off-by: Josh Poimboeuf &lt;jpoimboe@kernel.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Acked-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/0a22b86b1f6b07f9046a9ab763fc0e0d1b7a91d4.1693889988.git.jpoimboe@kernel.org
Cc: Caleb Jorden &lt;cjorden@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 351236947a45a512c517153bbe109fe868d05e6d upstream.

Simplify the code flow a bit by moving the retbleed IBPB check into the
existing 'has_microcode' block.

Signed-off-by: Josh Poimboeuf &lt;jpoimboe@kernel.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Acked-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Link: https://lore.kernel.org/r/0a22b86b1f6b07f9046a9ab763fc0e0d1b7a91d4.1693889988.git.jpoimboe@kernel.org
Cc: Caleb Jorden &lt;cjorden@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>riscv: kprobes: allow writing to x0</title>
<updated>2023-11-28T17:20:13+00:00</updated>
<author>
<name>Nam Cao</name>
<email>namcaov@gmail.com</email>
</author>
<published>2023-08-29T18:25:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b59f21292e1858477d4007d9645678b88ae17abf'/>
<id>b59f21292e1858477d4007d9645678b88ae17abf</id>
<content type='text'>
commit 8cb22bec142624d21bc85ff96b7bad10b6220e6a upstream.

Instructions can write to x0, so we should simulate these instructions
normally.

Currently, the kernel hangs if an instruction who writes to x0 is
simulated.

Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported")
Cc: stable@vger.kernel.org
Signed-off-by: Nam Cao &lt;namcaov@gmail.com&gt;
Reviewed-by: Charlie Jenkins &lt;charlie@rivosinc.com&gt;
Acked-by: Guo Ren &lt;guoren@kernel.org&gt;
Link: https://lore.kernel.org/r/20230829182500.61875-1-namcaov@gmail.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 8cb22bec142624d21bc85ff96b7bad10b6220e6a upstream.

Instructions can write to x0, so we should simulate these instructions
normally.

Currently, the kernel hangs if an instruction who writes to x0 is
simulated.

Fixes: c22b0bcb1dd0 ("riscv: Add kprobes supported")
Cc: stable@vger.kernel.org
Signed-off-by: Nam Cao &lt;namcaov@gmail.com&gt;
Reviewed-by: Charlie Jenkins &lt;charlie@rivosinc.com&gt;
Acked-by: Guo Ren &lt;guoren@kernel.org&gt;
Link: https://lore.kernel.org/r/20230829182500.61875-1-namcaov@gmail.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>riscv: correct pt_level name via pgtable_l5/4_enabled</title>
<updated>2023-11-28T17:20:13+00:00</updated>
<author>
<name>Song Shuai</name>
<email>suagrfillet@gmail.com</email>
</author>
<published>2023-08-30T04:39:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2c8b096a575000605da454d498369f5e15e9739b'/>
<id>2c8b096a575000605da454d498369f5e15e9739b</id>
<content type='text'>
commit e59e5e2754bf983fc58ad18f99b5eec01f1a0745 upstream.

The pt_level uses CONFIG_PGTABLE_LEVELS to display page table names.
But if page mode is downgraded from kernel cmdline or restricted by
the hardware in 64BIT, it will give a wrong name.

Like, using no4lvl for sv39, ptdump named the 1G-mapping as "PUD"
that should be "PGD":

0xffffffd840000000-0xffffffd900000000    0x00000000c0000000         3G PUD     D A G . . W R V

So select "P4D/PUD" or "PGD" via pgtable_l5/4_enabled to correct it.

Fixes: e8a62cc26ddf ("riscv: Implement sv48 support")
Reviewed-by: Alexandre Ghiti &lt;alexghiti@rivosinc.com&gt;
Signed-off-by: Song Shuai &lt;suagrfillet@gmail.com&gt;
Link: https://lore.kernel.org/r/20230712115740.943324-1-suagrfillet@gmail.com
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230830044129.11481-3-palmer@rivosinc.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit e59e5e2754bf983fc58ad18f99b5eec01f1a0745 upstream.

The pt_level uses CONFIG_PGTABLE_LEVELS to display page table names.
But if page mode is downgraded from kernel cmdline or restricted by
the hardware in 64BIT, it will give a wrong name.

Like, using no4lvl for sv39, ptdump named the 1G-mapping as "PUD"
that should be "PGD":

0xffffffd840000000-0xffffffd900000000    0x00000000c0000000         3G PUD     D A G . . W R V

So select "P4D/PUD" or "PGD" via pgtable_l5/4_enabled to correct it.

Fixes: e8a62cc26ddf ("riscv: Implement sv48 support")
Reviewed-by: Alexandre Ghiti &lt;alexghiti@rivosinc.com&gt;
Signed-off-by: Song Shuai &lt;suagrfillet@gmail.com&gt;
Link: https://lore.kernel.org/r/20230712115740.943324-1-suagrfillet@gmail.com
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230830044129.11481-3-palmer@rivosinc.com
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>riscv: mm: Update the comment of CONFIG_PAGE_OFFSET</title>
<updated>2023-11-28T17:20:13+00:00</updated>
<author>
<name>Song Shuai</name>
<email>suagrfillet@gmail.com</email>
</author>
<published>2023-08-09T03:10:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bf564cf9cac7d9e72c1455fc015f0b81408c3703'/>
<id>bf564cf9cac7d9e72c1455fc015f0b81408c3703</id>
<content type='text'>
commit 559fe94a449cba5b50a7cffea60474b385598c00 upstream.

Since the commit 011f09d12052 set sv57 as default for CONFIG_64BIT,
the comment of CONFIG_PAGE_OFFSET should be updated too.

Fixes: 011f09d12052 ("riscv: mm: Set sv57 on defaultly")
Signed-off-by: Song Shuai &lt;suagrfillet@gmail.com&gt;
Link: https://lore.kernel.org/r/20230809031023.3575407-1-songshuaishuai@tinylab.org
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 559fe94a449cba5b50a7cffea60474b385598c00 upstream.

Since the commit 011f09d12052 set sv57 as default for CONFIG_64BIT,
the comment of CONFIG_PAGE_OFFSET should be updated too.

Fixes: 011f09d12052 ("riscv: mm: Set sv57 on defaultly")
Signed-off-by: Song Shuai &lt;suagrfillet@gmail.com&gt;
Link: https://lore.kernel.org/r/20230809031023.3575407-1-songshuaishuai@tinylab.org
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>riscv: put interrupt entries into .irqentry.text</title>
<updated>2023-11-28T17:20:13+00:00</updated>
<author>
<name>Nam Cao</name>
<email>namcaov@gmail.com</email>
</author>
<published>2023-08-21T14:57:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a08b414d1ecec1ddc22b2d87f5c189aab1b3097b'/>
<id>a08b414d1ecec1ddc22b2d87f5c189aab1b3097b</id>
<content type='text'>
commit 87615e95f6f9ccd36d4a3905a2d87f91967ea9d2 upstream.

The interrupt entries are expected to be in the .irqentry.text section.
For example, for kprobes to work properly, exception code cannot be
probed; this is ensured by blacklisting addresses in the .irqentry.text
section.

Fixes: 7db91e57a0ac ("RISC-V: Task implementation")
Signed-off-by: Nam Cao &lt;namcaov@gmail.com&gt;
Link: https://lore.kernel.org/r/20230821145708.21270-1-namcaov@gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 87615e95f6f9ccd36d4a3905a2d87f91967ea9d2 upstream.

The interrupt entries are expected to be in the .irqentry.text section.
For example, for kprobes to work properly, exception code cannot be
probed; this is ensured by blacklisting addresses in the .irqentry.text
section.

Fixes: 7db91e57a0ac ("RISC-V: Task implementation")
Signed-off-by: Nam Cao &lt;namcaov@gmail.com&gt;
Link: https://lore.kernel.org/r/20230821145708.21270-1-namcaov@gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>riscv: Using TOOLCHAIN_HAS_ZIHINTPAUSE marco replace zihintpause</title>
<updated>2023-11-28T17:20:13+00:00</updated>
<author>
<name>Minda Chen</name>
<email>minda.chen@starfivetech.com</email>
</author>
<published>2023-08-02T06:42:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7aa18f77e1c2075c06829efa9903c0962b2f954a'/>
<id>7aa18f77e1c2075c06829efa9903c0962b2f954a</id>
<content type='text'>
commit dd16ac404a685cce07e67261a94c6225d90ea7ba upstream.

Actually it is a part of Conor's
commit aae538cd03bc ("riscv: fix detection of toolchain
Zihintpause support").
It is looks like a merge issue. Samuel's
commit 0b1d60d6dd9e ("riscv: Fix build with
CONFIG_CC_OPTIMIZE_FOR_SIZE=y") do not base on Conor's commit and
revert to __riscv_zihintpause. So this patch can fix it.

Signed-off-by: Minda Chen &lt;minda.chen@starfivetech.com&gt;
Fixes: 3c349eacc559 ("Merge patch "riscv: Fix build with CONFIG_CC_OPTIMIZE_FOR_SIZE=y"")
Reviewed-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Link: https://lore.kernel.org/r/20230802064215.31111-1-minda.chen@starfivetech.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit dd16ac404a685cce07e67261a94c6225d90ea7ba upstream.

Actually it is a part of Conor's
commit aae538cd03bc ("riscv: fix detection of toolchain
Zihintpause support").
It is looks like a merge issue. Samuel's
commit 0b1d60d6dd9e ("riscv: Fix build with
CONFIG_CC_OPTIMIZE_FOR_SIZE=y") do not base on Conor's commit and
revert to __riscv_zihintpause. So this patch can fix it.

Signed-off-by: Minda Chen &lt;minda.chen@starfivetech.com&gt;
Fixes: 3c349eacc559 ("Merge patch "riscv: Fix build with CONFIG_CC_OPTIMIZE_FOR_SIZE=y"")
Reviewed-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Link: https://lore.kernel.org/r/20230802064215.31111-1-minda.chen@starfivetech.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>LoongArch: Mark __percpu functions as always inline</title>
<updated>2023-11-28T17:20:12+00:00</updated>
<author>
<name>Nathan Chancellor</name>
<email>nathan@kernel.org</email>
</author>
<published>2023-11-08T06:12:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cff8bf67f126b1a330ada1a0fd8c98fd69f3cb1c'/>
<id>cff8bf67f126b1a330ada1a0fd8c98fd69f3cb1c</id>
<content type='text'>
commit 71945968d8b128c955204baa33ec03bdd91bdc26 upstream.

A recent change to the optimization pipeline in LLVM reveals some
fragility around the inlining of LoongArch's __percpu functions, which
manifests as a BUILD_BUG() failure:

  In file included from kernel/sched/build_policy.c:17:
  In file included from include/linux/sched/cputime.h:5:
  In file included from include/linux/sched/signal.h:5:
  In file included from include/linux/rculist.h:11:
  In file included from include/linux/rcupdate.h:26:
  In file included from include/linux/irqflags.h:18:
  arch/loongarch/include/asm/percpu.h:97:3: error: call to '__compiletime_assert_51' declared with 'error' attribute: BUILD_BUG failed
     97 |                 BUILD_BUG();
        |                 ^
  include/linux/build_bug.h:59:21: note: expanded from macro 'BUILD_BUG'
     59 | #define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
        |                     ^
  include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG'
     39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
        |                                     ^
  include/linux/compiler_types.h:425:2: note: expanded from macro 'compiletime_assert'
    425 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
        |         ^
  include/linux/compiler_types.h:413:2: note: expanded from macro '_compiletime_assert'
    413 |         __compiletime_assert(condition, msg, prefix, suffix)
        |         ^
  include/linux/compiler_types.h:406:4: note: expanded from macro '__compiletime_assert'
    406 |                         prefix ## suffix();                             \
        |                         ^
  &lt;scratch space&gt;:86:1: note: expanded from here
     86 | __compiletime_assert_51
        | ^
  1 error generated.

If these functions are not inlined (which the compiler is free to do
even with functions marked with the standard 'inline' keyword), the
BUILD_BUG() in the default case cannot be eliminated since the compiler
cannot prove it is never used, resulting in a build failure due to the
error attribute.

Mark these functions as __always_inline to guarantee inlining so that
the BUILD_BUG() only triggers when the default case genuinely cannot be
eliminated due to an unexpected size.

Cc:  &lt;stable@vger.kernel.org&gt;
Closes: https://github.com/ClangBuiltLinux/linux/issues/1955
Fixes: 46859ac8af52 ("LoongArch: Add multi-processor (SMP) support")
Link: https://github.com/llvm/llvm-project/commit/1a2e77cf9e11dbf56b5720c607313a566eebb16e
Suggested-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Huacai Chen &lt;chenhuacai@loongson.cn&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 71945968d8b128c955204baa33ec03bdd91bdc26 upstream.

A recent change to the optimization pipeline in LLVM reveals some
fragility around the inlining of LoongArch's __percpu functions, which
manifests as a BUILD_BUG() failure:

  In file included from kernel/sched/build_policy.c:17:
  In file included from include/linux/sched/cputime.h:5:
  In file included from include/linux/sched/signal.h:5:
  In file included from include/linux/rculist.h:11:
  In file included from include/linux/rcupdate.h:26:
  In file included from include/linux/irqflags.h:18:
  arch/loongarch/include/asm/percpu.h:97:3: error: call to '__compiletime_assert_51' declared with 'error' attribute: BUILD_BUG failed
     97 |                 BUILD_BUG();
        |                 ^
  include/linux/build_bug.h:59:21: note: expanded from macro 'BUILD_BUG'
     59 | #define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
        |                     ^
  include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG'
     39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
        |                                     ^
  include/linux/compiler_types.h:425:2: note: expanded from macro 'compiletime_assert'
    425 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
        |         ^
  include/linux/compiler_types.h:413:2: note: expanded from macro '_compiletime_assert'
    413 |         __compiletime_assert(condition, msg, prefix, suffix)
        |         ^
  include/linux/compiler_types.h:406:4: note: expanded from macro '__compiletime_assert'
    406 |                         prefix ## suffix();                             \
        |                         ^
  &lt;scratch space&gt;:86:1: note: expanded from here
     86 | __compiletime_assert_51
        | ^
  1 error generated.

If these functions are not inlined (which the compiler is free to do
even with functions marked with the standard 'inline' keyword), the
BUILD_BUG() in the default case cannot be eliminated since the compiler
cannot prove it is never used, resulting in a build failure due to the
error attribute.

Mark these functions as __always_inline to guarantee inlining so that
the BUILD_BUG() only triggers when the default case genuinely cannot be
eliminated due to an unexpected size.

Cc:  &lt;stable@vger.kernel.org&gt;
Closes: https://github.com/ClangBuiltLinux/linux/issues/1955
Fixes: 46859ac8af52 ("LoongArch: Add multi-processor (SMP) support")
Link: https://github.com/llvm/llvm-project/commit/1a2e77cf9e11dbf56b5720c607313a566eebb16e
Suggested-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Signed-off-by: Nathan Chancellor &lt;nathan@kernel.org&gt;
Signed-off-by: Huacai Chen &lt;chenhuacai@loongson.cn&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
