| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20210908190605.419064-2-keithpac@amazon.com>
Date: Wed, 8 Sep 2021 12:05:59 -0700
From: Keith Packard <keithpac@...zon.com>
To: linux-kernel@...r.kernel.org
Cc: Abbott Liu <liuwenliang@...wei.com>,
Alexei Starovoitov <ast@...nel.org>,
Andrew Morton <akpm@...ux-foundation.org>,
Andrii Nakryiko <andrii@...nel.org>,
Anshuman Khandual <anshuman.khandual@....com>,
Ard Biesheuvel <ardb@...nel.org>,
Arnd Bergmann <arnd@...db.de>, Ben Segall <bsegall@...gle.com>,
Bjorn Andersson <bjorn.andersson@...aro.org>,
bpf@...r.kernel.org, Christoph Lameter <cl@...ux.com>,
Daniel Borkmann <daniel@...earbox.net>,
Daniel Bristot de Oliveira <bristot@...hat.com>,
Dennis Zhou <dennis@...nel.org>, devicetree@...r.kernel.org,
Dietmar Eggemann <dietmar.eggemann@....com>,
Florian Fainelli <f.fainelli@...il.com>,
Frank Rowand <frowand.list@...il.com>,
Geert Uytterhoeven <geert+renesas@...der.be>,
Ingo Molnar <mingo@...hat.com>,
Jason Wang <jasowang@...hat.com>, Jens Axboe <axboe@...nel.dk>,
Joe Perches <joe@...ches.com>,
John Fastabend <john.fastabend@...il.com>,
Juri Lelli <juri.lelli@...hat.com>,
Keith Packard <keithpac@...zon.com>,
KP Singh <kpsingh@...nel.org>, kvm@...r.kernel.org,
Linus Walleij <linus.walleij@...aro.org>,
linux-arch@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
linux-mm@...ck.org, Manivannan Sadhasivam <mani@...nel.org>,
Marc Zyngier <maz@...nel.org>, Martin KaFai Lau <kafai@...com>,
Mel Gorman <mgorman@...e.de>,
Michael Ellerman <mpe@...erman.id.au>,
"Michael S. Tsirkin" <mst@...hat.com>,
Miguel Ojeda <ojeda@...nel.org>,
Mike Rapoport <rppt@...nel.org>, netdev@...r.kernel.org,
Nick Desaulniers <ndesaulniers@...gle.com>,
Nick Desaulniers <ndesaulniers@...ogle.com>,
Nicolas Pitre <nico@...xnic.net>,
Peter Zijlstra <peterz@...radead.org>,
Rob Herring <robh+dt@...nel.org>,
Russell King <linux@...linux.org.uk>,
Song Liu <songliubraving@...com>,
Srikar Dronamraju <srikar@...ux.vnet.ibm.com>,
Steven Rostedt <rostedt@...dmis.org>,
Tejun Heo <tj@...nel.org>,
Thomas Gleixner <tglx@...utronix.de>,
Uwe Kleine-König
<u.kleine-koenig@...gutronix.de>,
Valentin Schneider <valentin.schneider@....com>,
Vincent Guittot <vincent.guittot@...aro.org>,
virtualization@...ts.linux-foundation.org,
"Wolfram Sang (Renesas)" <wsa+renesas@...g-engineering.com>,
YiFei Zhu <yifeifz2@...inois.edu>, Yonghong Song <yhs@...com>
Subject: [PATCH v4 1/7] ARM: Pass cpu number to secondary_start_kernel
Instead of pulling the CPU value out of the thread_info struct, pass
it as an argument. When first initializing secondary processors, this
is done by stashing the value in the secondary_data struct. When
restarting idle processors, the previous CPU value is passed.
Because the cpu is now known at the top of secondary_start_kernel, the
per_cpu_offset value can now be set at this point, instead of in
cpu_init where it was also incorrectly setting the per_cpu_offset for
the boot processor before that value had been computed.
Signed-off-by: Keith Packard <keithpac@...zon.com>
Reviewed-by: Ard Biesheuvel <ardb@...nel.org>
---
arch/arm/include/asm/smp.h | 3 ++-
arch/arm/kernel/head-nommu.S | 1 +
arch/arm/kernel/head.S | 1 +
arch/arm/kernel/setup.c | 6 ------
arch/arm/kernel/smp.c | 14 +++++++++-----
5 files changed, 13 insertions(+), 12 deletions(-)
diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h
index 5d508f5d56c4..86a7fd721556 100644
--- a/arch/arm/include/asm/smp.h
+++ b/arch/arm/include/asm/smp.h
@@ -48,7 +48,7 @@ extern void set_smp_ipi_range(int ipi_base, int nr_ipi);
* Called from platform specific assembly code, this is the
* secondary CPU entry point.
*/
-asmlinkage void secondary_start_kernel(void);
+asmlinkage void secondary_start_kernel(unsigned int cpu);
/*
@@ -61,6 +61,7 @@ struct secondary_data {
};
unsigned long swapper_pg_dir;
void *stack;
+ unsigned int cpu;
};
extern struct secondary_data secondary_data;
extern void secondary_startup(void);
diff --git a/arch/arm/kernel/head-nommu.S b/arch/arm/kernel/head-nommu.S
index 0fc814bbc34b..5aa8ef42717f 100644
--- a/arch/arm/kernel/head-nommu.S
+++ b/arch/arm/kernel/head-nommu.S
@@ -114,6 +114,7 @@ ENTRY(secondary_startup)
add r12, r12, r10
ret r12
1: bl __after_proc_init
+ ldr r0, [r7, #16] @ set up cpu number
ldr sp, [r7, #12] @ set up the stack pointer
mov fp, #0
b secondary_start_kernel
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 7f62c5eccdf3..0e541af738e2 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -394,6 +394,7 @@ ENDPROC(secondary_startup_arm)
ENTRY(__secondary_switched)
ldr_l r7, secondary_data + 12 @ get secondary_data.stack
+ ldr_l r0, secondary_data + 16 @ get secondary_data.cpu
mov sp, r7
mov fp, #0
b secondary_start_kernel
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index 73ca7797b92f..ca0201635fac 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -532,12 +532,6 @@ void notrace cpu_init(void)
BUG();
}
- /*
- * This only works on resume and secondary cores. For booting on the
- * boot cpu, smp_prepare_boot_cpu is called after percpu area setup.
- */
- set_my_cpu_offset(per_cpu_offset(cpu));
-
cpu_proc_init();
/*
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 74679240a9d8..55cb1689a4b3 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -153,6 +153,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
secondary_data.pgdir = virt_to_phys(idmap_pgd);
secondary_data.swapper_pg_dir = get_arch_pgd(swapper_pg_dir);
#endif
+ secondary_data.cpu = cpu;
sync_cache_w(&secondary_data);
/*
@@ -373,11 +374,14 @@ void arch_cpu_idle_dead(void)
* cpu initialisation. There's some initialisation which needs
* to be repeated to undo the effects of taking the CPU offline.
*/
- __asm__("mov sp, %0\n"
+ __asm__("mov r0, %1\n"
+ " mov sp, %0\n"
" mov fp, #0\n"
" b secondary_start_kernel"
:
- : "r" (task_stack_page(current) + THREAD_SIZE - 8));
+ : "r" (task_stack_page(current) + THREAD_SIZE - 8),
+ "r" (cpu)
+ : "r0");
}
#endif /* CONFIG_HOTPLUG_CPU */
@@ -400,10 +404,11 @@ static void smp_store_cpu_info(unsigned int cpuid)
* This is the secondary CPU boot entry. We're using this CPUs
* idle thread stack, but a set of temporary page tables.
*/
-asmlinkage void secondary_start_kernel(void)
+asmlinkage void secondary_start_kernel(unsigned int cpu)
{
struct mm_struct *mm = &init_mm;
- unsigned int cpu;
+
+ set_my_cpu_offset(per_cpu_offset(cpu));
secondary_biglittle_init();
@@ -420,7 +425,6 @@ asmlinkage void secondary_start_kernel(void)
* All kernel threads share the same mm context; grab a
* reference and switch to it.
*/
- cpu = smp_processor_id();
mmgrab(mm);
current->active_mm = mm;
cpumask_set_cpu(cpu, mm_cpumask(mm));
--
2.33.0
Powered by blists - more mailing lists