* [PATCH v3 0/4] arm64: put objects into proper sections
@ 2016-08-12 8:01 Jisheng Zhang
2016-08-12 8:01 ` [PATCH v3 1/4] arm64: vdso: add __init section marker to alloc_vectors_page Jisheng Zhang
` (3 more replies)
0 siblings, 4 replies; 12+ messages in thread
From: Jisheng Zhang @ 2016-08-12 8:01 UTC (permalink / raw)
To: catalin.marinas, will.deacon, lorenzo.pieralisi, keescook, mark.rutland
Cc: linux-arm-kernel, linux-kernel, Jisheng Zhang
This series tries to put some objects into proper sections.
patch1 puts alloc_vectors_page() into .init section. This is a clean up
patch.
patch2 constify vm_special_mapping used for aarch32 vectors page.
patch3 fix the incorrect placement of __initdata and __read_mostly
patch4 apply __ro_after_init to some objects
Previously I only want to mark vdso_pages, vdso_spec, vectors_page and
cpu_ops as __read_mostly for performance reason. Then inspired by
Kees's patch[1], I think __ro_after_init is better.
[1] http://www.spinics.net/lists/arm-kernel/msg523188.html
Changes since v2:
- include <linux/cache.h> for __ro_after_init, thank Mark's suggestions
- make vdso_spec[0].pages and vdso_spec[1].pages assignment style
consistent, thank Mark for pointing it out.
Changes since v1:
- use __ro_after_init instead of __read_mostly
- find more objects to be suitable for __ro_after_init
- add one more patch to fix the incorrect placement of __initdata and
__read_mostly
Jisheng Zhang (4):
arm64: vdso: add __init section marker to alloc_vectors_page
arm64: vdso: constify vm_special_mapping used for aarch32 vectors page
arm64: kaslr: Fix incorrect placement of __initdata and __read_mostly
arm64: apply __ro_after_init to some objects
arch/arm64/kernel/cpu_ops.c | 2 +-
arch/arm64/kernel/kaslr.c | 4 ++--
arch/arm64/kernel/vdso.c | 32 ++++++++++++++++----------------
arch/arm64/mm/dma-mapping.c | 2 +-
arch/arm64/mm/init.c | 4 ++--
arch/arm64/mm/mmu.c | 2 +-
6 files changed, 23 insertions(+), 23 deletions(-)
--
2.8.1
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH v3 1/4] arm64: vdso: add __init section marker to alloc_vectors_page
2016-08-12 8:01 [PATCH v3 0/4] arm64: put objects into proper sections Jisheng Zhang
@ 2016-08-12 8:01 ` Jisheng Zhang
2016-08-12 8:01 ` [PATCH v3 2/4] arm64: vdso: constify vm_special_mapping used for aarch32 vectors page Jisheng Zhang
` (2 subsequent siblings)
3 siblings, 0 replies; 12+ messages in thread
From: Jisheng Zhang @ 2016-08-12 8:01 UTC (permalink / raw)
To: catalin.marinas, will.deacon, lorenzo.pieralisi, keescook, mark.rutland
Cc: linux-arm-kernel, linux-kernel, Jisheng Zhang
It is not needed after booting, this patch moves the alloc_vectors_page
function to the __init section.
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
---
arch/arm64/kernel/vdso.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 076312b..e320e8f 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -55,7 +55,7 @@ struct vdso_data *vdso_data = &vdso_data_store.data;
*/
static struct page *vectors_page[1];
-static int alloc_vectors_page(void)
+static int __init alloc_vectors_page(void)
{
extern char __kuser_helper_start[], __kuser_helper_end[];
extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[];
--
2.8.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v3 2/4] arm64: vdso: constify vm_special_mapping used for aarch32 vectors page
2016-08-12 8:01 [PATCH v3 0/4] arm64: put objects into proper sections Jisheng Zhang
2016-08-12 8:01 ` [PATCH v3 1/4] arm64: vdso: add __init section marker to alloc_vectors_page Jisheng Zhang
@ 2016-08-12 8:01 ` Jisheng Zhang
2016-08-12 8:01 ` [PATCH v3 3/4] arm64: kaslr: Fix incorrect placement of __initdata and __read_mostly Jisheng Zhang
2016-08-12 8:01 ` [PATCH v3 4/4] arm64: apply __ro_after_init to some objects Jisheng Zhang
3 siblings, 0 replies; 12+ messages in thread
From: Jisheng Zhang @ 2016-08-12 8:01 UTC (permalink / raw)
To: catalin.marinas, will.deacon, lorenzo.pieralisi, keescook, mark.rutland
Cc: linux-arm-kernel, linux-kernel, Jisheng Zhang
The vm_special_mapping spec which is used for aarch32 vectors page is
never modified, so mark it as const.
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
---
arch/arm64/kernel/vdso.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index e320e8f..10ad8ab 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -88,7 +88,7 @@ int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
{
struct mm_struct *mm = current->mm;
unsigned long addr = AARCH32_VECTORS_BASE;
- static struct vm_special_mapping spec = {
+ static const struct vm_special_mapping spec = {
.name = "[vectors]",
.pages = vectors_page,
--
2.8.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v3 3/4] arm64: kaslr: Fix incorrect placement of __initdata and __read_mostly
2016-08-12 8:01 [PATCH v3 0/4] arm64: put objects into proper sections Jisheng Zhang
2016-08-12 8:01 ` [PATCH v3 1/4] arm64: vdso: add __init section marker to alloc_vectors_page Jisheng Zhang
2016-08-12 8:01 ` [PATCH v3 2/4] arm64: vdso: constify vm_special_mapping used for aarch32 vectors page Jisheng Zhang
@ 2016-08-12 8:01 ` Jisheng Zhang
2016-08-12 12:02 ` Ard Biesheuvel
2016-08-12 8:01 ` [PATCH v3 4/4] arm64: apply __ro_after_init to some objects Jisheng Zhang
3 siblings, 1 reply; 12+ messages in thread
From: Jisheng Zhang @ 2016-08-12 8:01 UTC (permalink / raw)
To: catalin.marinas, will.deacon, lorenzo.pieralisi, keescook, mark.rutland
Cc: linux-arm-kernel, linux-kernel, Jisheng Zhang
__initdata and __read_mostly should be placed after the variable name
for the variable to be placed in the intended section.
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
---
arch/arm64/kernel/kaslr.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c
index b054691..8ebabc4 100644
--- a/arch/arm64/kernel/kaslr.c
+++ b/arch/arm64/kernel/kaslr.c
@@ -20,8 +20,8 @@
#include <asm/pgtable.h>
#include <asm/sections.h>
-u64 __read_mostly module_alloc_base;
-u16 __initdata memstart_offset_seed;
+u64 module_alloc_base __read_mostly;
+u16 memstart_offset_seed __initdata;
static __init u64 get_kaslr_seed(void *fdt)
{
--
2.8.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH v3 4/4] arm64: apply __ro_after_init to some objects
2016-08-12 8:01 [PATCH v3 0/4] arm64: put objects into proper sections Jisheng Zhang
` (2 preceding siblings ...)
2016-08-12 8:01 ` [PATCH v3 3/4] arm64: kaslr: Fix incorrect placement of __initdata and __read_mostly Jisheng Zhang
@ 2016-08-12 8:01 ` Jisheng Zhang
2016-08-12 12:43 ` Mark Rutland
3 siblings, 1 reply; 12+ messages in thread
From: Jisheng Zhang @ 2016-08-12 8:01 UTC (permalink / raw)
To: catalin.marinas, will.deacon, lorenzo.pieralisi, keescook, mark.rutland
Cc: linux-arm-kernel, linux-kernel, Jisheng Zhang
These objects are set during initialization, thereafter are read only.
Previously I only want to mark vdso_pages, vdso_spec, vectors_page and
cpu_ops as __read_mostly from performance point of view. Then inspired
by Kees's patch[1] to apply more __ro_after_init for arm, I think it's
better to mark them as __ro_after_init. What's more, I find some more
objects are also read only after init. So apply __ro_after_init to all
of them.
This patch also removes global vdso_pagelist and tries to clean up
vdso_spec[] assignment code.
[1] http://www.spinics.net/lists/arm-kernel/msg523188.html
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
---
arch/arm64/kernel/cpu_ops.c | 2 +-
arch/arm64/kernel/kaslr.c | 2 +-
arch/arm64/kernel/vdso.c | 28 ++++++++++++++--------------
arch/arm64/mm/dma-mapping.c | 2 +-
arch/arm64/mm/init.c | 4 ++--
arch/arm64/mm/mmu.c | 2 +-
6 files changed, 20 insertions(+), 20 deletions(-)
diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c
index c7cfb8f..6d32d1a 100644
--- a/arch/arm64/kernel/cpu_ops.c
+++ b/arch/arm64/kernel/cpu_ops.c
@@ -28,7 +28,7 @@ extern const struct cpu_operations smp_spin_table_ops;
extern const struct cpu_operations acpi_parking_protocol_ops;
extern const struct cpu_operations cpu_psci_ops;
-const struct cpu_operations *cpu_ops[NR_CPUS];
+const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;
static const struct cpu_operations *dt_supported_cpu_ops[] __initconst = {
&smp_spin_table_ops,
diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c
index 8ebabc4..93c47e1 100644
--- a/arch/arm64/kernel/kaslr.c
+++ b/arch/arm64/kernel/kaslr.c
@@ -20,7 +20,7 @@
#include <asm/pgtable.h>
#include <asm/sections.h>
-u64 module_alloc_base __read_mostly;
+u64 module_alloc_base __ro_after_init;
u16 memstart_offset_seed __initdata;
static __init u64 get_kaslr_seed(void *fdt)
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 10ad8ab..c1ff7c2 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -19,6 +19,7 @@
*/
#include <linux/kernel.h>
+#include <linux/cache.h>
#include <linux/clocksource.h>
#include <linux/elf.h>
#include <linux/err.h>
@@ -37,8 +38,7 @@
#include <asm/vdso_datapage.h>
extern char vdso_start, vdso_end;
-static unsigned long vdso_pages;
-static struct page **vdso_pagelist;
+static unsigned long vdso_pages __ro_after_init;
/*
* The vDSO data page.
@@ -53,7 +53,7 @@ struct vdso_data *vdso_data = &vdso_data_store.data;
/*
* Create and map the vectors page for AArch32 tasks.
*/
-static struct page *vectors_page[1];
+static struct page *vectors_page[1] __ro_after_init;
static int __init alloc_vectors_page(void)
{
@@ -110,11 +110,19 @@ int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
}
#endif /* CONFIG_COMPAT */
-static struct vm_special_mapping vdso_spec[2];
+static struct vm_special_mapping vdso_spec[2] __ro_after_init = {
+ {
+ .name = "[vvar]",
+ },
+ {
+ .name = "[vdso]",
+ },
+};
static int __init vdso_init(void)
{
int i;
+ struct page **vdso_pagelist;
if (memcmp(&vdso_start, "\177ELF", 4)) {
pr_err("vDSO is not a valid ELF object!\n");
@@ -138,16 +146,8 @@ static int __init vdso_init(void)
for (i = 0; i < vdso_pages; i++)
vdso_pagelist[i + 1] = pfn_to_page(PHYS_PFN(__pa(&vdso_start)) + i);
- /* Populate the special mapping structures */
- vdso_spec[0] = (struct vm_special_mapping) {
- .name = "[vvar]",
- .pages = vdso_pagelist,
- };
-
- vdso_spec[1] = (struct vm_special_mapping) {
- .name = "[vdso]",
- .pages = &vdso_pagelist[1],
- };
+ vdso_spec[0].pages = &vdso_pagelist[0];
+ vdso_spec[1].pages = &vdso_pagelist[1];
return 0;
}
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index c4284c4..59d44e7 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -30,7 +30,7 @@
#include <asm/cacheflush.h>
-static int swiotlb __read_mostly;
+static int swiotlb __ro_after_init;
static pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot,
bool coherent)
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index bbb7ee7..e8b81ea 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -55,8 +55,8 @@
* executes, which assigns it its actual value. So use a default value
* that cannot be mistaken for a real physical address.
*/
-s64 memstart_addr __read_mostly = -1;
-phys_addr_t arm64_dma_phys_limit __read_mostly;
+s64 memstart_addr __ro_after_init = -1;
+phys_addr_t arm64_dma_phys_limit __ro_after_init;
#ifdef CONFIG_BLK_DEV_INITRD
static int __init early_initrd(char *p)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 4989948..6029bed 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -46,7 +46,7 @@
u64 idmap_t0sz = TCR_T0SZ(VA_BITS);
-u64 kimage_voffset __read_mostly;
+u64 kimage_voffset __ro_after_init;
EXPORT_SYMBOL(kimage_voffset);
/*
--
2.8.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH v3 3/4] arm64: kaslr: Fix incorrect placement of __initdata and __read_mostly
2016-08-12 8:01 ` [PATCH v3 3/4] arm64: kaslr: Fix incorrect placement of __initdata and __read_mostly Jisheng Zhang
@ 2016-08-12 12:02 ` Ard Biesheuvel
2016-08-15 4:52 ` Jisheng Zhang
0 siblings, 1 reply; 12+ messages in thread
From: Ard Biesheuvel @ 2016-08-12 12:02 UTC (permalink / raw)
To: Jisheng Zhang
Cc: Catalin Marinas, Will Deacon, Lorenzo Pieralisi, Kees Cook,
Mark Rutland, linux-kernel, linux-arm-kernel
Hi Jisheng,
On 12 August 2016 at 10:01, Jisheng Zhang <jszhang@marvell.com> wrote:
> __initdata and __read_mostly should be placed after the variable name
> for the variable to be placed in the intended section.
>
Why?
> Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> ---
> arch/arm64/kernel/kaslr.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c
> index b054691..8ebabc4 100644
> --- a/arch/arm64/kernel/kaslr.c
> +++ b/arch/arm64/kernel/kaslr.c
> @@ -20,8 +20,8 @@
> #include <asm/pgtable.h>
> #include <asm/sections.h>
>
> -u64 __read_mostly module_alloc_base;
> -u16 __initdata memstart_offset_seed;
> +u64 module_alloc_base __read_mostly;
> +u16 memstart_offset_seed __initdata;
>
> static __init u64 get_kaslr_seed(void *fdt)
> {
> --
> 2.8.1
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 4/4] arm64: apply __ro_after_init to some objects
2016-08-12 8:01 ` [PATCH v3 4/4] arm64: apply __ro_after_init to some objects Jisheng Zhang
@ 2016-08-12 12:43 ` Mark Rutland
2016-08-15 6:53 ` Jisheng Zhang
0 siblings, 1 reply; 12+ messages in thread
From: Mark Rutland @ 2016-08-12 12:43 UTC (permalink / raw)
To: Jisheng Zhang
Cc: catalin.marinas, will.deacon, lorenzo.pieralisi, keescook,
linux-arm-kernel, linux-kernel
Hi,
There are still a few missing includes as of this patch, and I have a
small nit about one file as commented below.
Please fix up the includes.
On Fri, Aug 12, 2016 at 04:01:11PM +0800, Jisheng Zhang wrote:
> diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c
> index c7cfb8f..6d32d1a 100644
> --- a/arch/arm64/kernel/cpu_ops.c
> +++ b/arch/arm64/kernel/cpu_ops.c
> @@ -28,7 +28,7 @@ extern const struct cpu_operations smp_spin_table_ops;
> extern const struct cpu_operations acpi_parking_protocol_ops;
> extern const struct cpu_operations cpu_psci_ops;
>
> -const struct cpu_operations *cpu_ops[NR_CPUS];
> +const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;
This file is missing a <linux/cache.h> include for __ro_after_init.
> static const struct cpu_operations *dt_supported_cpu_ops[] __initconst = {
> &smp_spin_table_ops,
> diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c
> index 8ebabc4..93c47e1 100644
> --- a/arch/arm64/kernel/kaslr.c
> +++ b/arch/arm64/kernel/kaslr.c
> @@ -20,7 +20,7 @@
> #include <asm/pgtable.h>
> #include <asm/sections.h>
>
> -u64 module_alloc_base __read_mostly;
> +u64 module_alloc_base __ro_after_init;
Likewise.
> u16 memstart_offset_seed __initdata;
>
> static __init u64 get_kaslr_seed(void *fdt)
> diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
> index 10ad8ab..c1ff7c2 100644
> --- a/arch/arm64/kernel/vdso.c
> +++ b/arch/arm64/kernel/vdso.c
> @@ -19,6 +19,7 @@
> */
>
> #include <linux/kernel.h>
> +#include <linux/cache.h>
> #include <linux/clocksource.h>
> #include <linux/elf.h>
> #include <linux/err.h>
Nit: Could you please sort this list? Everything but <linux/kernel.h> is
already in order.
> diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
> index c4284c4..59d44e7 100644
> --- a/arch/arm64/mm/dma-mapping.c
> +++ b/arch/arm64/mm/dma-mapping.c
> @@ -30,7 +30,7 @@
>
> #include <asm/cacheflush.h>
>
> -static int swiotlb __read_mostly;
> +static int swiotlb __ro_after_init;
This file is missing a <linux/cache.h> include for __ro_after_init.
>
> static pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot,
> bool coherent)
> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> index bbb7ee7..e8b81ea 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -55,8 +55,8 @@
> * executes, which assigns it its actual value. So use a default value
> * that cannot be mistaken for a real physical address.
> */
> -s64 memstart_addr __read_mostly = -1;
> -phys_addr_t arm64_dma_phys_limit __read_mostly;
> +s64 memstart_addr __ro_after_init = -1;
> +phys_addr_t arm64_dma_phys_limit __ro_after_init;
Likewise.
> #ifdef CONFIG_BLK_DEV_INITRD
> static int __init early_initrd(char *p)
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index 4989948..6029bed 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -46,7 +46,7 @@
>
> u64 idmap_t0sz = TCR_T0SZ(VA_BITS);
>
> -u64 kimage_voffset __read_mostly;
> +u64 kimage_voffset __ro_after_init;
Likewise.
Thanks,
Mark.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 3/4] arm64: kaslr: Fix incorrect placement of __initdata and __read_mostly
2016-08-12 12:02 ` Ard Biesheuvel
@ 2016-08-15 4:52 ` Jisheng Zhang
2016-08-15 5:57 ` Jisheng Zhang
0 siblings, 1 reply; 12+ messages in thread
From: Jisheng Zhang @ 2016-08-15 4:52 UTC (permalink / raw)
To: Ard Biesheuvel
Cc: Catalin Marinas, Will Deacon, Lorenzo Pieralisi, Kees Cook,
Mark Rutland, linux-kernel, linux-arm-kernel
Hi Ard,
On Fri, 12 Aug 2016 14:02:40 +0200 Ard Biesheuvel wrote:
> Hi Jisheng,
>
> On 12 August 2016 at 10:01, Jisheng Zhang <jszhang@marvell.com> wrote:
> > __initdata and __read_mostly should be placed after the variable name
> > for the variable to be placed in the intended section.
> >
>
> Why?
include/linux/init.h says something as:
* For initialized data:
* You should insert __initdata or __initconst between the variable name
* and equal sign followed by value, e.g.:
*
* static int init_variable __initdata = 0;
* static const char linux_logo[] __initconst = { 0x32, 0x36, ... };
and examples in gcc manual also put __attribute__ (...) after variable name.
https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#Common-Variable-Attributes
Then I grep the source, found most lines (especially arch/arm64/*) put the
__initdata and __read_mostly after the variable name.
However, I built the code with three different gcc, the result looks identical
no matter where these markers put. So the commit msg looks wrong, what about
changes it as
"put __initdata and __read_mostly after the variable name
to keep the style consistent"?
Thanks,
Jisheng
>
> > Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> > ---
> > arch/arm64/kernel/kaslr.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c
> > index b054691..8ebabc4 100644
> > --- a/arch/arm64/kernel/kaslr.c
> > +++ b/arch/arm64/kernel/kaslr.c
> > @@ -20,8 +20,8 @@
> > #include <asm/pgtable.h>
> > #include <asm/sections.h>
> >
> > -u64 __read_mostly module_alloc_base;
> > -u16 __initdata memstart_offset_seed;
> > +u64 module_alloc_base __read_mostly;
> > +u16 memstart_offset_seed __initdata;
> >
> > static __init u64 get_kaslr_seed(void *fdt)
> > {
> > --
> > 2.8.1
> >
> >
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 3/4] arm64: kaslr: Fix incorrect placement of __initdata and __read_mostly
2016-08-15 4:52 ` Jisheng Zhang
@ 2016-08-15 5:57 ` Jisheng Zhang
2016-08-15 6:30 ` Ard Biesheuvel
0 siblings, 1 reply; 12+ messages in thread
From: Jisheng Zhang @ 2016-08-15 5:57 UTC (permalink / raw)
To: Ard Biesheuvel
Cc: Mark Rutland, Lorenzo Pieralisi, Kees Cook, Catalin Marinas,
Will Deacon, linux-kernel, linux-arm-kernel
Hi Ard,
On Mon, 15 Aug 2016 12:52:14 +0800 Jisheng Zhang wrote:
> Hi Ard,
>
> On Fri, 12 Aug 2016 14:02:40 +0200 Ard Biesheuvel wrote:
>
> > Hi Jisheng,
> >
> > On 12 August 2016 at 10:01, Jisheng Zhang <jszhang@marvell.com> wrote:
> > > __initdata and __read_mostly should be placed after the variable name
> > > for the variable to be placed in the intended section.
> > >
> >
> > Why?
>
> include/linux/init.h says something as:
>
> * For initialized data:
> * You should insert __initdata or __initconst between the variable name
> * and equal sign followed by value, e.g.:
> *
> * static int init_variable __initdata = 0;
> * static const char linux_logo[] __initconst = { 0x32, 0x36, ... };
>
> and examples in gcc manual also put __attribute__ (...) after variable name.
>
> https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#Common-Variable-Attributes
>
> Then I grep the source, found most lines (especially arch/arm64/*) put the
> __initdata and __read_mostly after the variable name.
>
> However, I built the code with three different gcc, the result looks identical
> no matter where these markers put. So the commit msg looks wrong, what about
> changes it as
>
> "put __initdata and __read_mostly after the variable name
> to keep the style consistent"?
After some consideration, I want to drop this patch in newer version since
it's not a bug, just "style"
Thanks for your reviewing,
Jisheng
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 3/4] arm64: kaslr: Fix incorrect placement of __initdata and __read_mostly
2016-08-15 5:57 ` Jisheng Zhang
@ 2016-08-15 6:30 ` Ard Biesheuvel
0 siblings, 0 replies; 12+ messages in thread
From: Ard Biesheuvel @ 2016-08-15 6:30 UTC (permalink / raw)
To: Jisheng Zhang
Cc: Mark Rutland, Lorenzo Pieralisi, Kees Cook, Catalin Marinas,
Will Deacon, linux-kernel, linux-arm-kernel
On 15 August 2016 at 07:57, Jisheng Zhang <jszhang@marvell.com> wrote:
> Hi Ard,
>
> On Mon, 15 Aug 2016 12:52:14 +0800 Jisheng Zhang wrote:
>
>> Hi Ard,
>>
>> On Fri, 12 Aug 2016 14:02:40 +0200 Ard Biesheuvel wrote:
>>
>> > Hi Jisheng,
>> >
>> > On 12 August 2016 at 10:01, Jisheng Zhang <jszhang@marvell.com> wrote:
>> > > __initdata and __read_mostly should be placed after the variable name
>> > > for the variable to be placed in the intended section.
>> > >
>> >
>> > Why?
>>
>> include/linux/init.h says something as:
>>
>> * For initialized data:
>> * You should insert __initdata or __initconst between the variable name
>> * and equal sign followed by value, e.g.:
>> *
>> * static int init_variable __initdata = 0;
>> * static const char linux_logo[] __initconst = { 0x32, 0x36, ... };
>>
>> and examples in gcc manual also put __attribute__ (...) after variable name.
>>
>> https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#Common-Variable-Attributes
>>
>> Then I grep the source, found most lines (especially arch/arm64/*) put the
>> __initdata and __read_mostly after the variable name.
>>
>> However, I built the code with three different gcc, the result looks identical
>> no matter where these markers put. So the commit msg looks wrong, what about
>> changes it as
>>
>> "put __initdata and __read_mostly after the variable name
>> to keep the style consistent"?
>
> After some consideration, I want to drop this patch in newer version since
> it's not a bug, just "style"
>
OK, thanks for clearing that up. I don't object to the patch, but I
wanted to get confirmation that the current code is also correct.
Thanks,
Ard.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 4/4] arm64: apply __ro_after_init to some objects
2016-08-12 12:43 ` Mark Rutland
@ 2016-08-15 6:53 ` Jisheng Zhang
2016-08-15 9:07 ` Mark Rutland
0 siblings, 1 reply; 12+ messages in thread
From: Jisheng Zhang @ 2016-08-15 6:53 UTC (permalink / raw)
To: Mark Rutland
Cc: catalin.marinas, will.deacon, lorenzo.pieralisi, keescook,
linux-arm-kernel, linux-kernel
Hi Mark,
On Fri, 12 Aug 2016 13:43:45 +0100 Mark Rutland wrote:
> Hi,
>
> There are still a few missing includes as of this patch, and I have a
> small nit about one file as commented below.
>
> Please fix up the includes.
>
> On Fri, Aug 12, 2016 at 04:01:11PM +0800, Jisheng Zhang wrote:
> > diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c
> > index c7cfb8f..6d32d1a 100644
> > --- a/arch/arm64/kernel/cpu_ops.c
> > +++ b/arch/arm64/kernel/cpu_ops.c
> > @@ -28,7 +28,7 @@ extern const struct cpu_operations smp_spin_table_ops;
> > extern const struct cpu_operations acpi_parking_protocol_ops;
> > extern const struct cpu_operations cpu_psci_ops;
> >
> > -const struct cpu_operations *cpu_ops[NR_CPUS];
> > +const struct cpu_operations *cpu_ops[NR_CPUS] __ro_after_init;
>
> This file is missing a <linux/cache.h> include for __ro_after_init.
>
> > static const struct cpu_operations *dt_supported_cpu_ops[] __initconst = {
> > &smp_spin_table_ops,
> > diff --git a/arch/arm64/kernel/kaslr.c b/arch/arm64/kernel/kaslr.c
> > index 8ebabc4..93c47e1 100644
> > --- a/arch/arm64/kernel/kaslr.c
> > +++ b/arch/arm64/kernel/kaslr.c
> > @@ -20,7 +20,7 @@
> > #include <asm/pgtable.h>
> > #include <asm/sections.h>
> >
> > -u64 module_alloc_base __read_mostly;
> > +u64 module_alloc_base __ro_after_init;
>
> Likewise.
>
> > u16 memstart_offset_seed __initdata;
> >
> > static __init u64 get_kaslr_seed(void *fdt)
> > diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
> > index 10ad8ab..c1ff7c2 100644
> > --- a/arch/arm64/kernel/vdso.c
> > +++ b/arch/arm64/kernel/vdso.c
> > @@ -19,6 +19,7 @@
> > */
> >
> > #include <linux/kernel.h>
> > +#include <linux/cache.h>
> > #include <linux/clocksource.h>
> > #include <linux/elf.h>
> > #include <linux/err.h>
>
> Nit: Could you please sort this list? Everything but <linux/kernel.h> is
> already in order.
>
> > diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
> > index c4284c4..59d44e7 100644
> > --- a/arch/arm64/mm/dma-mapping.c
> > +++ b/arch/arm64/mm/dma-mapping.c
> > @@ -30,7 +30,7 @@
> >
> > #include <asm/cacheflush.h>
> >
> > -static int swiotlb __read_mostly;
> > +static int swiotlb __ro_after_init;
>
> This file is missing a <linux/cache.h> include for __ro_after_init.
>
> >
> > static pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot,
> > bool coherent)
> > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> > index bbb7ee7..e8b81ea 100644
> > --- a/arch/arm64/mm/init.c
> > +++ b/arch/arm64/mm/init.c
> > @@ -55,8 +55,8 @@
> > * executes, which assigns it its actual value. So use a default value
> > * that cannot be mistaken for a real physical address.
> > */
> > -s64 memstart_addr __read_mostly = -1;
> > -phys_addr_t arm64_dma_phys_limit __read_mostly;
> > +s64 memstart_addr __ro_after_init = -1;
> > +phys_addr_t arm64_dma_phys_limit __ro_after_init;
>
> Likewise.
>
> > #ifdef CONFIG_BLK_DEV_INITRD
> > static int __init early_initrd(char *p)
> > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> > index 4989948..6029bed 100644
> > --- a/arch/arm64/mm/mmu.c
> > +++ b/arch/arm64/mm/mmu.c
> > @@ -46,7 +46,7 @@
> >
> > u64 idmap_t0sz = TCR_T0SZ(VA_BITS);
> >
> > -u64 kimage_voffset __read_mostly;
> > +u64 kimage_voffset __ro_after_init;
>
> Likewise.
>
Thanks a lot, all comments are addressed in v4.
the headers in vdso.c is sorted now. However, the headers in mmu.c,
dma-mapping.c, init.c aren't, for I dunno whether it's acceptable
to do so. Or we could add one separate patch to make them sorted before
applying __ro_after_init
Thanks,
Jisheng
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH v3 4/4] arm64: apply __ro_after_init to some objects
2016-08-15 6:53 ` Jisheng Zhang
@ 2016-08-15 9:07 ` Mark Rutland
0 siblings, 0 replies; 12+ messages in thread
From: Mark Rutland @ 2016-08-15 9:07 UTC (permalink / raw)
To: Jisheng Zhang
Cc: catalin.marinas, will.deacon, lorenzo.pieralisi, keescook,
linux-arm-kernel, linux-kernel
Hi,
On Mon, Aug 15, 2016 at 02:53:03PM +0800, Jisheng Zhang wrote:
> On Fri, 12 Aug 2016 13:43:45 +0100 Mark Rutland wrote:
> > On Fri, Aug 12, 2016 at 04:01:11PM +0800, Jisheng Zhang wrote:
> > > diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
> > > index 10ad8ab..c1ff7c2 100644
> > > --- a/arch/arm64/kernel/vdso.c
> > > +++ b/arch/arm64/kernel/vdso.c
> > > @@ -19,6 +19,7 @@
> > > */
> > >
> > > #include <linux/kernel.h>
> > > +#include <linux/cache.h>
> > > #include <linux/clocksource.h>
> > > #include <linux/elf.h>
> > > #include <linux/err.h>
> >
> > Nit: Could you please sort this list? Everything but <linux/kernel.h> is
> > already in order.
[...]
> Thanks a lot, all comments are addressed in v4.
>
> the headers in vdso.c is sorted now. However, the headers in mmu.c,
> dma-mapping.c, init.c aren't, for I dunno whether it's acceptable
> to do so. Or we could add one separate patch to make them sorted before
> applying __ro_after_init
Ah. Given that's a little messy, it's probably not worthwhile sorting them.
Further, feel free to not bother sorting the vdso.c includes.
Thanks,
Mark.
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2016-08-15 9:09 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-08-12 8:01 [PATCH v3 0/4] arm64: put objects into proper sections Jisheng Zhang
2016-08-12 8:01 ` [PATCH v3 1/4] arm64: vdso: add __init section marker to alloc_vectors_page Jisheng Zhang
2016-08-12 8:01 ` [PATCH v3 2/4] arm64: vdso: constify vm_special_mapping used for aarch32 vectors page Jisheng Zhang
2016-08-12 8:01 ` [PATCH v3 3/4] arm64: kaslr: Fix incorrect placement of __initdata and __read_mostly Jisheng Zhang
2016-08-12 12:02 ` Ard Biesheuvel
2016-08-15 4:52 ` Jisheng Zhang
2016-08-15 5:57 ` Jisheng Zhang
2016-08-15 6:30 ` Ard Biesheuvel
2016-08-12 8:01 ` [PATCH v3 4/4] arm64: apply __ro_after_init to some objects Jisheng Zhang
2016-08-12 12:43 ` Mark Rutland
2016-08-15 6:53 ` Jisheng Zhang
2016-08-15 9:07 ` Mark Rutland
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