Re: [PATCH 01/11] kexec_file: allow archs to handle special regions while locating memory hole
On 07/02/20 at 12:01am, Hari Bathini wrote:
>
>
> On 01/07/20 1:16 pm, Dave Young wrote:
> > On 06/29/20 at 05:26pm, Hari Bathini wrote:
> >> Hi Petr,
> >>
> >> On 29/06/20 5:09 pm, Petr Tesarik wrote:
> >>> Hi Hari,
> >>>
> >>> is there any good reason to add two more functions with a very similar
> >>> name to an existing function? AFAICS all you need is a way to call a
> >>> PPC64-specific function from within kexec_add_buffer (PATCH 4/11), so
> >>> you could add something like this:
> >>>
> >>> int __weak arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
> >>> {
> >>> return 0;
> >>> }
> >>>
> >>> Call this function from kexec_add_buffer where appropriate and then
> >>> override it for PPC64 (it roughly corresponds to your
> >>> kexec_locate_mem_hole_ppc64() from PATCH 4/11).
> >>>
> >>> FWIW it would make it easier for me to follow the resulting code.
> >>
> >> Right, Petr.
> >>
> >> I was trying out a few things before I ended up with what I sent here.
> >> Bu yeah.. I did realize arch_kexec_locate_mem_hole() would have been better
> >> after sending out v1. Will take care of that in v2.
> >
> > Another way is use arch private function to locate mem hole, then set
> > kbuf->mem, and then call kexec_add_buf, it will skip the common locate
> > hole function.
>
> Dave, I did think about it. But there are a couple of places this can get
> tricky. One is ima_add_kexec_buffer() and the other is kexec_elf_load().
> These call sites could be updated to set kbuf->mem before kexec_add_buffer().
> But the current approach seemed like the better option for it creates a
> single point of control in setting up segment buffers and also, makes adding
> any new segments simpler, arch-specific segments or otherwise.
>
Ok, thanks for the explanation.
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Re: [PATCH 01/11] kexec_file: allow archs to handle special regions while locating memory hole
On 01/07/20 1:16 pm, Dave Young wrote:
> On 06/29/20 at 05:26pm, Hari Bathini wrote:
>> Hi Petr,
>>
>> On 29/06/20 5:09 pm, Petr Tesarik wrote:
>>> Hi Hari,
>>>
>>> is there any good reason to add two more functions with a very similar
>>> name to an existing function? AFAICS all you need is a way to call a
>>> PPC64-specific function from within kexec_add_buffer (PATCH 4/11), so
>>> you could add something like this:
>>>
>>> int __weak arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
>>> {
>>> return 0;
>>> }
>>>
>>> Call this function from kexec_add_buffer where appropriate and then
>>> override it for PPC64 (it roughly corresponds to your
>>> kexec_locate_mem_hole_ppc64() from PATCH 4/11).
>>>
>>> FWIW it would make it easier for me to follow the resulting code.
>>
>> Right, Petr.
>>
>> I was trying out a few things before I ended up with what I sent here.
>> Bu yeah.. I did realize arch_kexec_locate_mem_hole() would have been better
>> after sending out v1. Will take care of that in v2.
>
> Another way is use arch private function to locate mem hole, then set
> kbuf->mem, and then call kexec_add_buf, it will skip the common locate
> hole function.
Dave, I did think about it. But there are a couple of places this can get
tricky. One is ima_add_kexec_buffer() and the other is kexec_elf_load().
These call sites could be updated to set kbuf->mem before kexec_add_buffer().
But the current approach seemed like the better option for it creates a
single point of control in setting up segment buffers and also, makes adding
any new segments simpler, arch-specific segments or otherwise.
Thanks
Hari
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Re: [PATCH 01/11] kexec_file: allow archs to handle special regions while locating memory hole
On 06/29/20 at 05:26pm, Hari Bathini wrote:
> Hi Petr,
>
> On 29/06/20 5:09 pm, Petr Tesarik wrote:
> > Hi Hari,
> >
> > is there any good reason to add two more functions with a very similar
> > name to an existing function? AFAICS all you need is a way to call a
> > PPC64-specific function from within kexec_add_buffer (PATCH 4/11), so
> > you could add something like this:
> >
> > int __weak arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
> > {
> > return 0;
> > }
> >
> > Call this function from kexec_add_buffer where appropriate and then
> > override it for PPC64 (it roughly corresponds to your
> > kexec_locate_mem_hole_ppc64() from PATCH 4/11).
> >
> > FWIW it would make it easier for me to follow the resulting code.
>
> Right, Petr.
>
> I was trying out a few things before I ended up with what I sent here.
> Bu yeah.. I did realize arch_kexec_locate_mem_hole() would have been better
> after sending out v1. Will take care of that in v2.
Another way is use arch private function to locate mem hole, then set
kbuf->mem, and then call kexec_add_buf, it will skip the common locate
hole function.
But other than that I have some confusion about those excluded ranges.
Replied a question to patch 4.
Thanks
Dave
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Re: [PATCH 01/11] kexec_file: allow archs to handle special regions while locating memory hole
Hi Hari,
is there any good reason to add two more functions with a very similar
name to an existing function? AFAICS all you need is a way to call a
PPC64-specific function from within kexec_add_buffer (PATCH 4/11), so
you could add something like this:
int __weak arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
{
return 0;
}
Call this function from kexec_add_buffer where appropriate and then
override it for PPC64 (it roughly corresponds to your
kexec_locate_mem_hole_ppc64() from PATCH 4/11).
FWIW it would make it easier for me to follow the resulting code.
Petr T
On Sat, 27 Jun 2020 00:34:43 +0530
Hari Bathini wrote:
> Some archs can have special memory regions, within the given memory
> range, which can't be used for the buffer in a kexec segment. As
> kexec_add_buffer() function is being called from generic code as well,
> add weak arch_kexec_add_buffer definition for archs to override & take
> care of special regions before trying to locate a memory hole.
>
> Signed-off-by: Hari Bathini
> ---
> include/linux/kexec.h |5 +
> kernel/kexec_file.c | 37 +
> 2 files changed, 38 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index 1776eb2..1237682 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -195,6 +195,11 @@ int __weak arch_kexec_apply_relocations(struct
> purgatory_info *pi,
> const Elf_Shdr *relsec,
> const Elf_Shdr *symtab);
>
> +extern int arch_kexec_add_buffer(struct kexec_buf *kbuf);
> +
> +/* arch_kexec_add_buffer calls this when it is ready */
> +extern int __kexec_add_buffer(struct kexec_buf *kbuf);
> +
> extern int kexec_add_buffer(struct kexec_buf *kbuf);
> int kexec_locate_mem_hole(struct kexec_buf *kbuf);
>
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index bb05fd5..a0b4f7f 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -669,10 +669,6 @@ int kexec_locate_mem_hole(struct kexec_buf *kbuf)
> */
> int kexec_add_buffer(struct kexec_buf *kbuf)
> {
> -
> - struct kexec_segment *ksegment;
> - int ret;
> -
> /* Currently adding segment this way is allowed only in file mode */
> if (!kbuf->image->file_mode)
> return -EINVAL;
> @@ -696,6 +692,25 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
> kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
> kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
>
> + return arch_kexec_add_buffer(kbuf);
> +}
> +
> +/**
> + * __kexec_add_buffer - arch_kexec_add_buffer would call this function after
> + * updating kbuf, to place a buffer in a kexec segment.
> + * @kbuf: Buffer contents and memory parameters.
> + *
> + * This function assumes that kexec_mutex is held.
> + * On successful return, @kbuf->mem will have the physical address of
> + * the buffer in memory.
> + *
> + * Return: 0 on success, negative errno on error.
> + */
> +int __kexec_add_buffer(struct kexec_buf *kbuf)
> +{
> + struct kexec_segment *ksegment;
> + int ret;
> +
> /* Walk the RAM ranges and allocate a suitable range for the buffer */
> ret = kexec_locate_mem_hole(kbuf);
> if (ret)
> @@ -711,6 +726,20 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
> return 0;
> }
>
> +/**
> + * arch_kexec_add_buffer - Some archs have memory regions within the given
> + * range that can't be used to place a kexec segment.
> + * Such archs can override this function to take care
> + * of them before trying to locate the memory hole.
> + * @kbuf: Buffer contents and memory parameters.
> + *
> + * Return: 0 on success, negative errno on error.
> + */
> +int __weak arch_kexec_add_buffer(struct kexec_buf *kbuf)
> +{
> + return __kexec_add_buffer(kbuf);
> +}
> +
> /* Calculate and store the digest of segments */
> static int kexec_calculate_store_digests(struct kimage *image)
> {
>
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Re: [PATCH 01/11] kexec_file: allow archs to handle special regions while locating memory hole
Hi Petr,
On 29/06/20 5:09 pm, Petr Tesarik wrote:
> Hi Hari,
>
> is there any good reason to add two more functions with a very similar
> name to an existing function? AFAICS all you need is a way to call a
> PPC64-specific function from within kexec_add_buffer (PATCH 4/11), so
> you could add something like this:
>
> int __weak arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
> {
> return 0;
> }
>
> Call this function from kexec_add_buffer where appropriate and then
> override it for PPC64 (it roughly corresponds to your
> kexec_locate_mem_hole_ppc64() from PATCH 4/11).
>
> FWIW it would make it easier for me to follow the resulting code.
Right, Petr.
I was trying out a few things before I ended up with what I sent here.
Bu yeah.. I did realize arch_kexec_locate_mem_hole() would have been better
after sending out v1. Will take care of that in v2.
Thanks
Hari
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Re: [PATCH 01/11] kexec_file: allow archs to handle special regions while locating memory hole
On 28/06/20 7:58 am, piliu wrote: > Hi Hari, > > If in [4/11], get_exclude_memory_ranges() turns out to be unnecessary > ,then this patch is abundant either. As my understanding, memblock has > already helped to achieved the purpose that get_exclude_memory_ranges() > wants. As mentioned in the other patch, there is a need for @exclude_ranges as crashkernel region is likely to have an overlap with regions like opal, rtas.. But yeah.. the weak function should have been kexec_locate_mem_hole() instead of kexec_add_buffer(). Will take care of that in v2. > On 06/27/2020 03:04 AM, Hari Bathini wrote: >> Some archs can have special memory regions, within the given memory >> range, which can't be used for the buffer in a kexec segment. As >> kexec_add_buffer() function is being called from generic code as well, >> add weak arch_kexec_add_buffer definition for archs to override & take >> care of special regions before trying to locate a memory hole. >> >> Signed-off-by: Hari Bathini Thanks Hari ___ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
Re: [PATCH 01/11] kexec_file: allow archs to handle special regions while locating memory hole
Hi Hari,
If in [4/11], get_exclude_memory_ranges() turns out to be unnecessary
,then this patch is abundant either. As my understanding, memblock has
already helped to achieved the purpose that get_exclude_memory_ranges()
wants.
Thanks,
Pingfan
On 06/27/2020 03:04 AM, Hari Bathini wrote:
> Some archs can have special memory regions, within the given memory
> range, which can't be used for the buffer in a kexec segment. As
> kexec_add_buffer() function is being called from generic code as well,
> add weak arch_kexec_add_buffer definition for archs to override & take
> care of special regions before trying to locate a memory hole.
>
> Signed-off-by: Hari Bathini
> ---
> include/linux/kexec.h |5 +
> kernel/kexec_file.c | 37 +
> 2 files changed, 38 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/kexec.h b/include/linux/kexec.h
> index 1776eb2..1237682 100644
> --- a/include/linux/kexec.h
> +++ b/include/linux/kexec.h
> @@ -195,6 +195,11 @@ int __weak arch_kexec_apply_relocations(struct
> purgatory_info *pi,
> const Elf_Shdr *relsec,
> const Elf_Shdr *symtab);
>
> +extern int arch_kexec_add_buffer(struct kexec_buf *kbuf);
> +
> +/* arch_kexec_add_buffer calls this when it is ready */
> +extern int __kexec_add_buffer(struct kexec_buf *kbuf);
> +
> extern int kexec_add_buffer(struct kexec_buf *kbuf);
> int kexec_locate_mem_hole(struct kexec_buf *kbuf);
>
> diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
> index bb05fd5..a0b4f7f 100644
> --- a/kernel/kexec_file.c
> +++ b/kernel/kexec_file.c
> @@ -669,10 +669,6 @@ int kexec_locate_mem_hole(struct kexec_buf *kbuf)
> */
> int kexec_add_buffer(struct kexec_buf *kbuf)
> {
> -
> - struct kexec_segment *ksegment;
> - int ret;
> -
> /* Currently adding segment this way is allowed only in file mode */
> if (!kbuf->image->file_mode)
> return -EINVAL;
> @@ -696,6 +692,25 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
> kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
> kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
>
> + return arch_kexec_add_buffer(kbuf);
> +}
> +
> +/**
> + * __kexec_add_buffer - arch_kexec_add_buffer would call this function after
> + * updating kbuf, to place a buffer in a kexec segment.
> + * @kbuf: Buffer contents and memory parameters.
> + *
> + * This function assumes that kexec_mutex is held.
> + * On successful return, @kbuf->mem will have the physical address of
> + * the buffer in memory.
> + *
> + * Return: 0 on success, negative errno on error.
> + */
> +int __kexec_add_buffer(struct kexec_buf *kbuf)
> +{
> + struct kexec_segment *ksegment;
> + int ret;
> +
> /* Walk the RAM ranges and allocate a suitable range for the buffer */
> ret = kexec_locate_mem_hole(kbuf);
> if (ret)
> @@ -711,6 +726,20 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
> return 0;
> }
>
> +/**
> + * arch_kexec_add_buffer - Some archs have memory regions within the given
> + * range that can't be used to place a kexec segment.
> + * Such archs can override this function to take care
> + * of them before trying to locate the memory hole.
> + * @kbuf: Buffer contents and memory parameters.
> + *
> + * Return: 0 on success, negative errno on error.
> + */
> +int __weak arch_kexec_add_buffer(struct kexec_buf *kbuf)
> +{
> + return __kexec_add_buffer(kbuf);
> +}
> +
> /* Calculate and store the digest of segments */
> static int kexec_calculate_store_digests(struct kimage *image)
> {
>
>
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Re: [PATCH 01/11] kexec_file: allow archs to handle special regions while locating memory hole
Le 26/06/2020 à 21:04, Hari Bathini a écrit :
Some archs can have special memory regions, within the given memory
range, which can't be used for the buffer in a kexec segment. As
kexec_add_buffer() function is being called from generic code as well,
add weak arch_kexec_add_buffer definition for archs to override & take
care of special regions before trying to locate a memory hole.
Signed-off-by: Hari Bathini
---
include/linux/kexec.h |5 +
kernel/kexec_file.c | 37 +
2 files changed, 38 insertions(+), 4 deletions(-)
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 1776eb2..1237682 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -195,6 +195,11 @@ int __weak arch_kexec_apply_relocations(struct
purgatory_info *pi,
const Elf_Shdr *relsec,
const Elf_Shdr *symtab);
+extern int arch_kexec_add_buffer(struct kexec_buf *kbuf);
+
extern keywork is useless here, please remove (checkpatch also complains
about it usually).
+/* arch_kexec_add_buffer calls this when it is ready */
+extern int __kexec_add_buffer(struct kexec_buf *kbuf);
+
same
extern int kexec_add_buffer(struct kexec_buf *kbuf);
int kexec_locate_mem_hole(struct kexec_buf *kbuf);
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index bb05fd5..a0b4f7f 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -669,10 +669,6 @@ int kexec_locate_mem_hole(struct kexec_buf *kbuf)
*/
int kexec_add_buffer(struct kexec_buf *kbuf)
{
-
- struct kexec_segment *ksegment;
- int ret;
-
/* Currently adding segment this way is allowed only in file mode */
if (!kbuf->image->file_mode)
return -EINVAL;
@@ -696,6 +692,25 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
+ return arch_kexec_add_buffer(kbuf);
+}
+
+/**
+ * __kexec_add_buffer - arch_kexec_add_buffer would call this function after
+ * updating kbuf, to place a buffer in a kexec segment.
+ * @kbuf: Buffer contents and memory parameters.
+ *
+ * This function assumes that kexec_mutex is held.
+ * On successful return, @kbuf->mem will have the physical address of
+ * the buffer in memory.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int __kexec_add_buffer(struct kexec_buf *kbuf)
+{
+ struct kexec_segment *ksegment;
+ int ret;
+
/* Walk the RAM ranges and allocate a suitable range for the buffer */
ret = kexec_locate_mem_hole(kbuf);
if (ret)
@@ -711,6 +726,20 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
return 0;
}
+/**
+ * arch_kexec_add_buffer - Some archs have memory regions within the given
+ * range that can't be used to place a kexec segment.
+ * Such archs can override this function to take care
+ * of them before trying to locate the memory hole.
+ * @kbuf: Buffer contents and memory parameters.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int __weak arch_kexec_add_buffer(struct kexec_buf *kbuf)
+{
+ return __kexec_add_buffer(kbuf);
+}
+
/* Calculate and store the digest of segments */
static int kexec_calculate_store_digests(struct kimage *image)
{
Christophe
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[PATCH 01/11] kexec_file: allow archs to handle special regions while locating memory hole
Some archs can have special memory regions, within the given memory
range, which can't be used for the buffer in a kexec segment. As
kexec_add_buffer() function is being called from generic code as well,
add weak arch_kexec_add_buffer definition for archs to override & take
care of special regions before trying to locate a memory hole.
Signed-off-by: Hari Bathini
---
include/linux/kexec.h |5 +
kernel/kexec_file.c | 37 +
2 files changed, 38 insertions(+), 4 deletions(-)
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 1776eb2..1237682 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -195,6 +195,11 @@ int __weak arch_kexec_apply_relocations(struct
purgatory_info *pi,
const Elf_Shdr *relsec,
const Elf_Shdr *symtab);
+extern int arch_kexec_add_buffer(struct kexec_buf *kbuf);
+
+/* arch_kexec_add_buffer calls this when it is ready */
+extern int __kexec_add_buffer(struct kexec_buf *kbuf);
+
extern int kexec_add_buffer(struct kexec_buf *kbuf);
int kexec_locate_mem_hole(struct kexec_buf *kbuf);
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index bb05fd5..a0b4f7f 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -669,10 +669,6 @@ int kexec_locate_mem_hole(struct kexec_buf *kbuf)
*/
int kexec_add_buffer(struct kexec_buf *kbuf)
{
-
- struct kexec_segment *ksegment;
- int ret;
-
/* Currently adding segment this way is allowed only in file mode */
if (!kbuf->image->file_mode)
return -EINVAL;
@@ -696,6 +692,25 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
+ return arch_kexec_add_buffer(kbuf);
+}
+
+/**
+ * __kexec_add_buffer - arch_kexec_add_buffer would call this function after
+ * updating kbuf, to place a buffer in a kexec segment.
+ * @kbuf: Buffer contents and memory parameters.
+ *
+ * This function assumes that kexec_mutex is held.
+ * On successful return, @kbuf->mem will have the physical address of
+ * the buffer in memory.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int __kexec_add_buffer(struct kexec_buf *kbuf)
+{
+ struct kexec_segment *ksegment;
+ int ret;
+
/* Walk the RAM ranges and allocate a suitable range for the buffer */
ret = kexec_locate_mem_hole(kbuf);
if (ret)
@@ -711,6 +726,20 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
return 0;
}
+/**
+ * arch_kexec_add_buffer - Some archs have memory regions within the given
+ * range that can't be used to place a kexec segment.
+ * Such archs can override this function to take care
+ * of them before trying to locate the memory hole.
+ * @kbuf: Buffer contents and memory parameters.
+ *
+ * Return: 0 on success, negative errno on error.
+ */
+int __weak arch_kexec_add_buffer(struct kexec_buf *kbuf)
+{
+ return __kexec_add_buffer(kbuf);
+}
+
/* Calculate and store the digest of segments */
static int kexec_calculate_store_digests(struct kimage *image)
{
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