From: Pavel Tatashin <pasha.tatashin@soleen.com>
To: James Morse <james.morse@arm.com>
Cc: jmorris@namei.org, sashal@kernel.org, ebiederm@xmission.com,
kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
corbet@lwn.net, catalin.marinas@arm.com, will@kernel.org,
linux-arm-kernel@lists.infradead.org, marc.zyngier@arm.com,
vladimir.murzin@arm.com, matthias.bgg@gmail.com,
bhsharma@redhat.com, linux-mm@kvack.org, mark.rutland@arm.com
Subject: Re: [PATCH v6 08/17] arm64: hibernate: add trans_pgd public functions
Date: Mon, 14 Oct 2019 15:34:19 +0000 [thread overview]
Message-ID: <20191014153419.galjhum7amnyuiml@soleen.tm1wkky2jk1uhgkn0ivaxijq1c.bx.internal.cloudapp.net> (raw)
In-Reply-To: <2ea69969-154d-fa55-767d-43ea8971dd0e@arm.com>
> > +
> > + memcpy(page, src_start, length);
> > + __flush_icache_range((unsigned long)page, (unsigned long)page + length);
> > +
> > + trans_pgd = (void *)get_safe_page(GFP_ATOMIC);
> > + if (!trans_pgd)
> > + return -ENOMEM;
> > +
> > + rc = trans_pgd_map_page(trans_pgd, page, dst_addr,
> > + PAGE_KERNEL_EXEC);
> > + if (rc)
> > + return rc;
> > +
> > /*
> > * Load our new page tables. A strict BBM approach requires that we
> > * ensure that TLBs are free of any entries that may overlap with the
>
> (I suspect you are going to to duplicate this in the kexec code. Kexec has the same
> pattern: instructions that have to be copied to do the relocation of the rest of memory)
>
Yes, the relocation function is also copied, but I do not see an easy
way to unify this particular code with kexec. We can discuss in kexec
part of this series what else can be unified with hibernate's code.
>
> > @@ -462,6 +476,24 @@ static int copy_page_tables(pgd_t *dst_pgdp, unsigned long start,
>
> > +int trans_pgd_create_copy(pgd_t **dst_pgdp, unsigned long start,
> > + unsigned long end)
> > +{
> > + int rc;
> > + pgd_t *trans_pgd = (pgd_t *)get_safe_page(GFP_ATOMIC);
> > +
> > + if (!trans_pgd) {
> > + pr_err("Failed to allocate memory for temporary page tables.\n");
> > + return -ENOMEM;
> > + }
> > +
> > + rc = copy_page_tables(trans_pgd, start, end);
> > + if (!rc)
> > + *dst_pgdp = trans_pgd;
>
> *dst_pgdp was already allocated in swsusp_arch_resume().
Good catch, I forgot to remove allocation from swsusp_arch_resume().
> > +
> > + return rc;
> > +}
> > +
> > /*
> > * Setup then Resume from the hibernate image using swsusp_arch_suspend_exit().
> > *
> > @@ -488,7 +520,7 @@ int swsusp_arch_resume(void)
> > pr_err("Failed to allocate memory for temporary page tables.\n");
> > return -ENOMEM;
> > }
>
> If the allocation moves into 'trans_pgd_create_copy()', please move the code just above
> here (cut off by the diff) that allocates it in swsusp_arch_resume().
>
> Its actually okay to leak memory like this, hibernate's allocator acts as a memory pool.
> It either gets freed if we fail to resume, or vanishes when the resumed kernel takes over.
I did.
>
> Reviewed-by: James Morse <james.morse@arm.com>
Thank you,
Pasha
WARNING: multiple messages have this Message-ID (diff)
From: Pavel Tatashin <pasha.tatashin@soleen.com>
To: James Morse <james.morse@arm.com>
Cc: sashal@kernel.org, mark.rutland@arm.com, vladimir.murzin@arm.com,
corbet@lwn.net, marc.zyngier@arm.com, catalin.marinas@arm.com,
bhsharma@redhat.com, kexec@lists.infradead.org,
linux-kernel@vger.kernel.org, jmorris@namei.org,
linux-mm@kvack.org, ebiederm@xmission.com,
matthias.bgg@gmail.com, will@kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v6 08/17] arm64: hibernate: add trans_pgd public functions
Date: Mon, 14 Oct 2019 15:34:19 +0000 [thread overview]
Message-ID: <20191014153419.galjhum7amnyuiml@soleen.tm1wkky2jk1uhgkn0ivaxijq1c.bx.internal.cloudapp.net> (raw)
In-Reply-To: <2ea69969-154d-fa55-767d-43ea8971dd0e@arm.com>
> > +
> > + memcpy(page, src_start, length);
> > + __flush_icache_range((unsigned long)page, (unsigned long)page + length);
> > +
> > + trans_pgd = (void *)get_safe_page(GFP_ATOMIC);
> > + if (!trans_pgd)
> > + return -ENOMEM;
> > +
> > + rc = trans_pgd_map_page(trans_pgd, page, dst_addr,
> > + PAGE_KERNEL_EXEC);
> > + if (rc)
> > + return rc;
> > +
> > /*
> > * Load our new page tables. A strict BBM approach requires that we
> > * ensure that TLBs are free of any entries that may overlap with the
>
> (I suspect you are going to to duplicate this in the kexec code. Kexec has the same
> pattern: instructions that have to be copied to do the relocation of the rest of memory)
>
Yes, the relocation function is also copied, but I do not see an easy
way to unify this particular code with kexec. We can discuss in kexec
part of this series what else can be unified with hibernate's code.
>
> > @@ -462,6 +476,24 @@ static int copy_page_tables(pgd_t *dst_pgdp, unsigned long start,
>
> > +int trans_pgd_create_copy(pgd_t **dst_pgdp, unsigned long start,
> > + unsigned long end)
> > +{
> > + int rc;
> > + pgd_t *trans_pgd = (pgd_t *)get_safe_page(GFP_ATOMIC);
> > +
> > + if (!trans_pgd) {
> > + pr_err("Failed to allocate memory for temporary page tables.\n");
> > + return -ENOMEM;
> > + }
> > +
> > + rc = copy_page_tables(trans_pgd, start, end);
> > + if (!rc)
> > + *dst_pgdp = trans_pgd;
>
> *dst_pgdp was already allocated in swsusp_arch_resume().
Good catch, I forgot to remove allocation from swsusp_arch_resume().
> > +
> > + return rc;
> > +}
> > +
> > /*
> > * Setup then Resume from the hibernate image using swsusp_arch_suspend_exit().
> > *
> > @@ -488,7 +520,7 @@ int swsusp_arch_resume(void)
> > pr_err("Failed to allocate memory for temporary page tables.\n");
> > return -ENOMEM;
> > }
>
> If the allocation moves into 'trans_pgd_create_copy()', please move the code just above
> here (cut off by the diff) that allocates it in swsusp_arch_resume().
>
> Its actually okay to leak memory like this, hibernate's allocator acts as a memory pool.
> It either gets freed if we fail to resume, or vanishes when the resumed kernel takes over.
I did.
>
> Reviewed-by: James Morse <james.morse@arm.com>
Thank you,
Pasha
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Pavel Tatashin <pasha.tatashin@soleen.com>
To: James Morse <james.morse@arm.com>
Cc: sashal@kernel.org, mark.rutland@arm.com, vladimir.murzin@arm.com,
corbet@lwn.net, marc.zyngier@arm.com, catalin.marinas@arm.com,
bhsharma@redhat.com, kexec@lists.infradead.org,
linux-kernel@vger.kernel.org, jmorris@namei.org,
linux-mm@kvack.org, ebiederm@xmission.com,
matthias.bgg@gmail.com, will@kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v6 08/17] arm64: hibernate: add trans_pgd public functions
Date: Mon, 14 Oct 2019 15:34:19 +0000 [thread overview]
Message-ID: <20191014153419.galjhum7amnyuiml@soleen.tm1wkky2jk1uhgkn0ivaxijq1c.bx.internal.cloudapp.net> (raw)
In-Reply-To: <2ea69969-154d-fa55-767d-43ea8971dd0e@arm.com>
> > +
> > + memcpy(page, src_start, length);
> > + __flush_icache_range((unsigned long)page, (unsigned long)page + length);
> > +
> > + trans_pgd = (void *)get_safe_page(GFP_ATOMIC);
> > + if (!trans_pgd)
> > + return -ENOMEM;
> > +
> > + rc = trans_pgd_map_page(trans_pgd, page, dst_addr,
> > + PAGE_KERNEL_EXEC);
> > + if (rc)
> > + return rc;
> > +
> > /*
> > * Load our new page tables. A strict BBM approach requires that we
> > * ensure that TLBs are free of any entries that may overlap with the
>
> (I suspect you are going to to duplicate this in the kexec code. Kexec has the same
> pattern: instructions that have to be copied to do the relocation of the rest of memory)
>
Yes, the relocation function is also copied, but I do not see an easy
way to unify this particular code with kexec. We can discuss in kexec
part of this series what else can be unified with hibernate's code.
>
> > @@ -462,6 +476,24 @@ static int copy_page_tables(pgd_t *dst_pgdp, unsigned long start,
>
> > +int trans_pgd_create_copy(pgd_t **dst_pgdp, unsigned long start,
> > + unsigned long end)
> > +{
> > + int rc;
> > + pgd_t *trans_pgd = (pgd_t *)get_safe_page(GFP_ATOMIC);
> > +
> > + if (!trans_pgd) {
> > + pr_err("Failed to allocate memory for temporary page tables.\n");
> > + return -ENOMEM;
> > + }
> > +
> > + rc = copy_page_tables(trans_pgd, start, end);
> > + if (!rc)
> > + *dst_pgdp = trans_pgd;
>
> *dst_pgdp was already allocated in swsusp_arch_resume().
Good catch, I forgot to remove allocation from swsusp_arch_resume().
> > +
> > + return rc;
> > +}
> > +
> > /*
> > * Setup then Resume from the hibernate image using swsusp_arch_suspend_exit().
> > *
> > @@ -488,7 +520,7 @@ int swsusp_arch_resume(void)
> > pr_err("Failed to allocate memory for temporary page tables.\n");
> > return -ENOMEM;
> > }
>
> If the allocation moves into 'trans_pgd_create_copy()', please move the code just above
> here (cut off by the diff) that allocates it in swsusp_arch_resume().
>
> Its actually okay to leak memory like this, hibernate's allocator acts as a memory pool.
> It either gets freed if we fail to resume, or vanishes when the resumed kernel takes over.
I did.
>
> Reviewed-by: James Morse <james.morse@arm.com>
Thank you,
Pasha
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2019-10-14 15:34 UTC|newest]
Thread overview: 93+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-04 18:52 [PATCH v6 00/17] arm64: MMU enabled kexec relocation Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 01/17] kexec: quiet down kexec reboot Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 02/17] arm64: hibernate: pass the allocated pgdp to ttbr0 Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-11 18:17 ` James Morse
2019-10-11 18:17 ` James Morse
2019-10-11 18:17 ` James Morse
2019-10-14 14:11 ` Pavel Tatashin
2019-10-14 14:11 ` Pavel Tatashin
2019-10-14 14:11 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 03/17] arm64: hibernate: check pgd table allocation Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-11 18:17 ` James Morse
2019-10-11 18:17 ` James Morse
2019-10-11 18:17 ` James Morse
2019-10-14 14:51 ` Pavel Tatashin
2019-10-14 14:51 ` Pavel Tatashin
2019-10-14 14:51 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 04/17] arm64: hibernate: use get_safe_page directly Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 05/17] arm64: hibernate: remove gotos as they are not needed Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 06/17] arm64: hibernate: rename dst to page in create_safe_exec_page Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 07/17] arm64: hibernate: add PUD_SECT_RDONLY Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 08/17] arm64: hibernate: add trans_pgd public functions Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-11 18:18 ` James Morse
2019-10-11 18:18 ` James Morse
2019-10-11 18:18 ` James Morse
2019-10-14 15:34 ` Pavel Tatashin [this message]
2019-10-14 15:34 ` Pavel Tatashin
2019-10-14 15:34 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 09/17] arm64: hibernate: move page handling function to new trans_pgd.c Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 10/17] arm64: trans_pgd: make trans_pgd_map_page generic Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 11/17] arm64: trans_pgd: pass allocator trans_pgd_create_copy Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 12/17] arm64: trans_pgd: pass NULL instead of init_mm to *_populate functions Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 13/17] kexec: add machine_kexec_post_load() Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 14/17] arm64: kexec: move relocation function setup and clean up Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-11 18:19 ` James Morse
2019-10-11 18:19 ` James Morse
2019-10-11 18:19 ` James Morse
2019-10-14 19:29 ` Pavel Tatashin
2019-10-14 19:29 ` Pavel Tatashin
2019-10-14 19:29 ` Pavel Tatashin
2019-10-14 19:29 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 15/17] arm64: kexec: add expandable argument to relocation function Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-11 18:19 ` James Morse
2019-10-11 18:19 ` James Morse
2019-10-11 18:19 ` James Morse
2019-10-14 23:35 ` Pavel Tatashin
2019-10-14 23:35 ` Pavel Tatashin
2019-10-14 23:35 ` Pavel Tatashin
2019-10-14 23:35 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 16/17] arm64: kexec: configure trans_pgd page table for kexec Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-11 18:21 ` James Morse
2019-10-11 18:21 ` James Morse
2019-10-11 18:21 ` James Morse
2019-10-15 2:12 ` Pavel Tatashin
2019-10-15 2:12 ` Pavel Tatashin
2019-10-15 2:12 ` Pavel Tatashin
2019-10-15 2:12 ` Pavel Tatashin
2019-10-04 18:52 ` [PATCH v6 17/17] arm64: kexec: enable MMU during kexec relocation Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
2019-10-04 18:52 ` Pavel Tatashin
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