From: Moritz Fischer <mdf@kernel.org> To: Marc Zyngier <maz@kernel.org> Cc: kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Ard Biesheuvel <ardb@kernel.org>, Mark Rutland <mark.rutland@arm.com>, James Morse <james.morse@arm.com>, Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>, Hanjun Guo <guohanjun@huawei.com>, Sudeep Holla <sudeep.holla@arm.com>, Eric Biederman <ebiederm@xmission.com>, Bhupesh Sharma <bhsharma@redhat.com>, AKASHI Takahiro <takahiro.akashi@linaro.org>, kernel-team@android.com Subject: Re: [PATCH 1/2] firmware/efi: Tell memblock about EFI reservations Date: Mon, 3 May 2021 11:56:36 -0700 [thread overview] Message-ID: <YJBHZFMhBL4z0445@epycbox.lan> (raw) In-Reply-To: <20210429133533.1750721-2-maz@kernel.org> Marc, On Thu, Apr 29, 2021 at 02:35:32PM +0100, Marc Zyngier wrote: > kexec_load_file() relies on the memblock infrastructure to avoid > stamping over regions of memory that are essential to the survival > of the system. > > However, nobody seems to agree how to flag these regions as reserved, > and (for example) EFI only publishes its reservations in /proc/iomem > for the benefit of the traditional, userspace based kexec tool. > > On arm64 platforms with GICv3, this can result in the payload being > placed at the location of the LPI tables. Shock, horror! > > Let's augment the EFI reservation code with a memblock_reserve() call, > protecting our dear tables from the secondary kernel invasion. > > At some point, someone will have to go and figure out a way to unify > these multiple reservation trees, because sprinkling random reservation > calls is only a temporary workaround. > Feel free to add (and/or): Reported-by: Moritz Fischer <mdf@kernel.org> Tested-by: Moritz Fischer <mdf@kernel.org> > Signed-off-by: Marc Zyngier <maz@kernel.org> > --- > drivers/firmware/efi/efi.c | 23 ++++++++++++++++++++++- > 1 file changed, 22 insertions(+), 1 deletion(-) > > diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c > index 4b7ee3fa9224..026b02f5f7d8 100644 > --- a/drivers/firmware/efi/efi.c > +++ b/drivers/firmware/efi/efi.c > @@ -896,11 +896,25 @@ static int __init efi_memreserve_map_root(void) > static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size) > { > struct resource *res, *parent; > + int ret; > > res = kzalloc(sizeof(struct resource), GFP_ATOMIC); > if (!res) > return -ENOMEM; > > + /* > + * Given that efi_mem_reserve_iomem() can be called at any > + * time, only call memblock_reserve() if the architecture > + * keeps the infrastructure around. > + */ > + if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { > + ret = memblock_reserve(addr, size); > + if (ret) { > + kfree(res); > + return ret; > + } > + } > + > res->name = "reserved"; > res->flags = IORESOURCE_MEM; > res->start = addr; > @@ -908,7 +922,14 @@ static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size) > > /* we expect a conflict with a 'System RAM' region */ > parent = request_resource_conflict(&iomem_resource, res); > - return parent ? request_resource(parent, res) : 0; > + ret = parent ? request_resource(parent, res) : 0; > + if (ret) { > + kfree(res); > + if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) > + memblock_free(addr, size); > + } > + > + return ret; > } > > int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size) > -- > 2.29.2 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel Thanks, Moritz _______________________________________________ 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: Moritz Fischer <mdf@kernel.org> To: Marc Zyngier <maz@kernel.org> Cc: kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Ard Biesheuvel <ardb@kernel.org>, Mark Rutland <mark.rutland@arm.com>, James Morse <james.morse@arm.com>, Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>, Hanjun Guo <guohanjun@huawei.com>, Sudeep Holla <sudeep.holla@arm.com>, Eric Biederman <ebiederm@xmission.com>, Bhupesh Sharma <bhsharma@redhat.com>, AKASHI Takahiro <takahiro.akashi@linaro.org>, kernel-team@android.com Subject: Re: [PATCH 1/2] firmware/efi: Tell memblock about EFI reservations Date: Mon, 3 May 2021 11:56:36 -0700 [thread overview] Message-ID: <YJBHZFMhBL4z0445@epycbox.lan> (raw) In-Reply-To: <20210429133533.1750721-2-maz@kernel.org> Marc, On Thu, Apr 29, 2021 at 02:35:32PM +0100, Marc Zyngier wrote: > kexec_load_file() relies on the memblock infrastructure to avoid > stamping over regions of memory that are essential to the survival > of the system. > > However, nobody seems to agree how to flag these regions as reserved, > and (for example) EFI only publishes its reservations in /proc/iomem > for the benefit of the traditional, userspace based kexec tool. > > On arm64 platforms with GICv3, this can result in the payload being > placed at the location of the LPI tables. Shock, horror! > > Let's augment the EFI reservation code with a memblock_reserve() call, > protecting our dear tables from the secondary kernel invasion. > > At some point, someone will have to go and figure out a way to unify > these multiple reservation trees, because sprinkling random reservation > calls is only a temporary workaround. > Feel free to add (and/or): Reported-by: Moritz Fischer <mdf@kernel.org> Tested-by: Moritz Fischer <mdf@kernel.org> > Signed-off-by: Marc Zyngier <maz@kernel.org> > --- > drivers/firmware/efi/efi.c | 23 ++++++++++++++++++++++- > 1 file changed, 22 insertions(+), 1 deletion(-) > > diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c > index 4b7ee3fa9224..026b02f5f7d8 100644 > --- a/drivers/firmware/efi/efi.c > +++ b/drivers/firmware/efi/efi.c > @@ -896,11 +896,25 @@ static int __init efi_memreserve_map_root(void) > static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size) > { > struct resource *res, *parent; > + int ret; > > res = kzalloc(sizeof(struct resource), GFP_ATOMIC); > if (!res) > return -ENOMEM; > > + /* > + * Given that efi_mem_reserve_iomem() can be called at any > + * time, only call memblock_reserve() if the architecture > + * keeps the infrastructure around. > + */ > + if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { > + ret = memblock_reserve(addr, size); > + if (ret) { > + kfree(res); > + return ret; > + } > + } > + > res->name = "reserved"; > res->flags = IORESOURCE_MEM; > res->start = addr; > @@ -908,7 +922,14 @@ static int efi_mem_reserve_iomem(phys_addr_t addr, u64 size) > > /* we expect a conflict with a 'System RAM' region */ > parent = request_resource_conflict(&iomem_resource, res); > - return parent ? request_resource(parent, res) : 0; > + ret = parent ? request_resource(parent, res) : 0; > + if (ret) { > + kfree(res); > + if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) > + memblock_free(addr, size); > + } > + > + return ret; > } > > int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size) > -- > 2.29.2 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel Thanks, Moritz _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2021-05-03 18:59 UTC|newest] Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-04-29 13:35 [PATCH 0/2] arm64: kexec_file_load vs memory reservations Marc Zyngier 2021-04-29 13:35 ` Marc Zyngier 2021-04-29 13:35 ` [PATCH 1/2] firmware/efi: Tell memblock about EFI reservations Marc Zyngier 2021-04-29 13:35 ` Marc Zyngier 2021-05-03 18:56 ` Moritz Fischer [this message] 2021-05-03 18:56 ` Moritz Fischer 2021-05-13 3:20 ` Dave Young 2021-05-13 3:20 ` Dave Young 2021-05-13 11:11 ` Marc Zyngier 2021-05-13 11:11 ` Marc Zyngier 2021-04-29 13:35 ` [PATCH 2/2] ACPI: arm64: Reserve the ACPI tables in memblock Marc Zyngier 2021-04-29 13:35 ` Marc Zyngier 2021-05-03 18:57 ` Moritz Fischer 2021-05-03 18:57 ` Moritz Fischer 2021-05-12 18:04 ` [PATCH 0/2] arm64: kexec_file_load vs memory reservations Marc Zyngier 2021-05-12 18:04 ` Marc Zyngier 2021-05-13 3:17 ` Dave Young 2021-05-13 3:17 ` Dave Young 2021-05-13 11:07 ` Marc Zyngier 2021-05-13 11:07 ` Marc Zyngier 2021-05-18 11:48 ` Will Deacon 2021-05-18 11:48 ` Will Deacon 2021-05-18 14:23 ` Bhupesh Sharma 2021-05-18 14:23 ` Bhupesh Sharma 2021-05-19 15:19 ` Catalin Marinas 2021-05-19 15:19 ` Catalin Marinas 2021-05-25 16:22 ` Marc Zyngier 2021-05-25 16:22 ` Marc Zyngier 2021-06-02 14:22 ` James Morse 2021-06-02 14:22 ` James Morse 2021-06-02 15:59 ` Marc Zyngier 2021-06-02 15:59 ` Marc Zyngier 2021-06-02 16:58 ` James Morse 2021-06-02 16:58 ` James Morse
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