| Message ID | 1550674294-10473-2-git-send-email-paolo.pisati@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | efi/arm/arm64: Allow SetVirtualAddressMap() to be omitted | expand |
On 20/02/2019 14:51, Paolo Pisati wrote: > From: Ard Biesheuvel <ard.biesheuvel@linaro.org> > > The UEFI spec revision 2.7 errata A section 8.4 has the following to > say about the virtual memory runtime services: > > "This section contains function definitions for the virtual memory > support that may be optionally used by an operating system at runtime. > If an operating system chooses to make EFI runtime service calls in a > virtual addressing mode instead of the flat physical mode, then the > operating system must use the services in this section to switch the > EFI runtime services from flat physical addressing to virtual > addressing." > > So it is pretty clear that calling SetVirtualAddressMap() is entirely > optional, and so there is no point in doing so unless it achieves > anything useful for us. > > This is not the case for 64-bit ARM. The identity mapping used by the > firmware is arbitrarily converted into another permutation of userland > addresses (i.e., bits [63:48] cleared), and the runtime code could easily > deal with the original layout in exactly the same way as it deals with > the converted layout. However, due to constraints related to page size > differences if the OS is not running with 4k pages, and related to > systems that may expose the individual sections of PE/COFF runtime > modules as different memory regions, creating the virtual layout is a > bit fiddly, and requires us to sort the memory map and reason about > adjacent regions with identical memory types etc etc. > > So the obvious fix is to stop calling SetVirtualAddressMap() altogether > on arm64 systems. However, to avoid surprises, which are notoriously > hard to diagnose when it comes to OS<->firmware interactions, let's > start by making it an opt-out feature, and implement support for the > 'efi=novamap' kernel command line parameter on ARM and arm64 systems. > > ( Note that 32-bit ARM generally does require SetVirtualAddressMap() to be > used, given that the physical memory map and the kernel virtual address > map are not guaranteed to be non-overlapping like on arm64. However, > having support for efi=novamap,noruntime on 32-bit ARM, combined with > the recently proposed support for earlycon=efifb, is likely to be useful > to diagnose boot issues on such systems if they have no accessible serial > port. ) > > Tested-by: Jeffrey Hugo <jhugo@codeaurora.org> > Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org> > Tested-by: Lee Jones <lee.jones@linaro.org> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> > Cc: Alexander Graf <agraf@suse.de> > Cc: Borislav Petkov <bp@alien8.de> > Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> > Cc: Leif Lindholm <leif.lindholm@linaro.org> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Cc: Matt Fleming <matt@codeblueprint.co.uk> > Cc: Peter Jones <pjones@redhat.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: linux-efi@vger.kernel.org > Link: http://lkml.kernel.org/r/20190202094119.13230-8-ard.biesheuvel@linaro.org > Signed-off-by: Ingo Molnar <mingo@kernel.org> > (cherry picked from commit 4e46c2a956215482418d7b315749fb1b6c6bc224) > Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com> > --- > drivers/firmware/efi/libstub/arm-stub.c | 5 +++++ > drivers/firmware/efi/libstub/efi-stub-helper.c | 10 ++++++++++ > drivers/firmware/efi/libstub/efistub.h | 1 + > drivers/firmware/efi/libstub/fdt.c | 3 +++ > 4 files changed, 19 insertions(+) > > diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c > index 01a9d78..3b1e1dc 100644 > --- a/drivers/firmware/efi/libstub/arm-stub.c > +++ b/drivers/firmware/efi/libstub/arm-stub.c > @@ -364,6 +364,11 @@ void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size, > paddr = in->phys_addr; > size = in->num_pages * EFI_PAGE_SIZE; > > + if (novamap()) { > + in->virt_addr = in->phys_addr; > + continue; > + } > + > /* > * Make the mapping compatible with 64k pages: this allows > * a 4k page size kernel to kexec a 64k page size kernel and > diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c > index 50a9cab..39f87e6 100644 > --- a/drivers/firmware/efi/libstub/efi-stub-helper.c > +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c > @@ -34,6 +34,7 @@ static unsigned long __chunk_size = EFI_READ_CHUNK_SIZE; > > static int __section(.data) __nokaslr; > static int __section(.data) __quiet; > +static int __section(.data) __novamap; > > int __pure nokaslr(void) > { > @@ -43,6 +44,10 @@ int __pure is_quiet(void) > { > return __quiet; > } > +int __pure novamap(void) > +{ > + return __novamap; > +} > > #define EFI_MMAP_NR_SLACK_SLOTS 8 > > @@ -454,6 +459,11 @@ efi_status_t efi_parse_options(char const *cmdline) > __chunk_size = -1UL; > } > > + if (!strncmp(str, "novamap", 7)) { > + str += strlen("novamap"); > + __novamap = 1; > + } > + > /* Group words together, delimited by "," */ > while (*str && *str != ' ' && *str != ',') > str++; > diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h > index f59564b..2adde22 100644 > --- a/drivers/firmware/efi/libstub/efistub.h > +++ b/drivers/firmware/efi/libstub/efistub.h > @@ -27,6 +27,7 @@ > > extern int __pure nokaslr(void); > extern int __pure is_quiet(void); > +extern int __pure novamap(void); > > #define pr_efi(sys_table, msg) do { \ > if (!is_quiet()) efi_printk(sys_table, "EFI stub: "msg); \ > diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c > index 8830fa6..94e7115 100644 > --- a/drivers/firmware/efi/libstub/fdt.c > +++ b/drivers/firmware/efi/libstub/fdt.c > @@ -323,6 +323,9 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, > if (status == EFI_SUCCESS) { > efi_set_virtual_address_map_t *svam; > > + if (novamap()) > + return EFI_SUCCESS; > + > /* Install the new virtual address map */ > svam = sys_table->runtime->set_virtual_address_map; > status = svam(runtime_entry_count * desc_size, desc_size, > Missing buglink in the commit. Upstream patch, has had regression testing upstream and is an opt-out option so regression potential is low. Acked-by: Colin Ian King <colin.king@canonical.com>
On 20.02.19 15:51, Paolo Pisati wrote: > From: Ard Biesheuvel <ard.biesheuvel@linaro.org> BugLink: https://bugs.launchpad.net/bugs/1814982 > > The UEFI spec revision 2.7 errata A section 8.4 has the following to > say about the virtual memory runtime services: > > "This section contains function definitions for the virtual memory > support that may be optionally used by an operating system at runtime. > If an operating system chooses to make EFI runtime service calls in a > virtual addressing mode instead of the flat physical mode, then the > operating system must use the services in this section to switch the > EFI runtime services from flat physical addressing to virtual > addressing." > > So it is pretty clear that calling SetVirtualAddressMap() is entirely > optional, and so there is no point in doing so unless it achieves > anything useful for us. > > This is not the case for 64-bit ARM. The identity mapping used by the > firmware is arbitrarily converted into another permutation of userland > addresses (i.e., bits [63:48] cleared), and the runtime code could easily > deal with the original layout in exactly the same way as it deals with > the converted layout. However, due to constraints related to page size > differences if the OS is not running with 4k pages, and related to > systems that may expose the individual sections of PE/COFF runtime > modules as different memory regions, creating the virtual layout is a > bit fiddly, and requires us to sort the memory map and reason about > adjacent regions with identical memory types etc etc. > > So the obvious fix is to stop calling SetVirtualAddressMap() altogether > on arm64 systems. However, to avoid surprises, which are notoriously > hard to diagnose when it comes to OS<->firmware interactions, let's > start by making it an opt-out feature, and implement support for the > 'efi=novamap' kernel command line parameter on ARM and arm64 systems. > > ( Note that 32-bit ARM generally does require SetVirtualAddressMap() to be > used, given that the physical memory map and the kernel virtual address > map are not guaranteed to be non-overlapping like on arm64. However, > having support for efi=novamap,noruntime on 32-bit ARM, combined with > the recently proposed support for earlycon=efifb, is likely to be useful > to diagnose boot issues on such systems if they have no accessible serial > port. ) > > Tested-by: Jeffrey Hugo <jhugo@codeaurora.org> > Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org> > Tested-by: Lee Jones <lee.jones@linaro.org> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> > Cc: Alexander Graf <agraf@suse.de> > Cc: Borislav Petkov <bp@alien8.de> > Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> > Cc: Leif Lindholm <leif.lindholm@linaro.org> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Cc: Matt Fleming <matt@codeblueprint.co.uk> > Cc: Peter Jones <pjones@redhat.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: linux-efi@vger.kernel.org > Link: http://lkml.kernel.org/r/20190202094119.13230-8-ard.biesheuvel@linaro.org > Signed-off-by: Ingo Molnar <mingo@kernel.org> > (cherry picked from commit 4e46c2a956215482418d7b315749fb1b6c6bc224) > Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com> Acked-by: Stefan Bader <stefan.bader@canonical.com> > --- With BugLink added as opt-out and testable. > drivers/firmware/efi/libstub/arm-stub.c | 5 +++++ > drivers/firmware/efi/libstub/efi-stub-helper.c | 10 ++++++++++ > drivers/firmware/efi/libstub/efistub.h | 1 + > drivers/firmware/efi/libstub/fdt.c | 3 +++ > 4 files changed, 19 insertions(+) > > diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c > index 01a9d78..3b1e1dc 100644 > --- a/drivers/firmware/efi/libstub/arm-stub.c > +++ b/drivers/firmware/efi/libstub/arm-stub.c > @@ -364,6 +364,11 @@ void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size, > paddr = in->phys_addr; > size = in->num_pages * EFI_PAGE_SIZE; > > + if (novamap()) { > + in->virt_addr = in->phys_addr; > + continue; > + } > + > /* > * Make the mapping compatible with 64k pages: this allows > * a 4k page size kernel to kexec a 64k page size kernel and > diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c > index 50a9cab..39f87e6 100644 > --- a/drivers/firmware/efi/libstub/efi-stub-helper.c > +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c > @@ -34,6 +34,7 @@ static unsigned long __chunk_size = EFI_READ_CHUNK_SIZE; > > static int __section(.data) __nokaslr; > static int __section(.data) __quiet; > +static int __section(.data) __novamap; > > int __pure nokaslr(void) > { > @@ -43,6 +44,10 @@ int __pure is_quiet(void) > { > return __quiet; > } > +int __pure novamap(void) > +{ > + return __novamap; > +} > > #define EFI_MMAP_NR_SLACK_SLOTS 8 > > @@ -454,6 +459,11 @@ efi_status_t efi_parse_options(char const *cmdline) > __chunk_size = -1UL; > } > > + if (!strncmp(str, "novamap", 7)) { > + str += strlen("novamap"); > + __novamap = 1; > + } > + > /* Group words together, delimited by "," */ > while (*str && *str != ' ' && *str != ',') > str++; > diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h > index f59564b..2adde22 100644 > --- a/drivers/firmware/efi/libstub/efistub.h > +++ b/drivers/firmware/efi/libstub/efistub.h > @@ -27,6 +27,7 @@ > > extern int __pure nokaslr(void); > extern int __pure is_quiet(void); > +extern int __pure novamap(void); > > #define pr_efi(sys_table, msg) do { \ > if (!is_quiet()) efi_printk(sys_table, "EFI stub: "msg); \ > diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c > index 8830fa6..94e7115 100644 > --- a/drivers/firmware/efi/libstub/fdt.c > +++ b/drivers/firmware/efi/libstub/fdt.c > @@ -323,6 +323,9 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, > if (status == EFI_SUCCESS) { > efi_set_virtual_address_map_t *svam; > > + if (novamap()) > + return EFI_SUCCESS; > + > /* Install the new virtual address map */ > svam = sys_table->runtime->set_virtual_address_map; > status = svam(runtime_entry_count * desc_size, desc_size, >
On Wed, Feb 20, 2019 at 03:51:34PM +0100, Paolo Pisati wrote: > From: Ard Biesheuvel <ard.biesheuvel@linaro.org> > > The UEFI spec revision 2.7 errata A section 8.4 has the following to > say about the virtual memory runtime services: > > "This section contains function definitions for the virtual memory > support that may be optionally used by an operating system at runtime. > If an operating system chooses to make EFI runtime service calls in a > virtual addressing mode instead of the flat physical mode, then the > operating system must use the services in this section to switch the > EFI runtime services from flat physical addressing to virtual > addressing." > > So it is pretty clear that calling SetVirtualAddressMap() is entirely > optional, and so there is no point in doing so unless it achieves > anything useful for us. > > This is not the case for 64-bit ARM. The identity mapping used by the > firmware is arbitrarily converted into another permutation of userland > addresses (i.e., bits [63:48] cleared), and the runtime code could easily > deal with the original layout in exactly the same way as it deals with > the converted layout. However, due to constraints related to page size > differences if the OS is not running with 4k pages, and related to > systems that may expose the individual sections of PE/COFF runtime > modules as different memory regions, creating the virtual layout is a > bit fiddly, and requires us to sort the memory map and reason about > adjacent regions with identical memory types etc etc. > > So the obvious fix is to stop calling SetVirtualAddressMap() altogether > on arm64 systems. However, to avoid surprises, which are notoriously > hard to diagnose when it comes to OS<->firmware interactions, let's > start by making it an opt-out feature, and implement support for the > 'efi=novamap' kernel command line parameter on ARM and arm64 systems. > > ( Note that 32-bit ARM generally does require SetVirtualAddressMap() to be > used, given that the physical memory map and the kernel virtual address > map are not guaranteed to be non-overlapping like on arm64. However, > having support for efi=novamap,noruntime on 32-bit ARM, combined with > the recently proposed support for earlycon=efifb, is likely to be useful > to diagnose boot issues on such systems if they have no accessible serial > port. ) > > Tested-by: Jeffrey Hugo <jhugo@codeaurora.org> > Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org> > Tested-by: Lee Jones <lee.jones@linaro.org> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> > Cc: Alexander Graf <agraf@suse.de> > Cc: Borislav Petkov <bp@alien8.de> > Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> > Cc: Leif Lindholm <leif.lindholm@linaro.org> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Cc: Matt Fleming <matt@codeblueprint.co.uk> > Cc: Peter Jones <pjones@redhat.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: linux-efi@vger.kernel.org > Link: http://lkml.kernel.org/r/20190202094119.13230-8-ard.biesheuvel@linaro.org > Signed-off-by: Ingo Molnar <mingo@kernel.org> > (cherry picked from commit 4e46c2a956215482418d7b315749fb1b6c6bc224) This commit doesn't appear to be in Linus' tree. Where did it come from?
https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=4e46c2a956215482418d7b315749fb1b6c6bc224 On Fri, Feb 22, 2019 at 11:09 AM Seth Forshee <seth.forshee@canonical.com> wrote: > > On Wed, Feb 20, 2019 at 03:51:34PM +0100, Paolo Pisati wrote: > > From: Ard Biesheuvel <ard.biesheuvel@linaro.org> > > > > The UEFI spec revision 2.7 errata A section 8.4 has the following to > > say about the virtual memory runtime services: > > > > "This section contains function definitions for the virtual memory > > support that may be optionally used by an operating system at runtime. > > If an operating system chooses to make EFI runtime service calls in a > > virtual addressing mode instead of the flat physical mode, then the > > operating system must use the services in this section to switch the > > EFI runtime services from flat physical addressing to virtual > > addressing." > > > > So it is pretty clear that calling SetVirtualAddressMap() is entirely > > optional, and so there is no point in doing so unless it achieves > > anything useful for us. > > > > This is not the case for 64-bit ARM. The identity mapping used by the > > firmware is arbitrarily converted into another permutation of userland > > addresses (i.e., bits [63:48] cleared), and the runtime code could easily > > deal with the original layout in exactly the same way as it deals with > > the converted layout. However, due to constraints related to page size > > differences if the OS is not running with 4k pages, and related to > > systems that may expose the individual sections of PE/COFF runtime > > modules as different memory regions, creating the virtual layout is a > > bit fiddly, and requires us to sort the memory map and reason about > > adjacent regions with identical memory types etc etc. > > > > So the obvious fix is to stop calling SetVirtualAddressMap() altogether > > on arm64 systems. However, to avoid surprises, which are notoriously > > hard to diagnose when it comes to OS<->firmware interactions, let's > > start by making it an opt-out feature, and implement support for the > > 'efi=novamap' kernel command line parameter on ARM and arm64 systems. > > > > ( Note that 32-bit ARM generally does require SetVirtualAddressMap() to be > > used, given that the physical memory map and the kernel virtual address > > map are not guaranteed to be non-overlapping like on arm64. However, > > having support for efi=novamap,noruntime on 32-bit ARM, combined with > > the recently proposed support for earlycon=efifb, is likely to be useful > > to diagnose boot issues on such systems if they have no accessible serial > > port. ) > > > > Tested-by: Jeffrey Hugo <jhugo@codeaurora.org> > > Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org> > > Tested-by: Lee Jones <lee.jones@linaro.org> > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > > Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> > > Cc: Alexander Graf <agraf@suse.de> > > Cc: Borislav Petkov <bp@alien8.de> > > Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> > > Cc: Leif Lindholm <leif.lindholm@linaro.org> > > Cc: Linus Torvalds <torvalds@linux-foundation.org> > > Cc: Matt Fleming <matt@codeblueprint.co.uk> > > Cc: Peter Jones <pjones@redhat.com> > > Cc: Peter Zijlstra <peterz@infradead.org> > > Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> > > Cc: Thomas Gleixner <tglx@linutronix.de> > > Cc: linux-efi@vger.kernel.org > > Link: http://lkml.kernel.org/r/20190202094119.13230-8-ard.biesheuvel@linaro.org > > Signed-off-by: Ingo Molnar <mingo@kernel.org> > > (cherry picked from commit 4e46c2a956215482418d7b315749fb1b6c6bc224) > > This commit doesn't appear to be in Linus' tree. Where did it come from? >
On Fri, Feb 22, 2019 at 11:29:19AM +0100, Paolo Pisati wrote: > https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=4e46c2a956215482418d7b315749fb1b6c6bc224 Ok, in the future you should include that information like this: (cherry picked from commit 4e46c2a956215482418d7b315749fb1b6c6bc224 https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git) Otherwise it is assumed the sha1 is from Linus' tree. > > On Fri, Feb 22, 2019 at 11:09 AM Seth Forshee > <seth.forshee@canonical.com> wrote: > > > > On Wed, Feb 20, 2019 at 03:51:34PM +0100, Paolo Pisati wrote: > > > From: Ard Biesheuvel <ard.biesheuvel@linaro.org> > > > > > > The UEFI spec revision 2.7 errata A section 8.4 has the following to > > > say about the virtual memory runtime services: > > > > > > "This section contains function definitions for the virtual memory > > > support that may be optionally used by an operating system at runtime. > > > If an operating system chooses to make EFI runtime service calls in a > > > virtual addressing mode instead of the flat physical mode, then the > > > operating system must use the services in this section to switch the > > > EFI runtime services from flat physical addressing to virtual > > > addressing." > > > > > > So it is pretty clear that calling SetVirtualAddressMap() is entirely > > > optional, and so there is no point in doing so unless it achieves > > > anything useful for us. > > > > > > This is not the case for 64-bit ARM. The identity mapping used by the > > > firmware is arbitrarily converted into another permutation of userland > > > addresses (i.e., bits [63:48] cleared), and the runtime code could easily > > > deal with the original layout in exactly the same way as it deals with > > > the converted layout. However, due to constraints related to page size > > > differences if the OS is not running with 4k pages, and related to > > > systems that may expose the individual sections of PE/COFF runtime > > > modules as different memory regions, creating the virtual layout is a > > > bit fiddly, and requires us to sort the memory map and reason about > > > adjacent regions with identical memory types etc etc. > > > > > > So the obvious fix is to stop calling SetVirtualAddressMap() altogether > > > on arm64 systems. However, to avoid surprises, which are notoriously > > > hard to diagnose when it comes to OS<->firmware interactions, let's > > > start by making it an opt-out feature, and implement support for the > > > 'efi=novamap' kernel command line parameter on ARM and arm64 systems. > > > > > > ( Note that 32-bit ARM generally does require SetVirtualAddressMap() to be > > > used, given that the physical memory map and the kernel virtual address > > > map are not guaranteed to be non-overlapping like on arm64. However, > > > having support for efi=novamap,noruntime on 32-bit ARM, combined with > > > the recently proposed support for earlycon=efifb, is likely to be useful > > > to diagnose boot issues on such systems if they have no accessible serial > > > port. ) > > > > > > Tested-by: Jeffrey Hugo <jhugo@codeaurora.org> > > > Tested-by: Bjorn Andersson <bjorn.andersson@linaro.org> > > > Tested-by: Lee Jones <lee.jones@linaro.org> > > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > > > Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> > > > Cc: Alexander Graf <agraf@suse.de> > > > Cc: Borislav Petkov <bp@alien8.de> > > > Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> > > > Cc: Leif Lindholm <leif.lindholm@linaro.org> > > > Cc: Linus Torvalds <torvalds@linux-foundation.org> > > > Cc: Matt Fleming <matt@codeblueprint.co.uk> > > > Cc: Peter Jones <pjones@redhat.com> > > > Cc: Peter Zijlstra <peterz@infradead.org> > > > Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> > > > Cc: Thomas Gleixner <tglx@linutronix.de> > > > Cc: linux-efi@vger.kernel.org > > > Link: http://lkml.kernel.org/r/20190202094119.13230-8-ard.biesheuvel@linaro.org > > > Signed-off-by: Ingo Molnar <mingo@kernel.org> > > > (cherry picked from commit 4e46c2a956215482418d7b315749fb1b6c6bc224) > > > > This commit doesn't appear to be in Linus' tree. Where did it come from? > > > > > -- > bye, > p.
diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c index 01a9d78..3b1e1dc 100644 --- a/drivers/firmware/efi/libstub/arm-stub.c +++ b/drivers/firmware/efi/libstub/arm-stub.c @@ -364,6 +364,11 @@ void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size, paddr = in->phys_addr; size = in->num_pages * EFI_PAGE_SIZE; + if (novamap()) { + in->virt_addr = in->phys_addr; + continue; + } + /* * Make the mapping compatible with 64k pages: this allows * a 4k page size kernel to kexec a 64k page size kernel and diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c index 50a9cab..39f87e6 100644 --- a/drivers/firmware/efi/libstub/efi-stub-helper.c +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -34,6 +34,7 @@ static unsigned long __chunk_size = EFI_READ_CHUNK_SIZE; static int __section(.data) __nokaslr; static int __section(.data) __quiet; +static int __section(.data) __novamap; int __pure nokaslr(void) { @@ -43,6 +44,10 @@ int __pure is_quiet(void) { return __quiet; } +int __pure novamap(void) +{ + return __novamap; +} #define EFI_MMAP_NR_SLACK_SLOTS 8 @@ -454,6 +459,11 @@ efi_status_t efi_parse_options(char const *cmdline) __chunk_size = -1UL; } + if (!strncmp(str, "novamap", 7)) { + str += strlen("novamap"); + __novamap = 1; + } + /* Group words together, delimited by "," */ while (*str && *str != ' ' && *str != ',') str++; diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index f59564b..2adde22 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -27,6 +27,7 @@ extern int __pure nokaslr(void); extern int __pure is_quiet(void); +extern int __pure novamap(void); #define pr_efi(sys_table, msg) do { \ if (!is_quiet()) efi_printk(sys_table, "EFI stub: "msg); \ diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c index 8830fa6..94e7115 100644 --- a/drivers/firmware/efi/libstub/fdt.c +++ b/drivers/firmware/efi/libstub/fdt.c @@ -323,6 +323,9 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table, if (status == EFI_SUCCESS) { efi_set_virtual_address_map_t *svam; + if (novamap()) + return EFI_SUCCESS; + /* Install the new virtual address map */ svam = sys_table->runtime->set_virtual_address_map; status = svam(runtime_entry_count * desc_size, desc_size,