| Message ID | 1490088209-8564-2-git-send-email-ard.biesheuvel@linaro.org |
|---|---|
| State | Accepted |
| Commit | 60bd1e1269ff93390a90014144a835ad71fe2fa0 |
| Headers | show |
| Series | ArmVirtPkg/HighMemDxe: fix issues reported by Michael | expand |
On 03/21/17 10:23, Ard Biesheuvel wrote: > Instead of invoking gDS->SetMemorySpaceAttributes to set the EFI_MEMORY_XP > attribute on newly added regions, which is guaranteed to fail if the same > attribute was not declared as a capability of the region when it as added, > invoke the CPU arch protocol directly to set the EFI_MEMORY_XP attribute > if our memory protection policy demands it. > > Reported-by: Michael Zimmermann <sigmaepsilon92@gmail.com> > Contributed-under: TianoCore Contribution Agreement 1.0 > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > ArmVirtPkg/HighMemDxe/HighMemDxe.c | 31 +++++++++++++++----- > ArmVirtPkg/HighMemDxe/HighMemDxe.inf | 1 + > 2 files changed, 25 insertions(+), 7 deletions(-) > > diff --git a/ArmVirtPkg/HighMemDxe/HighMemDxe.c b/ArmVirtPkg/HighMemDxe/HighMemDxe.c > index f70978f6414f..4e41120deff3 100644 > --- a/ArmVirtPkg/HighMemDxe/HighMemDxe.c > +++ b/ArmVirtPkg/HighMemDxe/HighMemDxe.c > @@ -20,6 +20,7 @@ > #include <Library/PcdLib.h> > #include <Library/UefiBootServicesTableLib.h> > > +#include <Protocol/Cpu.h> > #include <Protocol/FdtClient.h> > > EFI_STATUS > @@ -30,6 +31,7 @@ InitializeHighMemDxe ( > ) > { > FDT_CLIENT_PROTOCOL *FdtClient; > + EFI_CPU_ARCH_PROTOCOL *Cpu; > EFI_STATUS Status, FindNodeStatus; > INT32 Node; > CONST UINT32 *Reg; > @@ -43,6 +45,10 @@ InitializeHighMemDxe ( > (VOID **)&FdtClient); > ASSERT_EFI_ERROR (Status); > > + Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, > + (VOID **)&Cpu); > + ASSERT_EFI_ERROR (Status); > + > // > // Check for memory node and add the memory spaces except the lowest one > // > @@ -78,13 +84,24 @@ InitializeHighMemDxe ( > continue; > } > > + Status = gDS->SetMemorySpaceAttributes (CurBase, CurSize, > + EFI_MEMORY_WB); > + if (EFI_ERROR (Status)) { > + DEBUG ((DEBUG_WARN, > + "%a: gDS->SetMemorySpaceAttributes() failed on region 0x%lx - 0x%lx (%r)\n", > + __FUNCTION__, CurBase, CurBase + CurSize - 1, Status)); > + } > + > + // > + // Due to the ambiguous nature of the RO/XP GCD memory space attributes, > + // it is impossible to add a memory space with the XP attribute in a way > + // that does not result in the XP attribute being set on *all* UEFI > + // memory map entries that are carved from it, including code regions > + // that require executable permissions. > // > - // Take care not to strip any permission attributes that will have been > - // set by DxeCore on the region we just added if a strict permission > - // policy is in effect for EfiConventionalMemory regions. > - // Unfortunately, we cannot interrogate the GCD memory space map for > - // those permissions, since they are not recorded there (for historical > - // reasons), so check the policy directly. > + // So instead, we never set the RO/XP attributes in the GCD memory space > + // capabilities or attribute fields, and apply any protections directly > + // on the page table mappings by going through the cpu arch protocol. > // > Attributes = EFI_MEMORY_WB; > if ((PcdGet64 (PcdDxeNxMemoryProtectionPolicy) & > @@ -92,7 +109,7 @@ InitializeHighMemDxe ( > Attributes |= EFI_MEMORY_XP; > } > > - Status = gDS->SetMemorySpaceAttributes (CurBase, CurSize, Attributes); > + Status = Cpu->SetMemoryAttributes (Cpu, CurBase, CurSize, Attributes); > > if (EFI_ERROR (Status)) { > DEBUG ((EFI_D_ERROR, > diff --git a/ArmVirtPkg/HighMemDxe/HighMemDxe.inf b/ArmVirtPkg/HighMemDxe/HighMemDxe.inf > index 89c743ebe058..ac1761974f52 100644 > --- a/ArmVirtPkg/HighMemDxe/HighMemDxe.inf > +++ b/ArmVirtPkg/HighMemDxe/HighMemDxe.inf > @@ -41,6 +41,7 @@ [LibraryClasses] > UefiDriverEntryPoint > > [Protocols] > + gEfiCpuArchProtocolGuid ## CONSUMES > gFdtClientProtocolGuid ## CONSUMES > > [Pcd] > gEfiCpuArchProtocolGuid is already part of the DEPEX, so: Reviewed-by: Laszlo Ersek <lersek@redhat.com> _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
diff --git a/ArmVirtPkg/HighMemDxe/HighMemDxe.c b/ArmVirtPkg/HighMemDxe/HighMemDxe.c index f70978f6414f..4e41120deff3 100644 --- a/ArmVirtPkg/HighMemDxe/HighMemDxe.c +++ b/ArmVirtPkg/HighMemDxe/HighMemDxe.c @@ -20,6 +20,7 @@ #include <Library/PcdLib.h> #include <Library/UefiBootServicesTableLib.h> +#include <Protocol/Cpu.h> #include <Protocol/FdtClient.h> EFI_STATUS @@ -30,6 +31,7 @@ InitializeHighMemDxe ( ) { FDT_CLIENT_PROTOCOL *FdtClient; + EFI_CPU_ARCH_PROTOCOL *Cpu; EFI_STATUS Status, FindNodeStatus; INT32 Node; CONST UINT32 *Reg; @@ -43,6 +45,10 @@ InitializeHighMemDxe ( (VOID **)&FdtClient); ASSERT_EFI_ERROR (Status); + Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, + (VOID **)&Cpu); + ASSERT_EFI_ERROR (Status); + // // Check for memory node and add the memory spaces except the lowest one // @@ -78,13 +84,24 @@ InitializeHighMemDxe ( continue; } + Status = gDS->SetMemorySpaceAttributes (CurBase, CurSize, + EFI_MEMORY_WB); + if (EFI_ERROR (Status)) { + DEBUG ((DEBUG_WARN, + "%a: gDS->SetMemorySpaceAttributes() failed on region 0x%lx - 0x%lx (%r)\n", + __FUNCTION__, CurBase, CurBase + CurSize - 1, Status)); + } + + // + // Due to the ambiguous nature of the RO/XP GCD memory space attributes, + // it is impossible to add a memory space with the XP attribute in a way + // that does not result in the XP attribute being set on *all* UEFI + // memory map entries that are carved from it, including code regions + // that require executable permissions. // - // Take care not to strip any permission attributes that will have been - // set by DxeCore on the region we just added if a strict permission - // policy is in effect for EfiConventionalMemory regions. - // Unfortunately, we cannot interrogate the GCD memory space map for - // those permissions, since they are not recorded there (for historical - // reasons), so check the policy directly. + // So instead, we never set the RO/XP attributes in the GCD memory space + // capabilities or attribute fields, and apply any protections directly + // on the page table mappings by going through the cpu arch protocol. // Attributes = EFI_MEMORY_WB; if ((PcdGet64 (PcdDxeNxMemoryProtectionPolicy) & @@ -92,7 +109,7 @@ InitializeHighMemDxe ( Attributes |= EFI_MEMORY_XP; } - Status = gDS->SetMemorySpaceAttributes (CurBase, CurSize, Attributes); + Status = Cpu->SetMemoryAttributes (Cpu, CurBase, CurSize, Attributes); if (EFI_ERROR (Status)) { DEBUG ((EFI_D_ERROR, diff --git a/ArmVirtPkg/HighMemDxe/HighMemDxe.inf b/ArmVirtPkg/HighMemDxe/HighMemDxe.inf index 89c743ebe058..ac1761974f52 100644 --- a/ArmVirtPkg/HighMemDxe/HighMemDxe.inf +++ b/ArmVirtPkg/HighMemDxe/HighMemDxe.inf @@ -41,6 +41,7 @@ [LibraryClasses] UefiDriverEntryPoint [Protocols] + gEfiCpuArchProtocolGuid ## CONSUMES gFdtClientProtocolGuid ## CONSUMES [Pcd]
Instead of invoking gDS->SetMemorySpaceAttributes to set the EFI_MEMORY_XP attribute on newly added regions, which is guaranteed to fail if the same attribute was not declared as a capability of the region when it as added, invoke the CPU arch protocol directly to set the EFI_MEMORY_XP attribute if our memory protection policy demands it. Reported-by: Michael Zimmermann <sigmaepsilon92@gmail.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- ArmVirtPkg/HighMemDxe/HighMemDxe.c | 31 +++++++++++++++----- ArmVirtPkg/HighMemDxe/HighMemDxe.inf | 1 + 2 files changed, 25 insertions(+), 7 deletions(-) -- 2.7.4 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel