| Message ID | 20181221115446.2670-1-ard.biesheuvel@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [efi-urgent] Revert "efi: Align 'efi_guid_t' to 64 bits" | expand |
On Fri, Dec 21, 2018 at 12:54:46PM +0100, Ard Biesheuvel wrote: > This reverts commit 793423cf07e51e3185b8680167115813589c057d. > > The 64-bit alignment affects the size of efi_config_table_32_t, > which is used as an array type. On the other hand, the former > byte alignment could trigger alignment faults during firmware > calls on 32-bit ARM, since UEFI defines efi_guid_t as a struct > of UINT32 + UINT16 + UINT16 + UINT8[8], and so it may use load/ > store multiple instructions [requiring 32-bit alignment], e.g., > on GUID pointers passed as function arguments since UEFI's view > of the type has implicit 32-bit alignment. > > Let's sort this out for the next release, and revert the change > for now. > > Fixes: 793423cf07e5 ("efi: Align 'efi_guid_t' to 64 bits") > Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de> > Cc: Ingo Molnar <mingo@kernel.org> > Cc: Andy Lutomirski <luto@kernel.org> > Cc: Borislav Petkov <bp@alien8.de> > Cc: Dave Hansen <dave.hansen@linux.intel.com> > Cc: H. Peter Anvin <hpa@zytor.com> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Qian Cai <cai@gmx.us> > Cc: Rik van Riel <riel@surriel.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > include/linux/efi.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/efi.h b/include/linux/efi.h > index e6480c805932..100ce4a4aff6 100644 > --- a/include/linux/efi.h > +++ b/include/linux/efi.h > @@ -48,7 +48,7 @@ typedef u16 efi_char16_t; /* UNICODE character */ > typedef u64 efi_physical_addr_t; > typedef void *efi_handle_t; > > -typedef guid_t efi_guid_t __aligned(8); > +typedef guid_t efi_guid_t; > > #define EFI_GUID(a,b,c,d0,d1,d2,d3,d4,d5,d6,d7) \ > GUID_INIT(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7) > -- It was the top commit on tip:efi/urgent so I've zapped it. HTH. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.
On Fri, 21 Dec 2018 at 13:13, Borislav Petkov <bp@alien8.de> wrote: > > On Fri, Dec 21, 2018 at 12:54:46PM +0100, Ard Biesheuvel wrote: > > This reverts commit 793423cf07e51e3185b8680167115813589c057d. > > > > The 64-bit alignment affects the size of efi_config_table_32_t, > > which is used as an array type. On the other hand, the former > > byte alignment could trigger alignment faults during firmware > > calls on 32-bit ARM, since UEFI defines efi_guid_t as a struct > > of UINT32 + UINT16 + UINT16 + UINT8[8], and so it may use load/ > > store multiple instructions [requiring 32-bit alignment], e.g., > > on GUID pointers passed as function arguments since UEFI's view > > of the type has implicit 32-bit alignment. > > > > Let's sort this out for the next release, and revert the change > > for now. > > > > Fixes: 793423cf07e5 ("efi: Align 'efi_guid_t' to 64 bits") > > Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de> > > Cc: Ingo Molnar <mingo@kernel.org> > > Cc: Andy Lutomirski <luto@kernel.org> > > Cc: Borislav Petkov <bp@alien8.de> > > Cc: Dave Hansen <dave.hansen@linux.intel.com> > > Cc: H. Peter Anvin <hpa@zytor.com> > > Cc: Linus Torvalds <torvalds@linux-foundation.org> > > Cc: Peter Zijlstra <peterz@infradead.org> > > Cc: Qian Cai <cai@gmx.us> > > Cc: Rik van Riel <riel@surriel.com> > > Cc: Thomas Gleixner <tglx@linutronix.de> > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > > --- > > include/linux/efi.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/include/linux/efi.h b/include/linux/efi.h > > index e6480c805932..100ce4a4aff6 100644 > > --- a/include/linux/efi.h > > +++ b/include/linux/efi.h > > @@ -48,7 +48,7 @@ typedef u16 efi_char16_t; /* UNICODE character */ > > typedef u64 efi_physical_addr_t; > > typedef void *efi_handle_t; > > > > -typedef guid_t efi_guid_t __aligned(8); > > +typedef guid_t efi_guid_t; > > > > #define EFI_GUID(a,b,c,d0,d1,d2,d3,d4,d5,d6,d7) \ > > GUID_INIT(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7) > > -- > > It was the top commit on tip:efi/urgent so I've zapped it. > Even better! Thanks a lot
diff --git a/include/linux/efi.h b/include/linux/efi.h index e6480c805932..100ce4a4aff6 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -48,7 +48,7 @@ typedef u16 efi_char16_t; /* UNICODE character */ typedef u64 efi_physical_addr_t; typedef void *efi_handle_t; -typedef guid_t efi_guid_t __aligned(8); +typedef guid_t efi_guid_t; #define EFI_GUID(a,b,c,d0,d1,d2,d3,d4,d5,d6,d7) \ GUID_INIT(a, b, c, d0, d1, d2, d3, d4, d5, d6, d7)
This reverts commit 793423cf07e51e3185b8680167115813589c057d. The 64-bit alignment affects the size of efi_config_table_32_t, which is used as an array type. On the other hand, the former byte alignment could trigger alignment faults during firmware calls on 32-bit ARM, since UEFI defines efi_guid_t as a struct of UINT32 + UINT16 + UINT16 + UINT8[8], and so it may use load/ store multiple instructions [requiring 32-bit alignment], e.g., on GUID pointers passed as function arguments since UEFI's view of the type has implicit 32-bit alignment. Let's sort this out for the next release, and revert the change for now. Fixes: 793423cf07e5 ("efi: Align 'efi_guid_t' to 64 bits") Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qian Cai <cai@gmx.us> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- include/linux/efi.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.19.2