| Message ID | 1478197093-17209-1-git-send-email-ard.biesheuvel@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 11/03/16 19:18, Ard Biesheuvel wrote: > Unlike other string functions in this library, ZeroMem () does not > return early when the length of the input buffer is 0. So add the > same to ZeroMem () as well. > > This fixes an issue with the ARM implementation, whose InternalMemZeroMem > code does not expect a length of 0, and always writes at least a single > byte. > > Contributed-under: TianoCore Contribution Agreement 1.0 > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > MdePkg/Library/BaseMemoryLibOptDxe/ZeroMemWrapper.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/MdePkg/Library/BaseMemoryLibOptDxe/ZeroMemWrapper.c b/MdePkg/Library/BaseMemoryLibOptDxe/ZeroMemWrapper.c > index 2a0a038fd6c5..9dd0b45e188e 100644 > --- a/MdePkg/Library/BaseMemoryLibOptDxe/ZeroMemWrapper.c > +++ b/MdePkg/Library/BaseMemoryLibOptDxe/ZeroMemWrapper.c > @@ -46,7 +46,11 @@ ZeroMem ( > IN UINTN Length > ) > { > - ASSERT (!(Buffer == NULL && Length > 0)); > + if (Length == 0) { > + return Buffer; > + } > + > + ASSERT (Buffer != NULL); > ASSERT (Length <= (MAX_ADDRESS - (UINTN)Buffer + 1)); > return InternalMemZeroMem (Buffer, Length); > } > Assuming the ARM impl of InternalMemZeroMem() conforms to the InternalMemZeroMem() contract -- if there is such a contract --, I think this patch makes sense: Acked-by: Laszlo Ersek <lersek@redhat.com> Thanks Laszlo _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
Ard: Could you help apply this changes for other BaseMemoryLib instances in MdePkg? Thanks Liming > -----Original Message----- > From: Ard Biesheuvel [mailto:ard.biesheuvel@linaro.org] > Sent: Friday, November 04, 2016 2:18 AM > To: edk2-devel@lists.01.org; Kinney, Michael D > <michael.d.kinney@intel.com>; Gao, Liming <liming.gao@intel.com> > Cc: lersek@redhat.com; Carsey, Jaben <jaben.carsey@intel.com>; Ard > Biesheuvel <ard.biesheuvel@linaro.org> > Subject: [PATCH v2] MdePkg/BaseMemoryLibOptDxe: check for zero length > in ZeroMem () > > Unlike other string functions in this library, ZeroMem () does not > return early when the length of the input buffer is 0. So add the > same to ZeroMem () as well. > > This fixes an issue with the ARM implementation, whose > InternalMemZeroMem > code does not expect a length of 0, and always writes at least a single > byte. > > Contributed-under: TianoCore Contribution Agreement 1.0 > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> > --- > MdePkg/Library/BaseMemoryLibOptDxe/ZeroMemWrapper.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/MdePkg/Library/BaseMemoryLibOptDxe/ZeroMemWrapper.c > b/MdePkg/Library/BaseMemoryLibOptDxe/ZeroMemWrapper.c > index 2a0a038fd6c5..9dd0b45e188e 100644 > --- a/MdePkg/Library/BaseMemoryLibOptDxe/ZeroMemWrapper.c > +++ b/MdePkg/Library/BaseMemoryLibOptDxe/ZeroMemWrapper.c > @@ -46,7 +46,11 @@ ZeroMem ( > IN UINTN Length > ) > { > - ASSERT (!(Buffer == NULL && Length > 0)); > + if (Length == 0) { > + return Buffer; > + } > + > + ASSERT (Buffer != NULL); > ASSERT (Length <= (MAX_ADDRESS - (UINTN)Buffer + 1)); > return InternalMemZeroMem (Buffer, Length); > } > -- > 2.7.4 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
diff --git a/MdePkg/Library/BaseMemoryLibOptDxe/ZeroMemWrapper.c b/MdePkg/Library/BaseMemoryLibOptDxe/ZeroMemWrapper.c index 2a0a038fd6c5..9dd0b45e188e 100644 --- a/MdePkg/Library/BaseMemoryLibOptDxe/ZeroMemWrapper.c +++ b/MdePkg/Library/BaseMemoryLibOptDxe/ZeroMemWrapper.c @@ -46,7 +46,11 @@ ZeroMem ( IN UINTN Length ) { - ASSERT (!(Buffer == NULL && Length > 0)); + if (Length == 0) { + return Buffer; + } + + ASSERT (Buffer != NULL); ASSERT (Length <= (MAX_ADDRESS - (UINTN)Buffer + 1)); return InternalMemZeroMem (Buffer, Length); }
Unlike other string functions in this library, ZeroMem () does not return early when the length of the input buffer is 0. So add the same to ZeroMem () as well. This fixes an issue with the ARM implementation, whose InternalMemZeroMem code does not expect a length of 0, and always writes at least a single byte. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- MdePkg/Library/BaseMemoryLibOptDxe/ZeroMemWrapper.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) -- 2.7.4 _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel