AsciiStrCat() is deprecated / disabled under the DISABLE_NEW_DEPRECATED_INTERFACES feature test macro.
The caller of CpsrString() is required to pass in "ReturnStr" with 32 CHAR8 elements. (DefaultExceptionHandler() complies with this.) "Str" is used to build "ReturnStr" gradually. Just before calling AsciiStrCat(), "Str" points to the then-terminating NUL character in "ReturnStr". The difference (Str - ReturnStr) gives the number of non-NUL characters we've written thus far, hence (32 - (Str - ReturnStr)) yields the number of remaining bytes in ReturnStr, including the ultimately terminating NUL character. Cc: Ard Biesheuvel <[email protected]> Cc: Leif Lindholm <[email protected]> Cc: Michael Zimmermann <[email protected]> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=164 Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=165 Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Laszlo Ersek <[email protected]> --- Notes: - build-tested only - Michael (CC'd) had posted a patch earlier for this: <https://lists.01.org/pipermail/edk2-devel/2016-August/000489.html>, but I only noticed that now that he pointed it out, in <https://lists.01.org/pipermail/edk2-devel/2016-October/003121.html>. I'll leave it to the ArmPkg maintainers to choose one; I don't feel strongly either way. ArmPkg/Library/DefaultExceptionHandlerLib/Arm/DefaultExceptionHandler.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/ArmPkg/Library/DefaultExceptionHandlerLib/Arm/DefaultExceptionHandler.c b/ArmPkg/Library/DefaultExceptionHandlerLib/Arm/DefaultExceptionHandler.c index aece26355e2e..4b2ee9a9acf7 100644 --- a/ArmPkg/Library/DefaultExceptionHandlerLib/Arm/DefaultExceptionHandler.c +++ b/ArmPkg/Library/DefaultExceptionHandlerLib/Arm/DefaultExceptionHandler.c @@ -116,7 +116,10 @@ CpsrString ( break; } - AsciiStrCat (Str, ModeStr); + // + // See the interface contract in the leading comment block. + // + AsciiStrCatS (Str, 32 - (Str - ReturnStr), ModeStr); return; } -- 2.9.2 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
