On 02/03/20 10:09, Zeng, Star wrote: >> -----Original Message----- >> From: Laszlo Ersek <[email protected]> >> Sent: Monday, February 3, 2020 4:47 PM >> To: Zeng, Star <[email protected]>; [email protected] >> Cc: Dong, Eric <[email protected]>; Ni, Ray <[email protected]> >> Subject: Re: [PATCH] UefiCpuPkg RegisterCpuFeaturesLib: Use %08x to print >> CacheControl Index >> >> Hello Star, >> >> On 02/03/20 08:06, Star Zeng wrote: >>> Instead of %08lx, use %08x to print CacheControl Index as it is UINT32 >>> type. >>> >>> Cc: Eric Dong <[email protected]> >>> Cc: Ray Ni <[email protected]> >>> Cc: Laszlo Ersek <[email protected]> >>> Signed-off-by: Star Zeng <[email protected]> >>> --- >>> .../Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git >>> a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c >>> b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c >>> index 0a4fcff033a3..1a02809b0e7c 100644 >>> --- >>> a/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize.c >>> +++ b/UefiCpuPkg/Library/RegisterCpuFeaturesLib/CpuFeaturesInitialize. >>> +++ c >>> @@ -465,7 +465,7 @@ DumpRegisterTableOnProcessor ( >>> case CacheControl: >>> DEBUG (( >>> DebugPrintErrorLevel, >>> - "Processor: %04d: Index %04d, CACHE: %08lx, Bit Start: %02d, >> Bit Length: %02d, Value: %016lx\r\n", >>> + "Processor: %04d: Index %04d, CACHE: %08x, Bit Start: %02d, >>> + Bit Length: %02d, Value: %016lx\r\n", >>> ProcessorNumber, >>> FeatureIndex, >>> RegisterTableEntry->Index, >>> >> >> if you are already touching this DEBUG invocation, can you please fix the >> rest of the issues with the format string? >> >> - ProcessorNumber is UINTN. If we know for sure it can be represented in a >> UINT32, then it should be cast to UINT32 explicitly, and logged with "%04u". >> (Otherwise, UINTN needs to be cast to UINT64, and logged with %lu or %lx.) >> >> - Ditto for FeatureIndex. > > %04u or %04d is not enough for UINT32 which needs %08x. > I thought the code is just taking assumption about their value should be not > > 9999u. It is not a real issue.
I disagree. It's not about the field width / padding (4 vs. 8 characters), but the width of the data type. The parameter that's being passed is a UINTN, which is UINT64 on X64. But the format specifier (%d, %u, %x all alike) only expect a UINT32. If we pass a UINT64 (in the form of a UINTN), then we should print it with a UINT64 specifier (such as %lu or %lx). Alternatively, if we know for sure that the value of the UINT64 in question will fit in a UINT32, then we can use %u or %x for printing, but then we need to truncate (cast) the data that's being passed in, to UINT32. My point is that the data size should be a match between what's passed in and what is described with a format specifier. There is no format specifier that directly matches UINTN, so you either need to cast UINTN to UINT64 and use %lx, or cast UINTN to UINT32 and use %x. > > This patch is to fix a real issue, without it, the print for ValidBitStart, > ValidBitLength and Value will be wrong because the parameter for them are > shifted for Index to fetch UINT64 value. The patch is not wrong, it's just incomplete (given that we're modifying a format string that mismatches the argument list in other places too). ProcessorNumber and FeatureIndex are UINTNs, and they are being printed with %d. Those are real issues too. > I found another real issue is MMIO : %08lx should be MMIO : %016lx as the > code is on purpose to get UINT64 MMIO address. Field width / padding are useful to get right, but getting the data types to match is even more important. Thanks Laszlo > I prefer to just handle the real issue in this patch. How do you think? 😊 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#53663): https://edk2.groups.io/g/devel/message/53663 Mute This Topic: https://groups.io/mt/70940928/21656 Group Owner: [email protected] Unsubscribe: https://edk2.groups.io/g/devel/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
