* [PATCH] UefiCpuPkg/CpuMpPei: suppress compiler complaining @ 2018-09-11 4:47 Jian J Wang 2018-09-11 14:55 ` Laszlo Ersek 0 siblings, 1 reply; 3+ messages in thread From: Jian J Wang @ 2018-09-11 4:47 UTC (permalink / raw) To: edk2-devel; +Cc: Dandan Bi, Hao A Wu BZ#: https://bugzilla.tianocore.org/show_bug.cgi?id=1166 Cc: Dandan Bi <dandan.bi@intel.com> Cc: Hao A Wu <hao.a.wu@intel.com> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Jian J Wang <jian.j.wang@intel.com> --- UefiCpuPkg/CpuMpPei/CpuPaging.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/UefiCpuPkg/CpuMpPei/CpuPaging.c b/UefiCpuPkg/CpuMpPei/CpuPaging.c index bcb942a8e5..a63421a1af 100644 --- a/UefiCpuPkg/CpuMpPei/CpuPaging.c +++ b/UefiCpuPkg/CpuMpPei/CpuPaging.c @@ -517,7 +517,7 @@ GetStackBase ( IN OUT VOID *Buffer ) { - EFI_PHYSICAL_ADDRESS StackBase; + volatile EFI_PHYSICAL_ADDRESS StackBase; StackBase = (EFI_PHYSICAL_ADDRESS)(UINTN)&StackBase; StackBase += BASE_4KB; @@ -554,6 +554,8 @@ SetupStackGuardPage ( MpInitLibGetNumberOfProcessors(&NumberOfProcessors, NULL); MpInitLibWhoAmI (&Bsp); for (Index = 0; Index < NumberOfProcessors; ++Index) { + StackBase = 0; + if (Index == Bsp) { Hob.Raw = GetHobList (); while ((Hob.Raw = GetNextHob (EFI_HOB_TYPE_MEMORY_ALLOCATION, Hob.Raw)) != NULL) { @@ -570,12 +572,19 @@ SetupStackGuardPage ( // MpInitLibStartupThisAP(GetStackBase, Index, NULL, 0, (VOID *)&StackBase, NULL); } - // - // Set Guard page at stack base address. - // - ConvertMemoryPageAttributes(StackBase, EFI_PAGE_SIZE, 0); - DEBUG ((DEBUG_INFO, "Stack Guard set at %lx [cpu%lu]!\n", - (UINT64)StackBase, (UINT64)Index)); + + if (StackBase == 0) { + DEBUG ((DEBUG_ERROR, "Stack base address was not found for [cpu%lu]!\n", + (UINT64)Index)); + ASSERT(StackBase != 0); + } else { + // + // Set Guard page at stack base address. + // + ConvertMemoryPageAttributes(StackBase, EFI_PAGE_SIZE, 0); + DEBUG ((DEBUG_INFO, "Stack Guard set at %lx [cpu%lu]!\n", + (UINT64)StackBase, (UINT64)Index)); + } } // -- 2.16.2.windows.1 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] UefiCpuPkg/CpuMpPei: suppress compiler complaining 2018-09-11 4:47 [PATCH] UefiCpuPkg/CpuMpPei: suppress compiler complaining Jian J Wang @ 2018-09-11 14:55 ` Laszlo Ersek 2018-09-12 0:23 ` Wang, Jian J 0 siblings, 1 reply; 3+ messages in thread From: Laszlo Ersek @ 2018-09-11 14:55 UTC (permalink / raw) To: Jian J Wang, edk2-devel; +Cc: Hao A Wu, Dandan Bi, Eric Dong Jian, On 09/11/18 06:47, Jian J Wang wrote: > BZ#: https://bugzilla.tianocore.org/show_bug.cgi?id=1166 > > Cc: Dandan Bi <dandan.bi@intel.com> > Cc: Hao A Wu <hao.a.wu@intel.com> > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Jian J Wang <jian.j.wang@intel.com> > --- > UefiCpuPkg/CpuMpPei/CpuPaging.c | 23 ++++++++++++++++------- > 1 file changed, 16 insertions(+), 7 deletions(-) (1) Please remember to CC the package maintainers / reviewers on patches. "Maintainers.txt" lists Eric (M) and myself (R) for UefiCpuPkg. It's OK to CC other people as well, of course. (2) Bug 1166 mentions "warning C4701: potentially uninitialized local variable 'StackBase' used". If that warning is invalid (= the variable can never be read unassigned), then we have some suggested language for that; please see <https://bugzilla.tianocore.org/show_bug.cgi?id=607>. Furthermore: > > diff --git a/UefiCpuPkg/CpuMpPei/CpuPaging.c b/UefiCpuPkg/CpuMpPei/CpuPaging.c > index bcb942a8e5..a63421a1af 100644 > --- a/UefiCpuPkg/CpuMpPei/CpuPaging.c > +++ b/UefiCpuPkg/CpuMpPei/CpuPaging.c > @@ -517,7 +517,7 @@ GetStackBase ( > IN OUT VOID *Buffer > ) > { > - EFI_PHYSICAL_ADDRESS StackBase; > + volatile EFI_PHYSICAL_ADDRESS StackBase; (3) "volatile" seems unrelated; I suggest dropping it. (Especially without the comment mentioned in TianoCore#607, "volatile" is totally unjustified and confusing.) > > StackBase = (EFI_PHYSICAL_ADDRESS)(UINTN)&StackBase; > StackBase += BASE_4KB; > @@ -554,6 +554,8 @@ SetupStackGuardPage ( > MpInitLibGetNumberOfProcessors(&NumberOfProcessors, NULL); > MpInitLibWhoAmI (&Bsp); > for (Index = 0; Index < NumberOfProcessors; ++Index) { > + StackBase = 0; > + > if (Index == Bsp) { > Hob.Raw = GetHobList (); > while ((Hob.Raw = GetNextHob (EFI_HOB_TYPE_MEMORY_ALLOCATION, Hob.Raw)) != NULL) { > @@ -570,12 +572,19 @@ SetupStackGuardPage ( > // > MpInitLibStartupThisAP(GetStackBase, Index, NULL, 0, (VOID *)&StackBase, NULL); > } > - // > - // Set Guard page at stack base address. > - // > - ConvertMemoryPageAttributes(StackBase, EFI_PAGE_SIZE, 0); > - DEBUG ((DEBUG_INFO, "Stack Guard set at %lx [cpu%lu]!\n", > - (UINT64)StackBase, (UINT64)Index)); > + > + if (StackBase == 0) { > + DEBUG ((DEBUG_ERROR, "Stack base address was not found for [cpu%lu]!\n", > + (UINT64)Index)); > + ASSERT(StackBase != 0); (4) On the other hand, if it *can* happen in practice that the stack base is not found (and in that case, we should halt), then: * the subject line is wrong, because the compiler warning is *valid*, and we don't suppress it, but fix the issue caught by the compiler; * we must not proceed in a RELEASE build either, therefore an ASSERT is insufficient. A CpuDeadLoop() is necessary. (Again, this only applies if StackBase may be zero here by design.) Thanks Laszlo > + } else { > + // > + // Set Guard page at stack base address. > + // > + ConvertMemoryPageAttributes(StackBase, EFI_PAGE_SIZE, 0); > + DEBUG ((DEBUG_INFO, "Stack Guard set at %lx [cpu%lu]!\n", > + (UINT64)StackBase, (UINT64)Index)); > + } > } > > // > ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] UefiCpuPkg/CpuMpPei: suppress compiler complaining 2018-09-11 14:55 ` Laszlo Ersek @ 2018-09-12 0:23 ` Wang, Jian J 0 siblings, 0 replies; 3+ messages in thread From: Wang, Jian J @ 2018-09-12 0:23 UTC (permalink / raw) To: Laszlo Ersek, edk2-devel@lists.01.org; +Cc: Wu, Hao A, Bi, Dandan, Dong, Eric Laszlo, Thanks for the comments. (1) Sure. My fault. I thought it’s just very small change for compiler warning. (2) From language point view, it’s a valid warning. But from code logic, it’s invalid. (3) Agree. It’ll be dropped. (4) Agree. I’ll change it. Regards, Jian From: Laszlo Ersek [mailto:lersek@redhat.com] Sent: Tuesday, September 11, 2018 10:56 PM To: Wang, Jian J <jian.j.wang@intel.com>; edk2-devel@lists.01.org Cc: Wu, Hao A <hao.a.wu@intel.com>; Bi, Dandan <dandan.bi@intel.com>; Dong, Eric <eric.dong@intel.com> Subject: Re: [edk2] [PATCH] UefiCpuPkg/CpuMpPei: suppress compiler complaining Jian, On 09/11/18 06:47, Jian J Wang wrote: > BZ#: https://bugzilla.tianocore.org/show_bug.cgi?id=1166 > > Cc: Dandan Bi <dandan.bi@intel.com<mailto:dandan.bi@intel.com>> > Cc: Hao A Wu <hao.a.wu@intel.com<mailto:hao.a.wu@intel.com>> > Contributed-under: TianoCore Contribution Agreement 1.1 > Signed-off-by: Jian J Wang <jian.j.wang@intel.com<mailto:jian.j.wang@intel.com>> > --- > UefiCpuPkg/CpuMpPei/CpuPaging.c | 23 ++++++++++++++++------- > 1 file changed, 16 insertions(+), 7 deletions(-) (1) Please remember to CC the package maintainers / reviewers on patches. "Maintainers.txt" lists Eric (M) and myself (R) for UefiCpuPkg. It's OK to CC other people as well, of course. (2) Bug 1166 mentions "warning C4701: potentially uninitialized local variable 'StackBase' used". If that warning is invalid (= the variable can never be read unassigned), then we have some suggested language for that; please see <https://bugzilla.tianocore.org/show_bug.cgi?id=607>. Furthermore: > > diff --git a/UefiCpuPkg/CpuMpPei/CpuPaging.c b/UefiCpuPkg/CpuMpPei/CpuPaging.c > index bcb942a8e5..a63421a1af 100644 > --- a/UefiCpuPkg/CpuMpPei/CpuPaging.c > +++ b/UefiCpuPkg/CpuMpPei/CpuPaging.c > @@ -517,7 +517,7 @@ GetStackBase ( > IN OUT VOID *Buffer > ) > { > - EFI_PHYSICAL_ADDRESS StackBase; > + volatile EFI_PHYSICAL_ADDRESS StackBase; (3) "volatile" seems unrelated; I suggest dropping it. (Especially without the comment mentioned in TianoCore#607, "volatile" is totally unjustified and confusing.) > > StackBase = (EFI_PHYSICAL_ADDRESS)(UINTN)&StackBase; > StackBase += BASE_4KB; > @@ -554,6 +554,8 @@ SetupStackGuardPage ( > MpInitLibGetNumberOfProcessors(&NumberOfProcessors, NULL); > MpInitLibWhoAmI (&Bsp); > for (Index = 0; Index < NumberOfProcessors; ++Index) { > + StackBase = 0; > + > if (Index == Bsp) { > Hob.Raw = GetHobList (); > while ((Hob.Raw = GetNextHob (EFI_HOB_TYPE_MEMORY_ALLOCATION, Hob.Raw)) != NULL) { > @@ -570,12 +572,19 @@ SetupStackGuardPage ( > // > MpInitLibStartupThisAP(GetStackBase, Index, NULL, 0, (VOID *)&StackBase, NULL); > } > - // > - // Set Guard page at stack base address. > - // > - ConvertMemoryPageAttributes(StackBase, EFI_PAGE_SIZE, 0); > - DEBUG ((DEBUG_INFO, "Stack Guard set at %lx [cpu%lu]!\n", > - (UINT64)StackBase, (UINT64)Index)); > + > + if (StackBase == 0) { > + DEBUG ((DEBUG_ERROR, "Stack base address was not found for [cpu%lu]!\n", > + (UINT64)Index)); > + ASSERT(StackBase != 0); (4) On the other hand, if it *can* happen in practice that the stack base is not found (and in that case, we should halt), then: * the subject line is wrong, because the compiler warning is *valid*, and we don't suppress it, but fix the issue caught by the compiler; * we must not proceed in a RELEASE build either, therefore an ASSERT is insufficient. A CpuDeadLoop() is necessary. (Again, this only applies if StackBase may be zero here by design.) Thanks Laszlo > + } else { > + // > + // Set Guard page at stack base address. > + // > + ConvertMemoryPageAttributes(StackBase, EFI_PAGE_SIZE, 0); > + DEBUG ((DEBUG_INFO, "Stack Guard set at %lx [cpu%lu]!\n", > + (UINT64)StackBase, (UINT64)Index)); > + } > } > > // > ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-09-12 0:24 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2018-09-11 4:47 [PATCH] UefiCpuPkg/CpuMpPei: suppress compiler complaining Jian J Wang 2018-09-11 14:55 ` Laszlo Ersek 2018-09-12 0:23 ` Wang, Jian J
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox