| Message ID | 49B7FE80.1010307@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Wed, Mar 11, 2009 at 3:10 PM, Jochen Roth <jroth@linux.vnet.ibm.com> wrote: > FYI > > I just discovered a potential gcc bug which causes kvm-userspace builds to > break. > I looks like it happens only with the latest fedora rawhide gcc 4.4 > https://bugzilla.redhat.com/show_bug.cgi?id=489753 > > The following patch circumvents this problem by just renaming R to REG. > People facing the same problem might find this patch useful. > Adding a space between the R is a much better fix, since nothing guarantees gcc won't use "REG" in the future too. Eduardo sent a fix for this a while ago, but it was not applied.
Glauber Costa wrote: > On Wed, Mar 11, 2009 at 3:10 PM, Jochen Roth <jroth@linux.vnet.ibm.com> wrote: >> FYI >> >> I just discovered a potential gcc bug which causes kvm-userspace builds to >> break. >> I looks like it happens only with the latest fedora rawhide gcc 4.4 >> https://bugzilla.redhat.com/show_bug.cgi?id=489753 >> >> The following patch circumvents this problem by just renaming R to REG. >> People facing the same problem might find this patch useful. >> > Adding a space between the R is a much better fix, since nothing guarantees > gcc won't use "REG" in the future too. > > Eduardo sent a fix for this a while ago, but it was not applied. > Jakub just closed the bug. It works as designed: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2442.htm Shall I send another patch with spaces or do you plan to apply Eduardo's patch?
On Wed, Mar 11, 2009 at 3:30 PM, Jochen Roth <jroth@linux.vnet.ibm.com> wrote: > Glauber Costa wrote: >> >> On Wed, Mar 11, 2009 at 3:10 PM, Jochen Roth <jroth@linux.vnet.ibm.com> >> wrote: >>> >>> FYI >>> >>> I just discovered a potential gcc bug which causes kvm-userspace builds >>> to >>> break. >>> I looks like it happens only with the latest fedora rawhide gcc 4.4 >>> https://bugzilla.redhat.com/show_bug.cgi?id=489753 >>> >>> The following patch circumvents this problem by just renaming R to REG. >>> People facing the same problem might find this patch useful. >>> >> Adding a space between the R is a much better fix, since nothing >> guarantees >> gcc won't use "REG" in the future too. >> >> Eduardo sent a fix for this a while ago, but it was not applied. >> > > Jakub just closed the bug. It works as designed: > http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2442.htm > > Shall I send another patch with spaces or do you plan to apply Eduardo's > patch? anthony?
Glauber Costa wrote: > On Wed, Mar 11, 2009 at 3:30 PM, Jochen Roth <jroth@linux.vnet.ibm.com> wrote: > >> Glauber Costa wrote: >> >>> On Wed, Mar 11, 2009 at 3:10 PM, Jochen Roth <jroth@linux.vnet.ibm.com> >>> wrote: >>> >>>> FYI >>>> >>>> I just discovered a potential gcc bug which causes kvm-userspace builds >>>> to >>>> break. >>>> I looks like it happens only with the latest fedora rawhide gcc 4.4 >>>> https://bugzilla.redhat.com/show_bug.cgi?id=489753 >>>> >>>> The following patch circumvents this problem by just renaming R to REG. >>>> People facing the same problem might find this patch useful. >>>> >>>> >>> Adding a space between the R is a much better fix, since nothing >>> guarantees >>> gcc won't use "REG" in the future too. >>> >>> Eduardo sent a fix for this a while ago, but it was not applied. >>> >>> >> Jakub just closed the bug. It works as designed: >> http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2442.htm >> >> Shall I send another patch with spaces or do you plan to apply Eduardo's >> patch? >> > > anthony? > I haven't seen a patch against QEMU... Was it sent to qemu-devel? Regards, Anthony Liguori -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/user/test/x86/apic.c b/user/test/x86/apic.c index 9c6205b..ec3777c 100644 --- a/user/test/x86/apic.c +++ b/user/test/x86/apic.c @@ -35,9 +35,9 @@ typedef struct { } isr_regs_t; #ifdef __x86_64__ -# define R "r" +# define REG "r" #else -# define R "e" +# define REG "e" #endif extern char isr_entry_point[]; @@ -54,14 +54,14 @@ asm ( "push %r9 \n\t" "push %r8 \n\t" #endif - "push %"R"di \n\t" - "push %"R"si \n\t" - "push %"R"bp \n\t" - "push %"R"sp \n\t" - "push %"R"bx \n\t" - "push %"R"dx \n\t" - "push %"R"cx \n\t" - "push %"R"ax \n\t" + "push %"REG"di \n\t" + "push %"REG"si \n\t" + "push %"REG"bp \n\t" + "push %"REG"sp \n\t" + "push %"REG"bx \n\t" + "push %"REG"dx \n\t" + "push %"REG"cx \n\t" + "push %"REG"ax \n\t" #ifdef __x86_64__ "mov %rsp, %rdi \n\t" "callq *8*16(%rsp) \n\t" @@ -70,14 +70,14 @@ asm ( "calll *4+4*8(%esp) \n\t" "add $4, %esp \n\t" #endif - "pop %"R"ax \n\t" - "pop %"R"cx \n\t" - "pop %"R"dx \n\t" - "pop %"R"bx \n\t" - "pop %"R"bp \n\t" - "pop %"R"bp \n\t" - "pop %"R"si \n\t" - "pop %"R"di \n\t" + "pop %"REG"ax \n\t" + "pop %"REG"cx \n\t" + "pop %"REG"dx \n\t" + "pop %"REG"bx \n\t" + "pop %"REG"bp \n\t" + "pop %"REG"bp \n\t" + "pop %"REG"si \n\t" + "pop %"REG"di \n\t" #ifdef __x86_64__ "pop %r8 \n\t" "pop %r9 \n\t" diff --git a/user/test/x86/vmexit.c b/user/test/x86/vmexit.c index bd57bfa..bc81be9 100644 --- a/user/test/x86/vmexit.c +++ b/user/test/x86/vmexit.c @@ -19,9 +19,9 @@ static inline unsigned long long rdtsc() #define N (1 << 22) #ifdef __x86_64__ -# define R "r" +# define REG "r" #else -# define R "e" +# define REG "e" #endif int main() @@ -31,7 +31,7 @@ int main() t1 = rdtsc(); for (i = 0; i < N; ++i) - asm volatile ("push %%"R"bx; cpuid; pop %%"R"bx" + asm volatile ("push %%"REG"bx; cpuid; pop %%"REG"bx" : : : "eax", "ecx", "edx"); t2 = rdtsc(); printf("vmexit latency: %d\n", (int)((t2 - t1) / N));