| Message ID | 20220128131713.299198-1-anders.roxell@linaro.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [PATCHv3] powerpc: mm: radix_tlb: rearrange the if-else block | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 24 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | success | Successfully ran 4 jobs. |
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 7 jobs. |
On Fri, Jan 28, 2022 at 02:17:13PM +0100, Anders Roxell wrote: > Clang warns: > > arch/powerpc/mm/book3s64/radix_tlb.c:1191:23: error: variable 'hstart' is uninitialized when used here [-Werror,-Wuninitialized] > __tlbiel_va_range(hstart, hend, pid, > ^~~~~~ > arch/powerpc/mm/book3s64/radix_tlb.c:1175:23: note: initialize the variable 'hstart' to silence this warning > unsigned long hstart, hend; > ^ > = 0 > arch/powerpc/mm/book3s64/radix_tlb.c:1191:31: error: variable 'hend' is uninitialized when used here [-Werror,-Wuninitialized] > __tlbiel_va_range(hstart, hend, pid, > ^~~~ > arch/powerpc/mm/book3s64/radix_tlb.c:1175:29: note: initialize the variable 'hend' to silence this warning > unsigned long hstart, hend; > ^ > = 0 > 2 errors generated. > > Rework the 'if (IS_ENABLE(CONFIG_TRANSPARENT_HUGEPAGE))' so hstart/hend > always gets initialized, this will silence the warnings. That will also > simplify the 'else' path. Clang is getting confused with these warnings, > but the warnings is a false-positive. > > Suggested-by: Arnd Bergmann <arnd@arndb.de> > Suggested-by: Nathan Chancellor <nathan@kernel.org> > Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> > Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Reviewed-by: Nathan Chancellor <nathan@kernel.org> > --- > arch/powerpc/mm/book3s64/radix_tlb.c | 11 ++++------- > 1 file changed, 4 insertions(+), 7 deletions(-) > > diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c > index 7724af19ed7e..5172d5cec2c0 100644 > --- a/arch/powerpc/mm/book3s64/radix_tlb.c > +++ b/arch/powerpc/mm/book3s64/radix_tlb.c > @@ -1171,15 +1171,12 @@ static inline void __radix__flush_tlb_range(struct mm_struct *mm, > } > } > } else { > - bool hflush = false; > + bool hflush; > unsigned long hstart, hend; > > - if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { > - hstart = (start + PMD_SIZE - 1) & PMD_MASK; > - hend = end & PMD_MASK; > - if (hstart < hend) > - hflush = true; > - } > + hstart = (start + PMD_SIZE - 1) & PMD_MASK; > + hend = end & PMD_MASK; > + hflush = IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && hstart < hend; > > if (type == FLUSH_TYPE_LOCAL) { > asm volatile("ptesync": : :"memory"); > -- > 2.34.1 >
diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c b/arch/powerpc/mm/book3s64/radix_tlb.c index 7724af19ed7e..5172d5cec2c0 100644 --- a/arch/powerpc/mm/book3s64/radix_tlb.c +++ b/arch/powerpc/mm/book3s64/radix_tlb.c @@ -1171,15 +1171,12 @@ static inline void __radix__flush_tlb_range(struct mm_struct *mm, } } } else { - bool hflush = false; + bool hflush; unsigned long hstart, hend; - if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { - hstart = (start + PMD_SIZE - 1) & PMD_MASK; - hend = end & PMD_MASK; - if (hstart < hend) - hflush = true; - } + hstart = (start + PMD_SIZE - 1) & PMD_MASK; + hend = end & PMD_MASK; + hflush = IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && hstart < hend; if (type == FLUSH_TYPE_LOCAL) { asm volatile("ptesync": : :"memory");
Clang warns: arch/powerpc/mm/book3s64/radix_tlb.c:1191:23: error: variable 'hstart' is uninitialized when used here [-Werror,-Wuninitialized] __tlbiel_va_range(hstart, hend, pid, ^~~~~~ arch/powerpc/mm/book3s64/radix_tlb.c:1175:23: note: initialize the variable 'hstart' to silence this warning unsigned long hstart, hend; ^ = 0 arch/powerpc/mm/book3s64/radix_tlb.c:1191:31: error: variable 'hend' is uninitialized when used here [-Werror,-Wuninitialized] __tlbiel_va_range(hstart, hend, pid, ^~~~ arch/powerpc/mm/book3s64/radix_tlb.c:1175:29: note: initialize the variable 'hend' to silence this warning unsigned long hstart, hend; ^ = 0 2 errors generated. Rework the 'if (IS_ENABLE(CONFIG_TRANSPARENT_HUGEPAGE))' so hstart/hend always gets initialized, this will silence the warnings. That will also simplify the 'else' path. Clang is getting confused with these warnings, but the warnings is a false-positive. Suggested-by: Arnd Bergmann <arnd@arndb.de> Suggested-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Anders Roxell <anders.roxell@linaro.org> --- arch/powerpc/mm/book3s64/radix_tlb.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-)