| Message ID | 20250210155615.1545738-1-cleger@rivosinc.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 1508ead3d2292555c02550f5512c9b0ff537aeb6 |
| Headers | show |
| Series | riscv: cpufeature: use bitmap_equal() instead of memcmp() | expand |
| Context | Check | Description |
|---|---|---|
| bjorn/pre-ci_am | success | Success |
| bjorn/build-rv32-defconfig | success | build-rv32-defconfig |
| bjorn/build-rv64-clang-allmodconfig | success | build-rv64-clang-allmodconfig |
| bjorn/build-rv64-gcc-allmodconfig | success | build-rv64-gcc-allmodconfig |
| bjorn/build-rv64-nommu-k210-defconfig | success | build-rv64-nommu-k210-defconfig |
| bjorn/build-rv64-nommu-k210-virt | success | build-rv64-nommu-k210-virt |
| bjorn/checkpatch | success | checkpatch |
| bjorn/dtb-warn-rv64 | success | dtb-warn-rv64 |
| bjorn/header-inline | success | header-inline |
| bjorn/kdoc | success | kdoc |
| bjorn/module-param | success | module-param |
| bjorn/verify-fixes | success | verify-fixes |
| bjorn/verify-signedoff | success | verify-signedoff |
Hi Clément, On 10/02/2025 16:56, Clément Léger wrote: > Comparison of bitmaps should be done using bitmap_equal(), not memcmp(), > use the former one to compare isa bitmaps. > > Signed-off-by: Clément Léger <cleger@rivosinc.com> > --- > arch/riscv/kernel/cpufeature.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c > index c6ba750536c3..40ac72e407b6 100644 > --- a/arch/riscv/kernel/cpufeature.c > +++ b/arch/riscv/kernel/cpufeature.c > @@ -479,7 +479,7 @@ static void __init riscv_resolve_isa(unsigned long *source_isa, > if (bit < RISCV_ISA_EXT_BASE) > *this_hwcap |= isa2hwcap[bit]; > } > - } while (loop && memcmp(prev_resolved_isa, resolved_isa, sizeof(prev_resolved_isa))); > + } while (loop && !bitmap_equal(prev_resolved_isa, resolved_isa, RISCV_ISA_EXT_MAX)); > } > > static void __init match_isa_ext(const char *name, const char *name_end, unsigned long *bitmap) Since bitmap does not guarantee the value of the 'extra' bits (https://elixir.bootlin.com/linux/v6.13.1/source/lib/bitmap.c#L24), this is a fix so I would add a Fixes tag: Fixes: 625034abd52a8c ("riscv: add ISA extensions validation callback") You can also add: Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Thanks, Alex
On 11/02/2025 08:41, Alexandre Ghiti wrote: > Hi Clément, > > On 10/02/2025 16:56, Clément Léger wrote: >> Comparison of bitmaps should be done using bitmap_equal(), not memcmp(), >> use the former one to compare isa bitmaps. >> >> Signed-off-by: Clément Léger <cleger@rivosinc.com> >> --- >> arch/riscv/kernel/cpufeature.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/ >> cpufeature.c >> index c6ba750536c3..40ac72e407b6 100644 >> --- a/arch/riscv/kernel/cpufeature.c >> +++ b/arch/riscv/kernel/cpufeature.c >> @@ -479,7 +479,7 @@ static void __init riscv_resolve_isa(unsigned long >> *source_isa, >> if (bit < RISCV_ISA_EXT_BASE) >> *this_hwcap |= isa2hwcap[bit]; >> } >> - } while (loop && memcmp(prev_resolved_isa, resolved_isa, >> sizeof(prev_resolved_isa))); >> + } while (loop && !bitmap_equal(prev_resolved_isa, resolved_isa, >> RISCV_ISA_EXT_MAX)); >> } >> static void __init match_isa_ext(const char *name, const char >> *name_end, unsigned long *bitmap) > > > Since bitmap does not guarantee the value of the 'extra' bits (https:// > elixir.bootlin.com/linux/v6.13.1/source/lib/bitmap.c#L24), this is a fix > so I would add a Fixes tag: > > Fixes: 625034abd52a8c ("riscv: add ISA extensions validation callback") Yeah, I wasn't sure since it does not fix anything per se. We aligned the ISA size to a multiple of 64 (128) so we actually do not have any extra undefined bits. But I agree that it's better to track it correctly as a fix. That makes me think that we could actually size RISCV_ISA_EXT_MAX to be exactly the number of ISA extensions we support rather than a larger arbitrary value. > > You can also add: > > Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Thanks ! Clément > > Thanks, > > Alex >
Hello: This patch was applied to riscv/linux.git (fixes) by Palmer Dabbelt <palmer@rivosinc.com>: On Mon, 10 Feb 2025 16:56:14 +0100 you wrote: > Comparison of bitmaps should be done using bitmap_equal(), not memcmp(), > use the former one to compare isa bitmaps. > > Signed-off-by: Clément Léger <cleger@rivosinc.com> > --- > arch/riscv/kernel/cpufeature.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Here is the summary with links: - riscv: cpufeature: use bitmap_equal() instead of memcmp() https://git.kernel.org/riscv/c/1508ead3d229 You are awesome, thank you!
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index c6ba750536c3..40ac72e407b6 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -479,7 +479,7 @@ static void __init riscv_resolve_isa(unsigned long *source_isa, if (bit < RISCV_ISA_EXT_BASE) *this_hwcap |= isa2hwcap[bit]; } - } while (loop && memcmp(prev_resolved_isa, resolved_isa, sizeof(prev_resolved_isa))); + } while (loop && !bitmap_equal(prev_resolved_isa, resolved_isa, RISCV_ISA_EXT_MAX)); } static void __init match_isa_ext(const char *name, const char *name_end, unsigned long *bitmap)
Comparison of bitmaps should be done using bitmap_equal(), not memcmp(), use the former one to compare isa bitmaps. Signed-off-by: Clément Léger <cleger@rivosinc.com> --- arch/riscv/kernel/cpufeature.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)