| Message ID | 20221008145437.491-1-jszhang@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 89fd4a1df829187d4d35f6a520cc531de622e6f0 |
| Headers | show |
| Series | [v2] riscv: jump_label: mark arguments as const to satisfy asm constraints | expand |
Am Samstag, 8. Oktober 2022, 16:54:37 CEST schrieb Jisheng Zhang: > Samuel reported that the static branch usage in cpu_relax() breaks > building with CONFIG_CC_OPTIMIZE_FOR_SIZE: > > In file included from <command-line>: > ./arch/riscv/include/asm/jump_label.h: In function 'cpu_relax': > ././include/linux/compiler_types.h:285:33: warning: 'asm' operand 0 > probably does not match constraints > 285 | #define asm_volatile_goto(x...) asm goto(x) > | ^~~ > ./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro > 'asm_volatile_goto' > 41 | asm_volatile_goto( > | ^~~~~~~~~~~~~~~~~ > ././include/linux/compiler_types.h:285:33: error: impossible constraint > in 'asm' > 285 | #define asm_volatile_goto(x...) asm goto(x) > | ^~~ > ./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro > 'asm_volatile_goto' > 41 | asm_volatile_goto( > | ^~~~~~~~~~~~~~~~~ > make[1]: *** [scripts/Makefile.build:249: > arch/riscv/kernel/vdso/vgettimeofday.o] Error 1 > make: *** [arch/riscv/Makefile:128: vdso_prepare] Error 2 > > Maybe "-Os" prevents GCC from detecting that the key/branch arguments > can be treated as constants and used as immediate operands. Inspired > by x86's commit 864b435514b2("x86/jump_label: Mark arguments as const to > satisfy asm constraints"), and as pointed out by Steven: "The "i" > constraint needs to be a constant.", let's do similar modifications to > riscv. > > Tested by CC_OPTIMIZE_FOR_SIZE + gcc and CC_OPTIMIZE_FOR_SIZE + clang. > > Link: https://lore.kernel.org/linux-riscv/20220922060958.44203-1-samuel@sholland.org/ > Link: https://lore.kernel.org/all/20210212094059.5f8d05e8@gandalf.local.home/ > Fixes: 8eb060e10185 ("arch/riscv: add Zihintpause support") > Reported-by: Samuel Holland <samuel@sholland.org> > Signed-off-by: Jisheng Zhang <jszhang@kernel.org> > Reviewed-by: Andrew Jones <ajones@ventanamicro.com> I ran into the same build-issue when enabling CC_OPTIMIZE_FOR_SIZE and this patch fixes it, so Tested-by: Heiko Stuebner <heiko@sntech.de>
Hey Jisheng, LKP reported an error that seems to only have gone to myself & Samuel, but the branch it's complaining about is your v1: https://lore.kernel.org/lkml/202210122123.Cc4FPShJ-lkp@intel.com/ Any idea what the story is here? Thanks, Conor. On Sat, Oct 08, 2022 at 10:54:37PM +0800, Jisheng Zhang wrote: > Samuel reported that the static branch usage in cpu_relax() breaks > building with CONFIG_CC_OPTIMIZE_FOR_SIZE: > > In file included from <command-line>: > ./arch/riscv/include/asm/jump_label.h: In function 'cpu_relax': > ././include/linux/compiler_types.h:285:33: warning: 'asm' operand 0 > probably does not match constraints > 285 | #define asm_volatile_goto(x...) asm goto(x) > | ^~~ > ./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro > 'asm_volatile_goto' > 41 | asm_volatile_goto( > | ^~~~~~~~~~~~~~~~~ > ././include/linux/compiler_types.h:285:33: error: impossible constraint > in 'asm' > 285 | #define asm_volatile_goto(x...) asm goto(x) > | ^~~ > ./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro > 'asm_volatile_goto' > 41 | asm_volatile_goto( > | ^~~~~~~~~~~~~~~~~ > make[1]: *** [scripts/Makefile.build:249: > arch/riscv/kernel/vdso/vgettimeofday.o] Error 1 > make: *** [arch/riscv/Makefile:128: vdso_prepare] Error 2 > > Maybe "-Os" prevents GCC from detecting that the key/branch arguments > can be treated as constants and used as immediate operands. Inspired > by x86's commit 864b435514b2("x86/jump_label: Mark arguments as const to > satisfy asm constraints"), and as pointed out by Steven: "The "i" > constraint needs to be a constant.", let's do similar modifications to > riscv. > > Tested by CC_OPTIMIZE_FOR_SIZE + gcc and CC_OPTIMIZE_FOR_SIZE + clang. > > Link: https://lore.kernel.org/linux-riscv/20220922060958.44203-1-samuel@sholland.org/ > Link: https://lore.kernel.org/all/20210212094059.5f8d05e8@gandalf.local.home/ > Fixes: 8eb060e10185 ("arch/riscv: add Zihintpause support") > Reported-by: Samuel Holland <samuel@sholland.org> > Signed-off-by: Jisheng Zhang <jszhang@kernel.org> > Reviewed-by: Andrew Jones <ajones@ventanamicro.com> > --- > > since v1: > - add Reported-by, Reviewed-by, Fixes and Link tag > > arch/riscv/include/asm/jump_label.h | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/riscv/include/asm/jump_label.h b/arch/riscv/include/asm/jump_label.h > index 38af2ec7b9bf..6d58bbb5da46 100644 > --- a/arch/riscv/include/asm/jump_label.h > +++ b/arch/riscv/include/asm/jump_label.h > @@ -14,8 +14,8 @@ > > #define JUMP_LABEL_NOP_SIZE 4 > > -static __always_inline bool arch_static_branch(struct static_key *key, > - bool branch) > +static __always_inline bool arch_static_branch(struct static_key * const key, > + const bool branch) > { > asm_volatile_goto( > " .option push \n\t" > @@ -35,8 +35,8 @@ static __always_inline bool arch_static_branch(struct static_key *key, > return true; > } > > -static __always_inline bool arch_static_branch_jump(struct static_key *key, > - bool branch) > +static __always_inline bool arch_static_branch_jump(struct static_key * const key, > + const bool branch) > { > asm_volatile_goto( > " .option push \n\t" > -- > 2.37.2 >
On Sat, 8 Oct 2022 22:54:37 +0800, Jisheng Zhang wrote: > Samuel reported that the static branch usage in cpu_relax() breaks > building with CONFIG_CC_OPTIMIZE_FOR_SIZE: > > In file included from <command-line>: > ./arch/riscv/include/asm/jump_label.h: In function 'cpu_relax': > ././include/linux/compiler_types.h:285:33: warning: 'asm' operand 0 > probably does not match constraints > 285 | #define asm_volatile_goto(x...) asm goto(x) > | ^~~ > ./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro > 'asm_volatile_goto' > 41 | asm_volatile_goto( > | ^~~~~~~~~~~~~~~~~ > ././include/linux/compiler_types.h:285:33: error: impossible constraint > in 'asm' > 285 | #define asm_volatile_goto(x...) asm goto(x) > | ^~~ > ./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro > 'asm_volatile_goto' > 41 | asm_volatile_goto( > | ^~~~~~~~~~~~~~~~~ > make[1]: *** [scripts/Makefile.build:249: > arch/riscv/kernel/vdso/vgettimeofday.o] Error 1 > make: *** [arch/riscv/Makefile:128: vdso_prepare] Error 2 > > [...] Applied, thanks! [1/1] riscv: jump_label: mark arguments as const to satisfy asm constraints commit: 89fd4a1df829187d4d35f6a520cc531de622e6f0 Best regards,
On Wed, Oct 12, 2022 at 02:28:16PM +0100, Conor Dooley wrote: > Hey Jisheng, Hi Conor, > LKP reported an error that seems to only have gone to myself & Samuel, > but the branch it's complaining about is your v1: > https://lore.kernel.org/lkml/202210122123.Cc4FPShJ-lkp@intel.com/ > > Any idea what the story is here? I tried the config in the link, I can reproduce the build error w/ and w/o the my patch. So I think the root cause of the build error is a different story. I have a fix in local repo, will send it out soon. Thanks > > Thanks, > Conor. > > On Sat, Oct 08, 2022 at 10:54:37PM +0800, Jisheng Zhang wrote: > > Samuel reported that the static branch usage in cpu_relax() breaks > > building with CONFIG_CC_OPTIMIZE_FOR_SIZE: > > > > In file included from <command-line>: > > ./arch/riscv/include/asm/jump_label.h: In function 'cpu_relax': > > ././include/linux/compiler_types.h:285:33: warning: 'asm' operand 0 > > probably does not match constraints > > 285 | #define asm_volatile_goto(x...) asm goto(x) > > | ^~~ > > ./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro > > 'asm_volatile_goto' > > 41 | asm_volatile_goto( > > | ^~~~~~~~~~~~~~~~~ > > ././include/linux/compiler_types.h:285:33: error: impossible constraint > > in 'asm' > > 285 | #define asm_volatile_goto(x...) asm goto(x) > > | ^~~ > > ./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro > > 'asm_volatile_goto' > > 41 | asm_volatile_goto( > > | ^~~~~~~~~~~~~~~~~ > > make[1]: *** [scripts/Makefile.build:249: > > arch/riscv/kernel/vdso/vgettimeofday.o] Error 1 > > make: *** [arch/riscv/Makefile:128: vdso_prepare] Error 2 > > > > Maybe "-Os" prevents GCC from detecting that the key/branch arguments > > can be treated as constants and used as immediate operands. Inspired > > by x86's commit 864b435514b2("x86/jump_label: Mark arguments as const to > > satisfy asm constraints"), and as pointed out by Steven: "The "i" > > constraint needs to be a constant.", let's do similar modifications to > > riscv. > > > > Tested by CC_OPTIMIZE_FOR_SIZE + gcc and CC_OPTIMIZE_FOR_SIZE + clang. > > > > Link: https://lore.kernel.org/linux-riscv/20220922060958.44203-1-samuel@sholland.org/ > > Link: https://lore.kernel.org/all/20210212094059.5f8d05e8@gandalf.local.home/ > > Fixes: 8eb060e10185 ("arch/riscv: add Zihintpause support") > > Reported-by: Samuel Holland <samuel@sholland.org> > > Signed-off-by: Jisheng Zhang <jszhang@kernel.org> > > Reviewed-by: Andrew Jones <ajones@ventanamicro.com> > > --- > > > > since v1: > > - add Reported-by, Reviewed-by, Fixes and Link tag > > > > arch/riscv/include/asm/jump_label.h | 8 ++++---- > > 1 file changed, 4 insertions(+), 4 deletions(-) > > > > diff --git a/arch/riscv/include/asm/jump_label.h b/arch/riscv/include/asm/jump_label.h > > index 38af2ec7b9bf..6d58bbb5da46 100644 > > --- a/arch/riscv/include/asm/jump_label.h > > +++ b/arch/riscv/include/asm/jump_label.h > > @@ -14,8 +14,8 @@ > > > > #define JUMP_LABEL_NOP_SIZE 4 > > > > -static __always_inline bool arch_static_branch(struct static_key *key, > > - bool branch) > > +static __always_inline bool arch_static_branch(struct static_key * const key, > > + const bool branch) > > { > > asm_volatile_goto( > > " .option push \n\t" > > @@ -35,8 +35,8 @@ static __always_inline bool arch_static_branch(struct static_key *key, > > return true; > > } > > > > -static __always_inline bool arch_static_branch_jump(struct static_key *key, > > - bool branch) > > +static __always_inline bool arch_static_branch_jump(struct static_key * const key, > > + const bool branch) > > { > > asm_volatile_goto( > > " .option push \n\t" > > -- > > 2.37.2 > >
diff --git a/arch/riscv/include/asm/jump_label.h b/arch/riscv/include/asm/jump_label.h index 38af2ec7b9bf..6d58bbb5da46 100644 --- a/arch/riscv/include/asm/jump_label.h +++ b/arch/riscv/include/asm/jump_label.h @@ -14,8 +14,8 @@ #define JUMP_LABEL_NOP_SIZE 4 -static __always_inline bool arch_static_branch(struct static_key *key, - bool branch) +static __always_inline bool arch_static_branch(struct static_key * const key, + const bool branch) { asm_volatile_goto( " .option push \n\t" @@ -35,8 +35,8 @@ static __always_inline bool arch_static_branch(struct static_key *key, return true; } -static __always_inline bool arch_static_branch_jump(struct static_key *key, - bool branch) +static __always_inline bool arch_static_branch_jump(struct static_key * const key, + const bool branch) { asm_volatile_goto( " .option push \n\t"
Samuel reported that the static branch usage in cpu_relax() breaks building with CONFIG_CC_OPTIMIZE_FOR_SIZE: In file included from <command-line>: ./arch/riscv/include/asm/jump_label.h: In function 'cpu_relax': ././include/linux/compiler_types.h:285:33: warning: 'asm' operand 0 probably does not match constraints 285 | #define asm_volatile_goto(x...) asm goto(x) | ^~~ ./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro 'asm_volatile_goto' 41 | asm_volatile_goto( | ^~~~~~~~~~~~~~~~~ ././include/linux/compiler_types.h:285:33: error: impossible constraint in 'asm' 285 | #define asm_volatile_goto(x...) asm goto(x) | ^~~ ./arch/riscv/include/asm/jump_label.h:41:9: note: in expansion of macro 'asm_volatile_goto' 41 | asm_volatile_goto( | ^~~~~~~~~~~~~~~~~ make[1]: *** [scripts/Makefile.build:249: arch/riscv/kernel/vdso/vgettimeofday.o] Error 1 make: *** [arch/riscv/Makefile:128: vdso_prepare] Error 2 Maybe "-Os" prevents GCC from detecting that the key/branch arguments can be treated as constants and used as immediate operands. Inspired by x86's commit 864b435514b2("x86/jump_label: Mark arguments as const to satisfy asm constraints"), and as pointed out by Steven: "The "i" constraint needs to be a constant.", let's do similar modifications to riscv. Tested by CC_OPTIMIZE_FOR_SIZE + gcc and CC_OPTIMIZE_FOR_SIZE + clang. Link: https://lore.kernel.org/linux-riscv/20220922060958.44203-1-samuel@sholland.org/ Link: https://lore.kernel.org/all/20210212094059.5f8d05e8@gandalf.local.home/ Fixes: 8eb060e10185 ("arch/riscv: add Zihintpause support") Reported-by: Samuel Holland <samuel@sholland.org> Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> --- since v1: - add Reported-by, Reviewed-by, Fixes and Link tag arch/riscv/include/asm/jump_label.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)