This is a note to let you know that I've just added the patch titled riscv: jump_label: mark arguments as const to satisfy asm constraints to the 6.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: riscv-jump_label-mark-arguments-as-const-to-satisfy-.patch and it can be found in the queue-6.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 7064ee7fac10c82d1404e269762c24cd6619061f Author: Jisheng Zhang <jszhang@xxxxxxxxxx> Date: Sat Oct 8 22:54:37 2022 +0800 riscv: jump_label: mark arguments as const to satisfy asm constraints [ Upstream commit 89fd4a1df829187d4d35f6a520cc531de622e6f0 ] 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@xxxxxxxxxxxx/ Link: https://lore.kernel.org/all/20210212094059.5f8d05e8@xxxxxxxxxxxxxxxxxx/ Fixes: 8eb060e10185 ("arch/riscv: add Zihintpause support") Reported-by: Samuel Holland <samuel@xxxxxxxxxxxx> Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx> Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx> Tested-by: Heiko Stuebner <heiko@xxxxxxxxx> Link: https://lore.kernel.org/r/20221008145437.491-1-jszhang@xxxxxxxxxx Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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"