From: Andy Chiu Date: Mon, 7 Apr 2025 18:08:25 +0000 (+0800) Subject: riscv: ftrace: support fastcc in Clang for WITH_ARGS X-Git-Tag: v6.16-rc1~18^2~5^2~9^2~11 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f8693f6dffcd1865da7f5f4c3df1de445e519bec;p=thirdparty%2Fkernel%2Flinux.git riscv: ftrace: support fastcc in Clang for WITH_ARGS Some caller-saved registers which are not defined as function arguments in the ABI can still be passed as arguments when the kernel is compiled with Clang. As a result, we must save and restore those registers to prevent ftrace from clobbering them. - [1]: https://reviews.llvm.org/D68559 Reported-by: Evgenii Shatokhin Closes: https://lore.kernel.org/linux-riscv/7e7c7914-445d-426d-89a0-59a9199c45b1@yadro.com/ Fixes: 7caa9765465f ("ftrace: riscv: move from REGS to ARGS") Acked-by: Nathan Chancellor Reviewed-by: Björn Töpel Signed-off-by: Andy Chiu Tested-by: Björn Töpel Link: https://lore.kernel.org/r/20250407180838.42877-1-andybnac@gmail.com Signed-off-by: Alexandre Ghiti Signed-off-by: Palmer Dabbelt --- diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h index d627f63ee289c..d8b2138bd9c66 100644 --- a/arch/riscv/include/asm/ftrace.h +++ b/arch/riscv/include/asm/ftrace.h @@ -146,6 +146,13 @@ struct __arch_ftrace_regs { unsigned long a5; unsigned long a6; unsigned long a7; +#ifdef CONFIG_CC_IS_CLANG + unsigned long t2; + unsigned long t3; + unsigned long t4; + unsigned long t5; + unsigned long t6; +#endif }; }; }; diff --git a/arch/riscv/kernel/asm-offsets.c b/arch/riscv/kernel/asm-offsets.c index 16490755304e0..7c43c8e26ae7f 100644 --- a/arch/riscv/kernel/asm-offsets.c +++ b/arch/riscv/kernel/asm-offsets.c @@ -501,6 +501,13 @@ void asm_offsets(void) DEFINE(FREGS_SP, offsetof(struct __arch_ftrace_regs, sp)); DEFINE(FREGS_S0, offsetof(struct __arch_ftrace_regs, s0)); DEFINE(FREGS_T1, offsetof(struct __arch_ftrace_regs, t1)); +#ifdef CONFIG_CC_IS_CLANG + DEFINE(FREGS_T2, offsetof(struct __arch_ftrace_regs, t2)); + DEFINE(FREGS_T3, offsetof(struct __arch_ftrace_regs, t3)); + DEFINE(FREGS_T4, offsetof(struct __arch_ftrace_regs, t4)); + DEFINE(FREGS_T5, offsetof(struct __arch_ftrace_regs, t5)); + DEFINE(FREGS_T6, offsetof(struct __arch_ftrace_regs, t6)); +#endif DEFINE(FREGS_A0, offsetof(struct __arch_ftrace_regs, a0)); DEFINE(FREGS_A1, offsetof(struct __arch_ftrace_regs, a1)); DEFINE(FREGS_A2, offsetof(struct __arch_ftrace_regs, a2)); diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S index 745dd4c4a69c3..e988bd26b28bd 100644 --- a/arch/riscv/kernel/mcount-dyn.S +++ b/arch/riscv/kernel/mcount-dyn.S @@ -96,7 +96,13 @@ REG_S x8, FREGS_S0(sp) #endif REG_S x6, FREGS_T1(sp) - +#ifdef CONFIG_CC_IS_CLANG + REG_S x7, FREGS_T2(sp) + REG_S x28, FREGS_T3(sp) + REG_S x29, FREGS_T4(sp) + REG_S x30, FREGS_T5(sp) + REG_S x31, FREGS_T6(sp) +#endif // save the arguments REG_S x10, FREGS_A0(sp) REG_S x11, FREGS_A1(sp) @@ -115,7 +121,13 @@ REG_L x8, FREGS_S0(sp) #endif REG_L x6, FREGS_T1(sp) - +#ifdef CONFIG_CC_IS_CLANG + REG_L x7, FREGS_T2(sp) + REG_L x28, FREGS_T3(sp) + REG_L x29, FREGS_T4(sp) + REG_L x30, FREGS_T5(sp) + REG_L x31, FREGS_T6(sp) +#endif // restore the arguments REG_L x10, FREGS_A0(sp) REG_L x11, FREGS_A1(sp)