From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 393F913D8A6; Sat, 10 Aug 2024 21:27:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723325242; cv=none; b=EfRFKRh3jvdv2K27xXFhjaWQvsIgX9XMV32WW05XNpdDI9c/IaienNjf4RIPuSZNa14tm0D0mRlb624tRXLN4yq5kycEjRmJ1hC+UWVrxBsrnqofzPJw3LrHCRpiUWGOaG49HitHo4b2ssbjR3K1NDXWB/X6IKcpXB/0tmjv6v8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723325242; c=relaxed/simple; bh=UFw18Biowc+RS3ZsThhCPHGYPTxWeuACsU0OGuHWq/E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aOrdtH+Xz24W+V0D94pvyER72g+b6Mq+CKow0EJ4oiQAdrIS9zFEmBoTcEbPJ0EGXB9L0EQq/GOwTGagBAM2Q+BoAYD1W7GCldcmgSV8gfnMn0HgPtbO5HQGPXqd0hE1vhb6Ipk/TlRUNXzuh11wSPLB9lHzR7d/gzkL26RhVfE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=SlodpyVH; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="SlodpyVH" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=QS4maoDE9j0FPQOAXgzzsa6/fUJQHH67QENNS+2ljQI=; b=SlodpyVHbHOHc5JsqYBNEK43LL xWYoqz26t8JR2c+GPCw5A3SN/gWdzaf9NYgioguHIg8/Ppvyj603Ac8juUxZo2TFtxlGC+GXUq/v/ AvmyS9U25DC+acTebH9fSQIAhq28P7tudVeZu/8+pfKCTZtUdfn29A/vlGks5kVY/A+64Otsp/J5F BQ1viAkQnQrBxjJhgcEczOTZY8T8w1SCs1E2D4yCr/RMADTmF+a9Y1yPlh8fXZWyzEx29ceU6m+lK eziSg60W10jAC+fiWNbEtYlOMHfdJEbSMjq2vPgLRbu965BE+0Aw/Jm5A6oyOvU6F94pfgTz2mlmG S9UHZ2fg==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1sctbx-00000007Fnm-43XW; Sat, 10 Aug 2024 21:26:54 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 041B7300729; Sat, 10 Aug 2024 23:26:53 +0200 (CEST) Date: Sat, 10 Aug 2024 23:26:52 +0200 From: Peter Zijlstra To: Alice Ryhl Cc: Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Josh Poimboeuf , Jason Baron , Ard Biesheuvel , Miguel Ojeda , Alex Gaynor , Wedson Almeida Filho , Boqun Feng , Gary Guo , =?iso-8859-1?Q?Bj=F6rn?= Roy Baron , Benno Lossin , Andreas Hindborg , linux-trace-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Arnd Bergmann , linux-arch@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Sean Christopherson , Uros Bizjak , Catalin Marinas , Will Deacon , Marc Zyngier , Oliver Upton , Mark Rutland , Ryan Roberts , Fuad Tabba , linux-arm-kernel@lists.infradead.org, Paul Walmsley , Palmer Dabbelt , Albert Ou , Anup Patel , Andrew Jones , Alexandre Ghiti , Conor Dooley , Samuel Holland , linux-riscv@lists.infradead.org, Huacai Chen , WANG Xuerui , Bibo Mao , Tiezhu Yang , Andrew Morton , Tianrui Zhao , loongarch@lists.linux.dev Subject: Re: [PATCH v6 4/5] jump_label: adjust inline asm to be consistent Message-ID: <20240810212652.GE11646@noisy.programming.kicks-ass.net> References: <20240808-tracepoint-v6-0-a23f800f1189@google.com> <20240808-tracepoint-v6-4-a23f800f1189@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240808-tracepoint-v6-4-a23f800f1189@google.com> On Thu, Aug 08, 2024 at 05:23:40PM +0000, Alice Ryhl wrote: > To avoid duplication of inline asm between C and Rust, we need to > import the inline asm from the relevant `jump_label.h` header into Rust. > To make that easier, this patch updates the header files to expose the > inline asm via a new ARCH_STATIC_BRANCH_ASM macro. > > The header files are all updated to define a ARCH_STATIC_BRANCH_ASM that > takes the same arguments in a consistent order so that Rust can use the > same logic for every architecture. > > Link: https://lore.kernel.org/r/20240725183325.122827-7-ojeda@kernel.org [1] > Signed-off-by: Alice Ryhl I can't help but notice your risc-v conversion is much nicer than the one you did for ARM. But I'm not going to complain too loudly about that. It's a shame about that 2 for JUMP_LABEL_HACK, having to lift that nonsense all the way to Rust, but alas. This will do, thanks! Acked-by: Peter Zijlstra (Intel) > --- > arch/arm/include/asm/jump_label.h | 14 +++++---- > arch/arm64/include/asm/jump_label.h | 20 ++++++++----- > arch/loongarch/include/asm/jump_label.h | 16 +++++++---- > arch/riscv/include/asm/jump_label.h | 50 ++++++++++++++++++--------------- > arch/x86/include/asm/jump_label.h | 38 ++++++++++--------------- > 5 files changed, 75 insertions(+), 63 deletions(-) > > diff --git a/arch/arm/include/asm/jump_label.h b/arch/arm/include/asm/jump_label.h > index e4eb54f6cd9f..a35aba7f548c 100644 > --- a/arch/arm/include/asm/jump_label.h > +++ b/arch/arm/include/asm/jump_label.h > @@ -9,13 +9,17 @@ > > #define JUMP_LABEL_NOP_SIZE 4 > > +/* This macro is also expanded on the Rust side. */ > +#define ARCH_STATIC_BRANCH_ASM(key, label) \ > + "1:\n\t" \ > + WASM(nop) "\n\t" \ > + ".pushsection __jump_table, \"aw\"\n\t" \ > + ".word 1b, " label ", " key "\n\t" \ > + ".popsection\n\t" \ > + > static __always_inline bool arch_static_branch(struct static_key *key, bool branch) > { > - asm goto("1:\n\t" > - WASM(nop) "\n\t" > - ".pushsection __jump_table, \"aw\"\n\t" > - ".word 1b, %l[l_yes], %c0\n\t" > - ".popsection\n\t" > + asm goto(ARCH_STATIC_BRANCH_ASM("%c0", "%l[l_yes]") > : : "i" (&((char *)key)[branch]) : : l_yes); > > return false; > diff --git a/arch/arm64/include/asm/jump_label.h b/arch/arm64/include/asm/jump_label.h > index a0a5bbae7229..424ed421cd97 100644 > --- a/arch/arm64/include/asm/jump_label.h > +++ b/arch/arm64/include/asm/jump_label.h > @@ -19,10 +19,14 @@ > #define JUMP_TABLE_ENTRY(key, label) \ > ".pushsection __jump_table, \"aw\"\n\t" \ > ".align 3\n\t" \ > - ".long 1b - ., %l["#label"] - .\n\t" \ > - ".quad %c0 - .\n\t" \ > - ".popsection\n\t" \ > - : : "i"(key) : : label > + ".long 1b - ., " label " - .\n\t" \ > + ".quad " key " - .\n\t" \ > + ".popsection\n\t" > + > +/* This macro is also expanded on the Rust side. */ > +#define ARCH_STATIC_BRANCH_ASM(key, label) \ > + "1: nop\n\t" \ > + JUMP_TABLE_ENTRY(key, label) > > static __always_inline bool arch_static_branch(struct static_key * const key, > const bool branch) > @@ -30,8 +34,8 @@ static __always_inline bool arch_static_branch(struct static_key * const key, > char *k = &((char *)key)[branch]; > > asm goto( > - "1: nop \n\t" > - JUMP_TABLE_ENTRY(k, l_yes) > + ARCH_STATIC_BRANCH_ASM("%c0", "%l[l_yes]") > + : : "i"(k) : : l_yes > ); > > return false; > @@ -43,9 +47,11 @@ static __always_inline bool arch_static_branch_jump(struct static_key * const ke > const bool branch) > { > char *k = &((char *)key)[branch]; > + > asm goto( > "1: b %l[l_yes] \n\t" > - JUMP_TABLE_ENTRY(k, l_yes) > + JUMP_TABLE_ENTRY("%c0", "%l[l_yes]") > + : : "i"(k) : : l_yes > ); > return false; > l_yes: > diff --git a/arch/loongarch/include/asm/jump_label.h b/arch/loongarch/include/asm/jump_label.h > index 29acfe3de3fa..8a924bd69d19 100644 > --- a/arch/loongarch/include/asm/jump_label.h > +++ b/arch/loongarch/include/asm/jump_label.h > @@ -13,18 +13,22 @@ > > #define JUMP_LABEL_NOP_SIZE 4 > > -#define JUMP_TABLE_ENTRY \ > +/* This macro is also expanded on the Rust side. */ > +#define JUMP_TABLE_ENTRY(key, label) \ > ".pushsection __jump_table, \"aw\" \n\t" \ > ".align 3 \n\t" \ > - ".long 1b - ., %l[l_yes] - . \n\t" \ > - ".quad %0 - . \n\t" \ > + ".long 1b - ., " label " - . \n\t" \ > + ".quad " key " - . \n\t" \ > ".popsection \n\t" > > +#define ARCH_STATIC_BRANCH_ASM(key, label) \ > + "1: nop \n\t" \ > + JUMP_TABLE_ENTRY(key, label) > + > static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch) > { > asm goto( > - "1: nop \n\t" > - JUMP_TABLE_ENTRY > + ARCH_STATIC_BRANCH_ASM("%0", "%l[l_yes]") > : : "i"(&((char *)key)[branch]) : : l_yes); > > return false; > @@ -37,7 +41,7 @@ static __always_inline bool arch_static_branch_jump(struct static_key * const ke > { > asm goto( > "1: b %l[l_yes] \n\t" > - JUMP_TABLE_ENTRY > + JUMP_TABLE_ENTRY("%0", "%l[l_yes]") > : : "i"(&((char *)key)[branch]) : : l_yes); > > return false; > diff --git a/arch/riscv/include/asm/jump_label.h b/arch/riscv/include/asm/jump_label.h > index 1c768d02bd0c..f6342d456372 100644 > --- a/arch/riscv/include/asm/jump_label.h > +++ b/arch/riscv/include/asm/jump_label.h > @@ -16,21 +16,28 @@ > > #define JUMP_LABEL_NOP_SIZE 4 > > +#define JUMP_TABLE_ENTRY(key, label) \ > + ".pushsection __jump_table, \"aw\" \n\t" \ > + ".align " RISCV_LGPTR " \n\t" \ > + ".long 1b - ., " label " - . \n\t" \ > + "" RISCV_PTR " " key " - . \n\t" \ > + ".popsection \n\t" > + > +/* This macro is also expanded on the Rust side. */ > +#define ARCH_STATIC_BRANCH_ASM(key, label) \ > + " .align 2 \n\t" \ > + " .option push \n\t" \ > + " .option norelax \n\t" \ > + " .option norvc \n\t" \ > + "1: j " label " \n\t" \ > + " .option pop \n\t" \ > + JUMP_TABLE_ENTRY(key, label) > + > static __always_inline bool arch_static_branch(struct static_key * const key, > const bool branch) > { > asm goto( > - " .align 2 \n\t" > - " .option push \n\t" > - " .option norelax \n\t" > - " .option norvc \n\t" > - "1: nop \n\t" > - " .option pop \n\t" > - " .pushsection __jump_table, \"aw\" \n\t" > - " .align " RISCV_LGPTR " \n\t" > - " .long 1b - ., %l[label] - . \n\t" > - " " RISCV_PTR " %0 - . \n\t" > - " .popsection \n\t" > + ARCH_STATIC_BRANCH_ASM("%0", "%l[label]") > : : "i"(&((char *)key)[branch]) : : label); > > return false; > @@ -38,21 +45,20 @@ static __always_inline bool arch_static_branch(struct static_key * const key, > return true; > } > > +#define ARCH_STATIC_BRANCH_JUMP_ASM(key, label) \ > + " .align 2 \n\t" \ > + " .option push \n\t" \ > + " .option norelax \n\t" \ > + " .option norvc \n\t" \ > + "1: nop \n\t" \ > + " .option pop \n\t" \ > + JUMP_TABLE_ENTRY(key, label) > + > static __always_inline bool arch_static_branch_jump(struct static_key * const key, > const bool branch) > { > asm goto( > - " .align 2 \n\t" > - " .option push \n\t" > - " .option norelax \n\t" > - " .option norvc \n\t" > - "1: j %l[label] \n\t" > - " .option pop \n\t" > - " .pushsection __jump_table, \"aw\" \n\t" > - " .align " RISCV_LGPTR " \n\t" > - " .long 1b - ., %l[label] - . \n\t" > - " " RISCV_PTR " %0 - . \n\t" > - " .popsection \n\t" > + ARCH_STATIC_BRANCH_JUMP_ASM("%0", "%l[label]") > : : "i"(&((char *)key)[branch]) : : label); > > return false; > diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h > index cbbef32517f0..87a3a0f5bd22 100644 > --- a/arch/x86/include/asm/jump_label.h > +++ b/arch/x86/include/asm/jump_label.h > @@ -12,49 +12,41 @@ > #include > #include > > -#define JUMP_TABLE_ENTRY \ > +#define JUMP_TABLE_ENTRY(key, label) \ > ".pushsection __jump_table, \"aw\" \n\t" \ > _ASM_ALIGN "\n\t" \ > ".long 1b - . \n\t" \ > - ".long %l[l_yes] - . \n\t" \ > - _ASM_PTR "%c0 + %c1 - .\n\t" \ > + ".long " label "- . \n\t" \ > + _ASM_PTR " " key " - . \n\t" \ > ".popsection \n\t" > > +/* This macro is also expanded on the Rust side. */ > #ifdef CONFIG_HAVE_JUMP_LABEL_HACK > - > -static __always_inline bool arch_static_branch(struct static_key *key, bool branch) > -{ > - asm goto("1:" > - "jmp %l[l_yes] # objtool NOPs this \n\t" > - JUMP_TABLE_ENTRY > - : : "i" (key), "i" (2 | branch) : : l_yes); > - > - return false; > -l_yes: > - return true; > -} > - > +#define ARCH_STATIC_BRANCH_ASM(key, label) \ > + "1: jmp " label " # objtool NOPs this \n\t" \ > + JUMP_TABLE_ENTRY(key, label) > #else /* !CONFIG_HAVE_JUMP_LABEL_HACK */ > +#define ARCH_STATIC_BRANCH_ASM(key, label) \ > + "1: .byte " __stringify(BYTES_NOP5) "\n\t" \ > + JUMP_TABLE_ENTRY(key, label) > +#endif /* CONFIG_HAVE_JUMP_LABEL_HACK */ > > static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch) > { > - asm goto("1:" > - ".byte " __stringify(BYTES_NOP5) "\n\t" > - JUMP_TABLE_ENTRY > - : : "i" (key), "i" (branch) : : l_yes); > + int hack_bit = IS_ENABLED(CONFIG_HAVE_JUMP_LABEL_HACK) ? 2 : 0; > + asm goto(ARCH_STATIC_BRANCH_ASM("%c0 + %c1", "%l[l_yes]") > + : : "i" (key), "i" (hack_bit | branch) : : l_yes); > > return false; > l_yes: > return true; > } > > -#endif /* CONFIG_HAVE_JUMP_LABEL_HACK */ > - > static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch) > { > asm goto("1:" > "jmp %l[l_yes]\n\t" > - JUMP_TABLE_ENTRY > + JUMP_TABLE_ENTRY("%c0 + %c1", "%l[l_yes]") > : : "i" (key), "i" (branch) : : l_yes); > > return false; > > -- > 2.46.0.76.ge559c4bf1a-goog >