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Modify existing code to use those macros. Signed-off-by: Juergen Gross --- arch/x86/sched.c | 32 +++++++++----------------------- include/x86/os.h | 19 +++++++++++-------- 2 files changed, 20 insertions(+), 31 deletions(-) diff --git a/arch/x86/sched.c b/arch/x86/sched.c index dabe6fd6..460dea2e 100644 --- a/arch/x86/sched.c +++ b/arch/x86/sched.c @@ -60,16 +60,10 @@ void dump_stack(struct thread *thread) unsigned long *bottom = (unsigned long *)(thread->stack + STACK_SIZE); unsigned long *pointer = (unsigned long *)thread->sp; int count; - if(thread == current) - { -#ifdef __i386__ - asm("movl %%esp,%0" - : "=r"(pointer)); -#else - asm("movq %%rsp,%0" - : "=r"(pointer)); -#endif - } + + if ( thread == current ) + asm(ASM_MOV" "ASM_SP",%0" : "=r"(pointer)); + printk("The stack for \"%s\"\n", thread->name); for(count = 0; count < 25 && pointer < bottom; count ++) { @@ -119,20 +113,12 @@ struct thread* arch_create_thread(char *name, void (*function)(void *), void run_idle_thread(void) { - /* Switch stacks and run the thread */ -#if defined(__i386__) - __asm__ __volatile__("mov %0,%%esp\n\t" - "push %1\n\t" - "ret" + /* Switch stacks and run the thread */ + __asm__ __volatile__("mov %0,"ASM_SP"\n\t" + "push %1\n\t" + "ret" :"=m" (idle_thread->sp) - :"m" (idle_thread->ip)); -#elif defined(__x86_64__) - __asm__ __volatile__("mov %0,%%rsp\n\t" - "push %1\n\t" - "ret" - :"=m" (idle_thread->sp) - :"m" (idle_thread->ip)); -#endif + :"m" (idle_thread->ip)); } unsigned long __local_irq_save(void) diff --git a/include/x86/os.h b/include/x86/os.h index ee34d784..485d90b8 100644 --- a/include/x86/os.h +++ b/include/x86/os.h @@ -77,6 +77,17 @@ int arch_suspend(void); void arch_post_suspend(int canceled); void arch_fini(void); +#if defined(__i386__) +#define __SZ "l" +#define __REG "e" +#else +#define __SZ "q" +#define __REG "r" +#endif + +#define ASM_SP "%%"__REG"sp" +#define ASM_MOV "mov"__SZ + #ifdef CONFIG_PARAVIRT /* @@ -141,14 +152,6 @@ do { \ #else -#if defined(__i386__) -#define __SZ "l" -#define __REG "e" -#else -#define __SZ "q" -#define __REG "r" -#endif - #define __cli() asm volatile ( "cli" : : : "memory" ) #define __sti() asm volatile ( "sti" : : : "memory" ) -- 2.35.3 From minios-devel-bounces@lists.xenproject.org Tue Apr 16 10:56:12 2024 Return-path: Envelope-to: archives@lists.xenproject.org Delivery-date: Tue, 16 Apr 2024 10:56:12 +0000 Received: from list by lists.xenproject.org with outflank-mailman.706877.1104324 (Exim 4.92) (envelope-from ) id 1rwgTy-00083y-Tw; Tue, 16 Apr 2024 10:56:10 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 706877.1104324; Tue, 16 Apr 2024 10:56:10 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1rwgTy-000837-PL; Tue, 16 Apr 2024 10:56:10 +0000 Received: by outflank-mailman (input) for mailman id 706877; Tue, 16 Apr 2024 10:56:09 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1rwgTx-00080w-Qg for minios-devel@lists.xenproject.org; Tue, 16 Apr 2024 10:56:09 +0000 Received: from mail-qv1-xf32.google.com (mail-qv1-xf32.google.com [2607:f8b0:4864:20::f32]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id ecd88420-fbdf-11ee-94a3-07e782e9044d; Tue, 16 Apr 2024 12:56:07 +0200 (CEST) Received: by mail-qv1-xf32.google.com with SMTP id 6a1803df08f44-69b4043b7b3so18937876d6.1 for ; Tue, 16 Apr 2024 03:56:07 -0700 (PDT) Received: from [10.80.67.140] (default-46-102-197-194.interdsl.co.uk. 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Tue, 16 Apr 2024 03:56:05 -0700 (PDT) Message-ID: <10e8d4a3-2e53-478c-bb77-a038f2187c5a@citrix.com> Date: Tue, 16 Apr 2024 11:56:03 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] Mini-OS: add some macros for asm statements To: Juergen Gross , minios-devel@lists.xenproject.org, xen-devel@lists.xenproject.org Cc: samuel.thibault@ens-lyon.org References: <20240416071139.11083-1-jgross@suse.com> Content-Language: en-GB From: Andrew Cooper Autocrypt: addr=andrew.cooper3@citrix.com; keydata= xsFNBFLhNn8BEADVhE+Hb8i0GV6mihnnr/uiQQdPF8kUoFzCOPXkf7jQ5sLYeJa0cQi6Penp VtiFYznTairnVsN5J+ujSTIb+OlMSJUWV4opS7WVNnxHbFTPYZVQ3erv7NKc2iVizCRZ2Kxn srM1oPXWRic8BIAdYOKOloF2300SL/bIpeD+x7h3w9B/qez7nOin5NzkxgFoaUeIal12pXSR Q354FKFoy6Vh96gc4VRqte3jw8mPuJQpfws+Pb+swvSf/i1q1+1I4jsRQQh2m6OTADHIqg2E ofTYAEh7R5HfPx0EXoEDMdRjOeKn8+vvkAwhviWXTHlG3R1QkbE5M/oywnZ83udJmi+lxjJ5 YhQ5IzomvJ16H0Bq+TLyVLO/VRksp1VR9HxCzItLNCS8PdpYYz5TC204ViycobYU65WMpzWe LFAGn8jSS25XIpqv0Y9k87dLbctKKA14Ifw2kq5OIVu2FuX+3i446JOa2vpCI9GcjCzi3oHV e00bzYiHMIl0FICrNJU0Kjho8pdo0m2uxkn6SYEpogAy9pnatUlO+erL4LqFUO7GXSdBRbw5 gNt25XTLdSFuZtMxkY3tq8MFss5QnjhehCVPEpE6y9ZjI4XB8ad1G4oBHVGK5LMsvg22PfMJ ISWFSHoF/B5+lHkCKWkFxZ0gZn33ju5n6/FOdEx4B8cMJt+cWwARAQABzSlBbmRyZXcgQ29v cGVyIDxhbmRyZXcuY29vcGVyM0BjaXRyaXguY29tPsLBegQTAQgAJAIbAwULCQgHAwUVCgkI CwUWAgMBAAIeAQIXgAUCWKD95wIZAQAKCRBlw/kGpdefoHbdD/9AIoR3k6fKl+RFiFpyAhvO 59ttDFI7nIAnlYngev2XUR3acFElJATHSDO0ju+hqWqAb8kVijXLops0gOfqt3VPZq9cuHlh IMDquatGLzAadfFx2eQYIYT+FYuMoPZy/aTUazmJIDVxP7L383grjIkn+7tAv+qeDfE+txL4 SAm1UHNvmdfgL2/lcmL3xRh7sub3nJilM93RWX1Pe5LBSDXO45uzCGEdst6uSlzYR/MEr+5Z JQQ32JV64zwvf/aKaagSQSQMYNX9JFgfZ3TKWC1KJQbX5ssoX/5hNLqxMcZV3TN7kU8I3kjK mPec9+1nECOjjJSO/h4P0sBZyIUGfguwzhEeGf4sMCuSEM4xjCnwiBwftR17sr0spYcOpqET ZGcAmyYcNjy6CYadNCnfR40vhhWuCfNCBzWnUW0lFoo12wb0YnzoOLjvfD6OL3JjIUJNOmJy RCsJ5IA/Iz33RhSVRmROu+TztwuThClw63g7+hoyewv7BemKyuU6FTVhjjW+XUWmS/FzknSi dAG+insr0746cTPpSkGl3KAXeWDGJzve7/SBBfyznWCMGaf8E2P1oOdIZRxHgWj0zNr1+ooF /PzgLPiCI4OMUttTlEKChgbUTQ+5o0P080JojqfXwbPAyumbaYcQNiH1/xYbJdOFSiBv9rpt TQTBLzDKXok86M7BTQRS4TZ/ARAAkgqudHsp+hd82UVkvgnlqZjzz2vyrYfz7bkPtXaGb9H4 Rfo7mQsEQavEBdWWjbga6eMnDqtu+FC+qeTGYebToxEyp2lKDSoAsvt8w82tIlP/EbmRbDVn 7bhjBlfRcFjVYw8uVDPptT0TV47vpoCVkTwcyb6OltJrvg/QzV9f07DJswuda1JH3/qvYu0p vjPnYvCq4NsqY2XSdAJ02HrdYPFtNyPEntu1n1KK+gJrstjtw7KsZ4ygXYrsm/oCBiVW/OgU g/XIlGErkrxe4vQvJyVwg6YH653YTX5hLLUEL1NS4TCo47RP+wi6y+TnuAL36UtK/uFyEuPy wwrDVcC4cIFhYSfsO0BumEI65yu7a8aHbGfq2lW251UcoU48Z27ZUUZd2Dr6O/n8poQHbaTd 6bJJSjzGGHZVbRP9UQ3lkmkmc0+XCHmj5WhwNNYjgbbmML7y0fsJT5RgvefAIFfHBg7fTY/i kBEimoUsTEQz+N4hbKwo1hULfVxDJStE4sbPhjbsPCrlXf6W9CxSyQ0qmZ2bXsLQYRj2xqd1 bpA+1o1j2N4/au1R/uSiUFjewJdT/LX1EklKDcQwpk06Af/N7VZtSfEJeRV04unbsKVXWZAk uAJyDDKN99ziC0Wz5kcPyVD1HNf8bgaqGDzrv3TfYjwqayRFcMf7xJaL9xXedMcAEQEAAcLB XwQYAQgACQUCUuE2fwIbDAAKCRBlw/kGpdefoG4XEACD1Qf/er8EA7g23HMxYWd3FXHThrVQ HgiGdk5Yh632vjOm9L4sd/GCEACVQKjsu98e8o3ysitFlznEns5EAAXEbITrgKWXDDUWGYxd pnjj2u+GkVdsOAGk0kxczX6s+VRBhpbBI2PWnOsRJgU2n10PZ3mZD4Xu9kU2IXYmuW+e5KCA vTArRUdCrAtIa1k01sPipPPw6dfxx2e5asy21YOytzxuWFfJTGnVxZZSCyLUO83sh6OZhJkk b9rxL9wPmpN/t2IPaEKoAc0FTQZS36wAMOXkBh24PQ9gaLJvfPKpNzGD8XWR5HHF0NLIJhgg 4ZlEXQ2fVp3XrtocHqhu4UZR4koCijgB8sB7Tb0GCpwK+C4UePdFLfhKyRdSXuvY3AHJd4CP 4JzW0Bzq/WXY3XMOzUTYApGQpnUpdOmuQSfpV9MQO+/jo7r6yPbxT7CwRS5dcQPzUiuHLK9i nvjREdh84qycnx0/6dDroYhp0DFv4udxuAvt1h4wGwTPRQZerSm4xaYegEFusyhbZrI0U9tJ B8WrhBLXDiYlyJT6zOV2yZFuW47VrLsjYnHwn27hmxTC/7tvG3euCklmkn9Sl9IAKFu29RSo d5bD8kMSCYsTqtTfT6W4A3qHGvIDta3ptLYpIAOD2sY3GYq2nf3Bbzx81wZK14JdDDHUX2Rs 6+ahAA== In-Reply-To: <20240416071139.11083-1-jgross@suse.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 16/04/2024 8:11 am, Juergen Gross wrote: > diff --git a/arch/x86/sched.c b/arch/x86/sched.c > index dabe6fd6..460dea2e 100644 > --- a/arch/x86/sched.c > +++ b/arch/x86/sched.c > @@ -119,20 +113,12 @@ struct thread* arch_create_thread(char *name, void (*function)(void *), > > void run_idle_thread(void) > { > - /* Switch stacks and run the thread */ > -#if defined(__i386__) > - __asm__ __volatile__("mov %0,%%esp\n\t" > - "push %1\n\t" > - "ret" > + /* Switch stacks and run the thread */ > + __asm__ __volatile__("mov %0,"ASM_SP"\n\t" > + "push %1\n\t" > + "ret" > :"=m" (idle_thread->sp) > - :"m" (idle_thread->ip)); > -#elif defined(__x86_64__) > - __asm__ __volatile__("mov %0,%%rsp\n\t" > - "push %1\n\t" > - "ret" > - :"=m" (idle_thread->sp) > - :"m" (idle_thread->ip)); > -#endif > + :"m" (idle_thread->ip)); I know you're only transforming the existing logic, but this is dodgy in several ways. First, PUSH/RET is more commonly spelt JMP.  Second, sp is an input parameter not an output, so I'm pretty sure this only works by luck. 00000000000001ee :  1ee:   55                      push   %rbp  1ef:   48 89 e5                mov    %rsp,%rbp  1f2:   48 8b 05 00 00 00 00    mov    0x0(%rip),%rax        # 1f9  1f9:   48 8b 15 00 00 00 00    mov    0x0(%rip),%rdx        # 200  200:   48 8b 60 10             mov    0x10(%rax),%rsp  204:   ff 72 18                pushq  0x18(%rdx)  207:   c3                      retq     208:   90                      nop  209:   5d                      pop    %rbp  20a:   c3                      retq    This only works because the address constructed for sp's "output" is happens to be on a single-parameter instruction where's its good as an input too. Anyway, this is a much better way of writing it:     asm volatile ("mov %[sp], %%"ASM_SP"\n\t"                   "jmp *%[ip]\n\t"                   :                   : [sp] "m" (idle_thread->sp),                     [ip] "m" (idle_thread->ip)); and also highlights that run_idle_thread() should be marked noreturn. > } > > unsigned long __local_irq_save(void) > diff --git a/include/x86/os.h b/include/x86/os.h > index ee34d784..485d90b8 100644 > --- a/include/x86/os.h > +++ b/include/x86/os.h > @@ -77,6 +77,17 @@ int arch_suspend(void); > void arch_post_suspend(int canceled); > void arch_fini(void); > > +#if defined(__i386__) > +#define __SZ "l" > +#define __REG "e" > +#else > +#define __SZ "q" > +#define __REG "r" > +#endif > + > +#define ASM_SP "%%"__REG"sp" The %% should be at the usage sites, not here.  That way, you can use ASM_SP in e.g. file-scope asm where it's spelt with a single %. > +#define ASM_MOV "mov"__SZ There's no need for ASM_MOV.  Regular plain mov (no suffix) will work in all the cases you're trying to use it, and makes the asm easier to read.  Notice how run_idle_thread() is already like this. ~Andrew