From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Josh Poimboeuf <jpoimboe@kernel.org>, x86@kernel.org
Cc: linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Borislav Petkov <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>,
Uros Bizjak <ubizjak@gmail.com>, Ingo Molnar <mingo@kernel.org>
Subject: Re: [PATCH 17/20] x86/smap: Use named asm operands in smap_{save,restore}()
Date: Fri, 14 Mar 2025 22:51:36 +0000 [thread overview]
Message-ID: <313e0c9d-9733-4216-980a-cb473fbb5475@citrix.com> (raw)
In-Reply-To: <4631b5fb3e33af925f4bd82ecb56a5facff354cf.1741988314.git.jpoimboe@kernel.org>
On 14/03/2025 9:41 pm, Josh Poimboeuf wrote:
> @@ -50,9 +50,9 @@ static __always_inline unsigned long smap_save(void)
> static __always_inline void smap_restore(unsigned long flags)
> {
> asm volatile ("# smap_restore\n\t"
> - ALTERNATIVE("", "push %0; popf\n\t",
> - X86_FEATURE_SMAP)
> - : : "g" (flags) : "memory", "cc");
> + ALTERNATIVE("",
> + "push %[flags]; popf\n\t", X86_FEATURE_SMAP)
> + : : [flags] "g" (flags) : "memory", "cc");
> }
>
> /* These macros can be used in asm() statements */
The problem with ASM_CALL_CONSTRAINT and asm_call() is that it's not
just call instructions. It's any transient stack adjustment.
Peeking forwards the other half of the series, you convert IRET to
asm_call(), but leave these alone.
These need converting, and hopefully someone can think of a better name
than "call" to be used for the wrapper.
~Andrew
next prev parent reply other threads:[~2025-03-14 22:51 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-14 21:41 [PATCH 00/20] x86: Cleanup alternative_io() and friends, prep for asm_call() Josh Poimboeuf
2025-03-14 21:41 ` [PATCH 01/20] x86/cpu: Use named asm operands in prefetch[w]() Josh Poimboeuf
2025-03-14 21:41 ` [PATCH 02/20] x86/apic: Use named asm operands in native_apic_mem_write() Josh Poimboeuf
2025-03-14 21:41 ` [PATCH 03/20] x86/mm: Use named asm operands in task_size_max() Josh Poimboeuf
2025-03-14 21:41 ` [PATCH 04/20] x86/cpu: Use named asm operands in clflushopt() Josh Poimboeuf
2025-03-14 23:46 ` Linus Torvalds
2025-03-15 0:07 ` Josh Poimboeuf
2025-03-15 8:42 ` Ingo Molnar
2025-03-15 9:25 ` Ingo Molnar
2025-03-14 21:41 ` [PATCH 05/20] x86/asm: Always use flag output operands Josh Poimboeuf
2025-03-14 21:41 ` [PATCH 06/20] x86/asm: Remove CC_SET() Josh Poimboeuf
2025-03-15 9:25 ` Uros Bizjak
2025-03-14 21:41 ` [PATCH 07/20] x86/alternative: Remove operand numbering restrictions Josh Poimboeuf
2025-03-14 21:41 ` [PATCH 08/20] x86/asm: Replace ASM_{OUTPUT,INPUT}() with ARG() Josh Poimboeuf
2025-03-14 21:41 ` [PATCH 09/20] x86/alternative: Simplify alternative_io() interface Josh Poimboeuf
2025-03-14 21:41 ` [PATCH 10/20] x86/alternative: Add alternative_2_io() Josh Poimboeuf
2025-03-14 21:41 ` [PATCH 11/20] x86/alternative: Make alternative() a wrapper around alternative_io() Josh Poimboeuf
2025-03-14 21:41 ` [PATCH 12/20] x86/cpu: Use alternative_io() in prefetch[w]() Josh Poimboeuf
2025-03-14 21:41 ` [PATCH 13/20] x86/alternative: Remove alternative_input() Josh Poimboeuf
2025-03-14 21:41 ` [PATCH 14/20] x86/barrier: Use alternative_io() in 32-bit barrier functions Josh Poimboeuf
2025-03-14 23:49 ` Linus Torvalds
2025-03-14 23:54 ` Linus Torvalds
2025-03-15 0:09 ` Josh Poimboeuf
2025-03-15 0:16 ` Linus Torvalds
2025-03-15 8:47 ` Ingo Molnar
2025-03-15 0:05 ` Josh Poimboeuf
2025-03-15 9:14 ` Ingo Molnar
2025-03-17 20:04 ` David Laight
2025-03-18 0:11 ` Josh Poimboeuf
2025-03-18 22:06 ` David Laight
2025-03-18 22:29 ` Josh Poimboeuf
2025-03-15 8:52 ` Ingo Molnar
2025-03-14 21:41 ` [PATCH 15/20] x86/cpu/amd: Use named asm operands in asm_clear_divider() Josh Poimboeuf
2025-03-15 9:01 ` Uros Bizjak
2025-03-15 10:00 ` Uros Bizjak
2025-03-14 21:41 ` [PATCH 16/20] x86/cpu: Use alternative_io() in amd_clear_divider() Josh Poimboeuf
2025-03-15 9:03 ` Uros Bizjak
2025-03-14 21:41 ` [PATCH 17/20] x86/smap: Use named asm operands in smap_{save,restore}() Josh Poimboeuf
2025-03-14 22:51 ` Andrew Cooper [this message]
2025-03-14 23:56 ` Andrew Cooper
2025-03-14 21:41 ` [PATCH 18/20] x86/smap: Use alternative_io() " Josh Poimboeuf
2025-03-15 9:09 ` Uros Bizjak
2025-03-14 21:41 ` [PATCH 19/20] x86/uaccess: Use alternative_io() in __untagged_addr() Josh Poimboeuf
2025-03-15 9:12 ` Uros Bizjak
2025-03-14 21:41 ` [PATCH 20/20] x86/msr: Use alternative_2_io() in rdtsc_ordered() Josh Poimboeuf
2025-03-14 22:25 ` [PATCH 00/20] x86: Cleanup alternative_io() and friends, prep for asm_call() Josh Poimboeuf
2025-03-15 9:52 ` Uros Bizjak
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