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From: Nikolay Borisov <nik.borisov@suse.com>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org, mohocko@suse.com, jslaby@suse.cz,
	Nikolay Borisov <nik.borisov@suse.com>
Subject: [PATCH v4 3/6] x86/entry: Compile entry_SYSCALL32_ignore() unconditionally
Date: Fri, 23 Jun 2023 14:14:06 +0300	[thread overview]
Message-ID: <20230623111409.3047467-4-nik.borisov@suse.com> (raw)
In-Reply-To: <20230623111409.3047467-1-nik.borisov@suse.com>

To limit the IA32 exposure on 64bit kernels while keeping the
flexibility for the user to enable it when required, the compile time
enable/disable via CONFIG_IA32_EMULATION is not good enough and will
be complemented with a kernel command line option.

Right now entry_SYSCALL32_ignore() is only compiled when
CONFIG_IA32_EMULATION=n, but boot-time enable- / disablement obviously
requires it to be unconditionally available.

Remove the #ifndef CONFIG_IA32_EMULATION guard.

Signed-off-by: Nikolay Borisov <nik.borisov@suse.com>
---
 arch/x86/entry/entry_64.S | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index ccce0ccd8589..7068af44008a 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1514,7 +1514,6 @@ SYM_CODE_START(asm_exc_nmi)
 	iretq
 SYM_CODE_END(asm_exc_nmi)
 
-#ifndef CONFIG_IA32_EMULATION
 /*
  * This handles SYSCALL from 32-bit code.  There is no way to program
  * MSRs to fully disable 32-bit SYSCALL.
@@ -1525,7 +1524,6 @@ SYM_CODE_START(entry_SYSCALL32_ignore)
 	mov	$-ENOSYS, %eax
 	sysretl
 SYM_CODE_END(entry_SYSCALL32_ignore)
-#endif
 
 .pushsection .text, "ax"
 	__FUNC_ALIGN
-- 
2.34.1


  parent reply	other threads:[~2023-06-23 11:14 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-23 11:14 [PATCH v4 0/6] Make IA32_EMULATION boot time overridable Nikolay Borisov
2023-06-23 11:14 ` [PATCH v4 1/6] x86: Introduce ia32_enabled() Nikolay Borisov
2023-06-30 11:18   ` Thomas Gleixner
2023-06-30 11:44     ` Thomas Gleixner
2023-09-14 11:27   ` [tip: x86/entry] " tip-bot2 for Nikolay Borisov
2023-06-23 11:14 ` [PATCH v4 2/6] x86/entry: Rename ignore_sysret() Nikolay Borisov
2023-09-14 11:27   ` [tip: x86/entry] " tip-bot2 for Nikolay Borisov
2023-06-23 11:14 ` Nikolay Borisov [this message]
2023-09-14 11:27   ` [tip: x86/entry] x86/entry: Compile entry_SYSCALL32_ignore() unconditionally tip-bot2 for Nikolay Borisov
2023-06-23 11:14 ` [PATCH v4 4/6] x86/elf: Make loading of 32bit processes depend on ia32_enabled() Nikolay Borisov
2023-09-14 11:27   ` [tip: x86/entry] " tip-bot2 for Nikolay Borisov
2023-06-23 11:14 ` [PATCH v4 5/6] x86/entry: Make IA32 syscalls' availability " Nikolay Borisov
2023-09-14 11:27   ` [tip: x86/entry] " tip-bot2 for Nikolay Borisov
2023-06-23 11:14 ` [PATCH v4 6/6] x86: Make IA32_EMULATION boot time configurable Nikolay Borisov
2023-09-14 11:27   ` [tip: x86/entry] " tip-bot2 for Nikolay Borisov

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