From: Nikolay Borisov <nik.borisov@suse.com>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org, mhocko@suse.com, jslaby@suse.cz,
Nikolay Borisov <nik.borisov@suse.com>
Subject: [PATCH v2 2/4] x86/entry: Rename ignore_sysret and compile it unconditionally
Date: Fri, 9 Jun 2023 14:13:09 +0300 [thread overview]
Message-ID: <20230609111311.4110901-3-nik.borisov@suse.com> (raw)
In-Reply-To: <20230609111311.4110901-1-nik.borisov@suse.com>
Give ignore_sysret a more descriptive name as it's actually used to make
32bit syscalls a noop and return ENOSYS, rather than doing anything
special to sysret. While at it also compile the function unconditinally
as this is going to be used in the patch disabling ia32 syscalls due to
'ia32_disabled' parameter.
Signed-off-by: Nikolay Borisov <nik.borisov@suse.com>
---
arch/x86/entry/entry_64.S | 6 ++----
arch/x86/include/asm/processor.h | 2 +-
arch/x86/kernel/cpu/common.c | 2 +-
3 files changed, 4 insertions(+), 6 deletions(-)
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index f31e286c2977..7068af44008a 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1514,18 +1514,16 @@ 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.
*/
-SYM_CODE_START(ignore_sysret)
+SYM_CODE_START(entry_SYSCALL32_ignore)
UNWIND_HINT_END_OF_STACK
ENDBR
mov $-ENOSYS, %eax
sysretl
-SYM_CODE_END(ignore_sysret)
-#endif
+SYM_CODE_END(entry_SYSCALL32_ignore)
.pushsection .text, "ax"
__FUNC_ALIGN
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index a1e4fa58b357..61c10b4e3e35 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -399,7 +399,7 @@ static inline unsigned long cpu_kernelmode_gs_base(int cpu)
return (unsigned long)per_cpu(fixed_percpu_data.gs_base, cpu);
}
-extern asmlinkage void ignore_sysret(void);
+extern asmlinkage void entry_SYSCALL32_ignore(void);
/* Save actual FS/GS selectors and bases to current->thread */
void current_save_fsgs(void);
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 80710a68ef7d..b20774181e1a 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -2066,7 +2066,7 @@ void syscall_init(void)
(unsigned long)(cpu_entry_stack(smp_processor_id()) + 1));
wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)entry_SYSENTER_compat);
#else
- wrmsrl_cstar((unsigned long)ignore_sysret);
+ wrmsrl_cstar((unsigned long)entry_SYSCALL32_ignore);
wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)GDT_ENTRY_INVALID_SEG);
wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
wrmsrl_safe(MSR_IA32_SYSENTER_EIP, 0ULL);
--
2.34.1
next prev parent reply other threads:[~2023-06-09 11:13 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-09 11:13 [PATCH v2 0/4] Make IA32_EMULATION boot time overridable Nikolay Borisov
2023-06-09 11:13 ` [PATCH v2 1/4] x86: Introduce CONFIG_IA32_EMULATION_DEFAULT_DISABLED Kconfig option Nikolay Borisov
2023-06-09 15:06 ` Thomas Gleixner
2023-06-10 2:21 ` Randy Dunlap
2023-06-09 11:13 ` Nikolay Borisov [this message]
2023-06-09 15:08 ` [PATCH v2 2/4] x86/entry: Rename ignore_sysret and compile it unconditionally Thomas Gleixner
2023-06-09 11:13 ` [PATCH v2 3/4] x86/entry: Disable IA32 syscall if ia32_disabled is true Nikolay Borisov
2023-06-09 15:22 ` Thomas Gleixner
2023-06-09 16:03 ` Nikolay Borisov
2023-06-09 16:13 ` Nikolay Borisov
2023-06-10 11:26 ` Thomas Gleixner
2023-06-09 11:13 ` [PATCH v2 4/4] x86: Disable laoding 32bit processes " Nikolay Borisov
2023-06-09 15:26 ` Thomas Gleixner
2023-06-09 16:45 ` Brian Gerst
2023-06-10 21:46 ` [PATCH v2 0/4] Make IA32_EMULATION boot time overridable David Laight
2023-06-11 8:19 ` Nikolay Borisov
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