The following commit has been merged into the x86/entry branch of tip: Commit-ID: f71e1d2ff8e6a183bd4004bc97c453ba527b7dc6 Gitweb: https://git.kernel.org/tip/f71e1d2ff8e6a183bd4004bc97c453ba527b7dc6 Author: Nikolay Borisov <nik.borisov@xxxxxxxx> AuthorDate: Fri, 23 Jun 2023 14:14:05 +03:00 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitterDate: Thu, 14 Sep 2023 13:19:53 +02:00 x86/entry: Rename ignore_sysret() The SYSCALL instruction cannot really be disabled in compatibility mode. The best that can be done is to configure the CSTAR msr to point to a minimal handler. Currently this handler has a rather misleading name - ignore_sysret() as it's not really doing anything with sysret. Give it a more descriptive name. Signed-off-by: Nikolay Borisov <nik.borisov@xxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20230623111409.3047467-3-nik.borisov@xxxxxxxx --- arch/x86/entry/entry_64.S | 4 ++-- arch/x86/include/asm/processor.h | 2 +- arch/x86/kernel/cpu/common.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 43606de..3be71ac 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1516,12 +1516,12 @@ SYM_CODE_END(asm_exc_nmi) * 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) +SYM_CODE_END(entry_SYSCALL32_ignore) #endif .pushsection .text, "ax" diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 0086920..93cd28d 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 382d4e6..b3f8cba 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -2087,7 +2087,7 @@ 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);
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