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| author |  Nikolay Borisov <nik.borisov@suse.com>
| 2023-06-23 14:14:08 +0300 |
|---|---|---|
| committer |  Thomas Gleixner <tglx@linutronix.de>
| 2023-09-14 13:19:53 +0200 |
| commit | 61382281e9054df523d3f9cfdba2faff88955f97 (patch) | |
| tree | 5b30d3598d1977deca31c5cff8619a791417eb04 /arch/x86/kernel/idt.c | |
| parent | x86/elf: Make loading of 32bit processes depend on ia32_enabled() (diff) | |
| download | linux-61382281e9054df523d3f9cfdba2faff88955f97.tar.gz linux-61382281e9054df523d3f9cfdba2faff88955f97.tar.bz2 linux-61382281e9054df523d3f9cfdba2faff88955f97.zip | |
x86/entry: Make IA32 syscalls' availability depend on ia32_enabled()
Another major aspect of supporting running of 32bit processes is the
ability to access 32bit syscalls. Such syscalls can be invoked by
using the legacy int 0x80 handler and sysenter/syscall instructions.
If IA32 emulation is disabled ensure that each of those 3 distinct
mechanisms are also disabled. For int 0x80 a #GP exception would be
generated since the respective descriptor is not going to be loaded at
all. Invoking sysenter will also result in a #GP since IA32_SYSENTER_CS
contains an invalid segment. Finally, syscall instruction cannot really
be disabled so it's configured to execute a minimal handler.
Signed-off-by: Nikolay Borisov <nik.borisov@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230623111409.3047467-6-nik.borisov@suse.com
Diffstat (limited to 'arch/x86/kernel/idt.c')
| -rw-r--r-- | arch/x86/kernel/idt.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index b786d48f5a0f..8857abc706e4 100644 --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -10,6 +10,7 @@ #include <asm/proto.h> #include <asm/desc.h> #include <asm/hw_irq.h> +#include <asm/ia32.h> #include <asm/idtentry.h> #define DPL0 0x0 @@ -116,6 +117,9 @@ static const __initconst struct idt_data def_idts[] = { #endif SYSG(X86_TRAP_OF, asm_exc_overflow), +}; + +static const struct idt_data ia32_idt[] __initconst = { #if defined(CONFIG_IA32_EMULATION) SYSG(IA32_SYSCALL_VECTOR, entry_INT80_compat), #elif defined(CONFIG_X86_32) @@ -225,6 +229,9 @@ void __init idt_setup_early_traps(void) void __init idt_setup_traps(void) { idt_setup_from_table(idt_table, def_idts, ARRAY_SIZE(def_idts), true); + + if (ia32_enabled()) + idt_setup_from_table(idt_table, ia32_idt, ARRAY_SIZE(ia32_idt), true); } #ifdef CONFIG_X86_64 |