[PATCH] Make vm86 support optional
This adds an option to remove vm86 support under CONFIG_EMBEDDED. Saves
about 5k.
This version eliminates most of the #ifdefs of the previous version and
instead uses function stubs in vm86.h. Also, release_vm86_irqs is moved
from asm-i386/irq.h to a more appropriate home in vm86.h so that the stubs
can live together.
$ size vmlinux-baseline vmlinux-novm86
text data bss dec hex filename
2920821 523232 190652 3634705 377611 vmlinux-baseline
2916268 523100 190492 3629860 376324 vmlinux-novm86
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile
index 4f40589..be1880b 100644
--- a/arch/i386/kernel/Makefile
+++ b/arch/i386/kernel/Makefile
@@ -4,7 +4,7 @@
extra-y := head.o init_task.o vmlinux.lds
-obj-y := process.o semaphore.o signal.o entry.o traps.o irq.o vm86.o \
+obj-y := process.o semaphore.o signal.o entry.o traps.o irq.o \
ptrace.o time.o ioport.o ldt.o setup.o i8259.o sys_i386.o \
pci-dma.o i386_ksyms.o i387.o dmi_scan.o bootflag.o \
quirks.o i8237.o
@@ -34,6 +34,7 @@
obj-$(CONFIG_HPET_TIMER) += time_hpet.o
obj-$(CONFIG_EFI) += efi.o efi_stub.o
obj-$(CONFIG_DOUBLEFAULT) += doublefault.o
+obj-$(CONFIG_VM86) += vm86.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
EXTRA_AFLAGS := -traditional
diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index 607c060..4d70472 100644
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -323,6 +323,7 @@
ALIGN
work_notifysig_v86:
+#ifdef CONFIG_VM86
pushl %ecx # save ti_flags for do_notify_resume
call save_v86_state # %eax contains pt_regs pointer
popl %ecx
@@ -330,6 +331,7 @@
xorl %edx, %edx
call do_notify_resume
jmp resume_userspace
+#endif
# perform syscall exit tracing
ALIGN
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index 45e7f0a..035928f 100644
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -48,6 +48,7 @@
#include <asm/processor.h>
#include <asm/i387.h>
#include <asm/desc.h>
+#include <asm/vm86.h>
#ifdef CONFIG_MATH_EMULATION
#include <asm/math_emu.h>
#endif
diff --git a/include/asm-i386/irq.h b/include/asm-i386/irq.h
index 270f198..5169d7a 100644
--- a/include/asm-i386/irq.h
+++ b/include/asm-i386/irq.h
@@ -21,8 +21,6 @@
return ((irq == 2) ? 9 : irq);
}
-extern void release_vm86_irqs(struct task_struct *);
-
#ifdef CONFIG_X86_LOCAL_APIC
# define ARCH_HAS_NMI_WATCHDOG /* See include/linux/nmi.h */
#endif
diff --git a/include/asm-i386/vm86.h b/include/asm-i386/vm86.h
index 40ec82c..952fd69 100644
--- a/include/asm-i386/vm86.h
+++ b/include/asm-i386/vm86.h
@@ -16,7 +16,11 @@
#define IF_MASK 0x00000200
#define IOPL_MASK 0x00003000
#define NT_MASK 0x00004000
+#ifdef CONFIG_VM86
#define VM_MASK 0x00020000
+#else
+#define VM_MASK 0 /* ignored */
+#endif
#define AC_MASK 0x00040000
#define VIF_MASK 0x00080000 /* virtual interrupt flag */
#define VIP_MASK 0x00100000 /* virtual interrupt pending */
@@ -200,9 +204,25 @@
*/
};
+#ifdef CONFIG_VM86
+
void handle_vm86_fault(struct kernel_vm86_regs *, long);
int handle_vm86_trap(struct kernel_vm86_regs *, long, int);
+struct task_struct;
+void release_vm86_irqs(struct task_struct *);
+
+#else
+
+#define handle_vm86_fault(a, b)
+#define release_vm86_irqs(a)
+
+static inline int handle_vm86_trap(struct kernel_vm86_regs *a, long b, int c) {
+ return 0;
+}
+
+#endif /* CONFIG_VM86 */
+
#endif /* __KERNEL__ */
#endif
diff --git a/init/Kconfig b/init/Kconfig
index 9ac522a..f8f6929 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -237,6 +237,16 @@
help
This enables the legacy 16-bit UID syscall wrappers.
+config VM86
+ depends X86
+ default y
+ bool "Enable VM86 support" if EMBEDDED
+ help
+ This option is required by programs like DOSEMU to run 16-bit legacy
+ code on X86 processors. It also may be needed by software like
+ XFree86 to initialize some video cards via BIOS. Disabling this
+ option saves about 6k.
+
config CC_OPTIMIZE_FOR_SIZE
bool "Optimize for size (Look out for broken compilers!)"
default y
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 72cafc9..bd3b9bf 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -102,6 +102,8 @@
cond_syscall(sys_setresuid16);
cond_syscall(sys_setreuid16);
cond_syscall(sys_setuid16);
+cond_syscall(sys_vm86old);
+cond_syscall(sys_vm86);
/* arch-specific weak syscall entries */
cond_syscall(sys_pciconfig_read);
