Messages in this thread Patch in this message | | | Date | Mon, 7 Nov 2005 20:37:25 -0800 | Subject | [PATCH 17/21] i386 Ldt cleanups 1 | From | Zachary Amsden <> |
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Big cleanup of LDT code. This code has very little type checking and is not frequently used, so I audited the code, added type checking and size optimizations to generate smaller assembly code.
First, just introduce some small definitions that will be used later.
Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.14-zach-work/arch/i386/kernel/entry.S =================================================================== --- linux-2.6.14-zach-work.orig/arch/i386/kernel/entry.S 2005-10-27 17:02:08.000000000 -0700 +++ linux-2.6.14-zach-work/arch/i386/kernel/entry.S 2005-11-04 18:22:07.000000000 -0800 @@ -250,8 +250,8 @@ restore_all: # See comments in process.c:copy_thread() for details. movb OLDSS(%esp), %ah movb CS(%esp), %al - andl $(VM_MASK | (4 << 8) | 3), %eax - cmpl $((4 << 8) | 3), %eax + andl $(VM_MASK | (LDT_SEGMENT << 8) | 3), %eax + cmpl $((LDT_SEGMENT << 8) | 3), %eax je ldt_ss # returning to user-space with LDT SS restore_nocheck: RESTORE_REGS Index: linux-2.6.14-zach-work/arch/i386/kernel/ptrace.c =================================================================== --- linux-2.6.14-zach-work.orig/arch/i386/kernel/ptrace.c 2005-11-04 18:30:27.000000000 -0800 +++ linux-2.6.14-zach-work/arch/i386/kernel/ptrace.c 2005-11-05 00:28:04.000000000 -0800 @@ -146,8 +146,6 @@ static unsigned long getreg(struct task_ return retval; } -#define LDT_SEGMENT 4 - static unsigned long convert_eip_to_linear(struct task_struct *child, struct pt_regs *regs) { unsigned long addr, seg; Index: linux-2.6.14-zach-work/include/asm-i386/segment.h =================================================================== --- linux-2.6.14-zach-work.orig/include/asm-i386/segment.h 2005-11-04 15:46:51.000000000 -0800 +++ linux-2.6.14-zach-work/include/asm-i386/segment.h 2005-11-04 18:22:07.000000000 -0800 @@ -121,4 +121,9 @@ */ #define IDT_ENTRIES 256 +/* + * This bit is set to indicate segment selectors are in the LDT + */ +#define LDT_SEGMENT 4 + #endif Index: linux-2.6.14-zach-work/include/asm-i386/ldt.h =================================================================== --- linux-2.6.14-zach-work.orig/include/asm-i386/ldt.h 2005-10-27 17:02:08.000000000 -0700 +++ linux-2.6.14-zach-work/include/asm-i386/ldt.h 2005-11-04 18:22:07.000000000 -0800 @@ -10,6 +10,8 @@ #define LDT_ENTRIES 8192 /* The size of each LDT entry. */ #define LDT_ENTRY_SIZE 8 +/* The number of LDT entries per page */ +#define LDT_ENTRIES_PER_PAGE (PAGE_SIZE / LDT_ENTRY_SIZE) #ifndef __ASSEMBLY__ struct user_desc { - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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