From: Bodo Stroesser Date: Thu, 19 Jan 2006 01:42:39 +0000 (-0800) Subject: [PATCH] uml: move LDT creation X-Git-Tag: v2.6.16-rc2~335 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=12919aa6e015dd85170fc3b1a3e10a5dfd116c72;p=linux-2.6-omap-h63xx.git [PATCH] uml: move LDT creation s390 doesn't have a LDT. So MM_COPY_SEGMENTS will not be supported on s390. The only user of MM_COPY_SEGMENTS is new_mm(), but that's no longer useful, as arch/sys-i386/ldt.c defines init_new_ldt(), which is called immediately after new_mm(). So we should copy host's LDT in init_new_ldt(), if /proc/mm is available, to have this subarch specific call in subarch code. Signed-off-by: Bodo Stroesser Signed-off-by: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/um/kernel/skas/include/skas.h b/arch/um/kernel/skas/include/skas.h index 01d489de398..a7f7cd556f1 100644 --- a/arch/um/kernel/skas/include/skas.h +++ b/arch/um/kernel/skas/include/skas.h @@ -33,7 +33,7 @@ extern int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len, int r, int w, int x, int done, void **data); extern void user_signal(int sig, union uml_pt_regs *regs, int pid); -extern int new_mm(int from, unsigned long stack); +extern int new_mm(unsigned long stack); extern int start_userspace(unsigned long stub_stack); extern int copy_context_skas0(unsigned long stack, int pid); extern void get_skas_faultinfo(int pid, struct faultinfo * fi); diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c index 677871f1b37..c5c9885a829 100644 --- a/arch/um/kernel/skas/mmu.c +++ b/arch/um/kernel/skas/mmu.c @@ -78,7 +78,7 @@ int init_new_context_skas(struct task_struct *task, struct mm_struct *mm) struct mmu_context_skas *from_mm = NULL; struct mmu_context_skas *to_mm = &mm->context.skas; unsigned long stack = 0; - int from_fd, ret = -ENOMEM; + int ret = -ENOMEM; if(skas_needs_stub){ stack = get_zeroed_page(GFP_KERNEL); @@ -108,11 +108,7 @@ int init_new_context_skas(struct task_struct *task, struct mm_struct *mm) from_mm = ¤t->mm->context.skas; if(proc_mm){ - if(from_mm) - from_fd = from_mm->id.u.mm_fd; - else from_fd = -1; - - ret = new_mm(from_fd, stack); + ret = new_mm(stack); if(ret < 0){ printk("init_new_context_skas - new_mm failed, " "errno = %d\n", ret); diff --git a/arch/um/kernel/skas/process_kern.c b/arch/um/kernel/skas/process_kern.c index dc41c6dc2f3..fcddee76c7c 100644 --- a/arch/um/kernel/skas/process_kern.c +++ b/arch/um/kernel/skas/process_kern.c @@ -20,7 +20,6 @@ #include "tlb.h" #include "kern.h" #include "mode.h" -#include "proc_mm.h" #include "registers.h" void switch_to_skas(void *prev, void *next) @@ -125,25 +124,14 @@ int copy_thread_skas(int nr, unsigned long clone_flags, unsigned long sp, extern void map_stub_pages(int fd, unsigned long code, unsigned long data, unsigned long stack); -int new_mm(int from, unsigned long stack) +int new_mm(unsigned long stack) { - struct proc_mm_op copy; - int n, fd; + int fd; fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0); if(fd < 0) return(fd); - if(from != -1){ - copy = ((struct proc_mm_op) { .op = MM_COPY_SEGMENTS, - .u = - { .copy_segments = from } } ); - n = os_write_file(fd, ©, sizeof(copy)); - if(n != sizeof(copy)) - printk("new_mm : /proc/mm copy_segments failed, " - "err = %d\n", -n); - } - if(skas_needs_stub) map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack); diff --git a/arch/um/sys-i386/ldt.c b/arch/um/sys-i386/ldt.c index 17746b4c08f..0cdfd4481d5 100644 --- a/arch/um/sys-i386/ldt.c +++ b/arch/um/sys-i386/ldt.c @@ -16,6 +16,8 @@ #include "choose-mode.h" #include "kern.h" #include "mode_kern.h" +#include "proc_mm.h" +#include "os.h" extern int modify_ldt(int func, void *ptr, unsigned long bytecount); @@ -456,13 +458,14 @@ long init_new_ldt(struct mmu_context_skas * new_mm, int i; long page, err=0; void *addr = NULL; + struct proc_mm_op copy; - memset(&desc, 0, sizeof(desc)); if(!ptrace_ldt) init_MUTEX(&new_mm->ldt.semaphore); if(!from_mm){ + memset(&desc, 0, sizeof(desc)); /* * We have to initialize a clean ldt. */ @@ -494,8 +497,26 @@ long init_new_ldt(struct mmu_context_skas * new_mm, } } new_mm->ldt.entry_count = 0; + + goto out; } - else if (!ptrace_ldt) { + + if(proc_mm){ + /* We have a valid from_mm, so we now have to copy the LDT of + * from_mm to new_mm, because using proc_mm an new mm with + * an empty/default LDT was created in new_mm() + */ + copy = ((struct proc_mm_op) { .op = MM_COPY_SEGMENTS, + .u = + { .copy_segments = + from_mm->id.u.mm_fd } } ); + i = os_write_file(new_mm->id.u.mm_fd, ©, sizeof(copy)); + if(i != sizeof(copy)) + printk("new_mm : /proc/mm copy_segments failed, " + "err = %d\n", -i); + } + + if(!ptrace_ldt) { /* Our local LDT is used to supply the data for * modify_ldt(READLDT), if PTRACE_LDT isn't available, * i.e., we have to use the stub for modify_ldt, which @@ -524,6 +545,7 @@ long init_new_ldt(struct mmu_context_skas * new_mm, up(&from_mm->ldt.semaphore); } + out: return err; }