[PATCH] uml: maintain own LDT entries
Patch imlements full LDT handling in SKAS: * UML holds it's own LDT table, used to deliver data on modify_ldt(READ) * UML disables the default_ldt, inherited from the host (SKAS3) or resets LDT entries, set by host's clib and inherited in SKAS0 * A new global variable skas_needs_stub is inserted, that can be used to decide, whether stub-pages must be supported or not. * Uses the syscall-stub to replace missing PTRACE_LDT (therefore, write_ldt_entry needs to be modified) Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Bodo Stroesser
Linus Torvalds
parent
e763b793f7
commit
858259cf7d
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@ -8,6 +8,7 @@
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#include "linux/config.h"
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#include "mm_id.h"
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#include "asm/ldt.h"
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struct mmu_context_skas {
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struct mm_id id;
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@ -15,6 +16,7 @@ struct mmu_context_skas {
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#ifdef CONFIG_3_LEVEL_PGTABLES
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unsigned long last_pmd;
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#endif
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uml_ldt_t ldt;
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};
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extern void switch_mm_skas(struct mm_id * mm_idp);
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@ -10,7 +10,8 @@
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#include "sysdep/ptrace.h"
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extern int userspace_pid[];
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extern int proc_mm, ptrace_faultinfo;
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extern int proc_mm, ptrace_faultinfo, ptrace_ldt;
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extern int skas_needs_stub;
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extern void switch_threads(void *me, void *next);
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extern void thread_wait(void *sw, void *fb);
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@ -20,7 +20,7 @@ unsigned long set_task_sizes_skas(int arg, unsigned long *host_size_out,
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*task_size_out = CONFIG_HOST_TASK_SIZE;
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#else
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*host_size_out = top;
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if (proc_mm && ptrace_faultinfo)
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if (!skas_needs_stub)
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*task_size_out = top;
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else *task_size_out = CONFIG_STUB_START & PGDIR_MASK;
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#endif
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@ -15,6 +15,7 @@
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#include "asm/mmu.h"
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#include "asm/pgalloc.h"
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#include "asm/pgtable.h"
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#include "asm/ldt.h"
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#include "os.h"
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#include "skas.h"
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@ -74,13 +75,12 @@ static int init_stub_pte(struct mm_struct *mm, unsigned long proc,
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int init_new_context_skas(struct task_struct *task, struct mm_struct *mm)
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{
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struct mm_struct *cur_mm = current->mm;
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struct mm_id *cur_mm_id = &cur_mm->context.skas.id;
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struct mm_id *mm_id = &mm->context.skas.id;
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struct mmu_context_skas *from_mm = NULL;
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struct mmu_context_skas *to_mm = &mm->context.skas;
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unsigned long stack = 0;
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int from, ret = -ENOMEM;
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int from_fd, ret = -ENOMEM;
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if(!proc_mm || !ptrace_faultinfo){
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if(skas_needs_stub){
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stack = get_zeroed_page(GFP_KERNEL);
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if(stack == 0)
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goto out;
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@ -102,33 +102,43 @@ int init_new_context_skas(struct task_struct *task, struct mm_struct *mm)
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mm->nr_ptes--;
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}
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mm_id->stack = stack;
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to_mm->id.stack = stack;
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if(current->mm != NULL && current->mm != &init_mm)
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from_mm = ¤t->mm->context.skas;
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if(proc_mm){
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if((cur_mm != NULL) && (cur_mm != &init_mm))
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from = cur_mm_id->u.mm_fd;
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else from = -1;
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if(from_mm)
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from_fd = from_mm->id.u.mm_fd;
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else from_fd = -1;
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ret = new_mm(from, stack);
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ret = new_mm(from_fd, stack);
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if(ret < 0){
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printk("init_new_context_skas - new_mm failed, "
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"errno = %d\n", ret);
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goto out_free;
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}
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mm_id->u.mm_fd = ret;
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to_mm->id.u.mm_fd = ret;
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}
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else {
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if((cur_mm != NULL) && (cur_mm != &init_mm))
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mm_id->u.pid = copy_context_skas0(stack,
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cur_mm_id->u.pid);
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else mm_id->u.pid = start_userspace(stack);
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if(from_mm)
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to_mm->id.u.pid = copy_context_skas0(stack,
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from_mm->id.u.pid);
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else to_mm->id.u.pid = start_userspace(stack);
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}
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ret = init_new_ldt(to_mm, from_mm);
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if(ret < 0){
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printk("init_new_context_skas - init_ldt"
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" failed, errno = %d\n", ret);
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goto out_free;
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}
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return 0;
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out_free:
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if(mm_id->stack != 0)
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free_page(mm_id->stack);
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if(to_mm->id.stack != 0)
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free_page(to_mm->id.stack);
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out:
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return ret;
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}
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@ -381,9 +381,9 @@ int copy_context_skas0(unsigned long new_stack, int pid)
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}
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/*
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* This is used only, if proc_mm is available, while PTRACE_FAULTINFO
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* isn't. Opening /proc/mm creates a new mm_context, which lacks the stub-pages
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* Thus, we map them using /proc/mm-fd
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* This is used only, if stub pages are needed, while proc_mm is
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* availabl. Opening /proc/mm creates a new mm_context, which lacks
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* the stub-pages. Thus, we map them using /proc/mm-fd
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*/
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void map_stub_pages(int fd, unsigned long code,
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unsigned long data, unsigned long stack)
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@ -145,7 +145,7 @@ int new_mm(int from, unsigned long stack)
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"err = %d\n", -n);
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}
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if(!ptrace_faultinfo)
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if(skas_needs_stub)
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map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
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return(fd);
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@ -135,7 +135,9 @@ static int stop_ptraced_child(int pid, void *stack, int exitcode,
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}
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int ptrace_faultinfo = 1;
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int ptrace_ldt = 1;
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int proc_mm = 1;
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int skas_needs_stub = 0;
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static int __init skas0_cmd_param(char *str, int* add)
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{
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@ -352,14 +354,26 @@ __uml_setup("noptracefaultinfo", noptracefaultinfo_cmd_param,
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" it. To support PTRACE_FAULTINFO, the host needs to be patched\n"
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" using the current skas3 patch.\n\n");
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static int __init noptraceldt_cmd_param(char *str, int* add)
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{
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ptrace_ldt = 0;
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return 0;
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}
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__uml_setup("noptraceldt", noptraceldt_cmd_param,
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"noptraceldt\n"
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" Turns off usage of PTRACE_LDT, even if host supports it.\n"
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" To support PTRACE_LDT, the host needs to be patched using\n"
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" the current skas3 patch.\n\n");
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#ifdef UML_CONFIG_MODE_SKAS
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static inline void check_skas3_ptrace_support(void)
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static inline void check_skas3_ptrace_faultinfo(void)
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{
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struct ptrace_faultinfo fi;
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void *stack;
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int pid, n;
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printf("Checking for the skas3 patch in the host...");
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printf(" - PTRACE_FAULTINFO...");
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pid = start_ptraced_child(&stack);
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n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi);
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@ -381,9 +395,49 @@ static inline void check_skas3_ptrace_support(void)
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stop_ptraced_child(pid, stack, 1, 1);
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}
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int can_do_skas(void)
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static inline void check_skas3_ptrace_ldt(void)
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{
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printf("Checking for /proc/mm...");
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#ifdef PTRACE_LDT
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void *stack;
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int pid, n;
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unsigned char ldtbuf[40];
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struct ptrace_ldt ldt_op = (struct ptrace_ldt) {
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.func = 2, /* read default ldt */
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.ptr = ldtbuf,
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.bytecount = sizeof(ldtbuf)};
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printf(" - PTRACE_LDT...");
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pid = start_ptraced_child(&stack);
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n = ptrace(PTRACE_LDT, pid, 0, (unsigned long) &ldt_op);
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if (n < 0) {
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if(errno == EIO)
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printf("not found\n");
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else {
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perror("not found");
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}
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ptrace_ldt = 0;
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}
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else {
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if(ptrace_ldt)
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printf("found\n");
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else
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printf("found, but use is disabled\n");
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}
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stop_ptraced_child(pid, stack, 1, 1);
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#else
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/* PTRACE_LDT might be disabled via cmdline option.
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* We want to override this, else we might use the stub
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* without real need
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*/
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ptrace_ldt = 1;
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#endif
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}
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static inline void check_skas3_proc_mm(void)
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{
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printf(" - /proc/mm...");
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if (os_access("/proc/mm", OS_ACC_W_OK) < 0) {
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proc_mm = 0;
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printf("not found\n");
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@ -394,8 +448,19 @@ int can_do_skas(void)
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else
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printf("found\n");
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}
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}
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int can_do_skas(void)
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{
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printf("Checking for the skas3 patch in the host:\n");
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check_skas3_proc_mm();
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check_skas3_ptrace_faultinfo();
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check_skas3_ptrace_ldt();
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if(!proc_mm || !ptrace_faultinfo || !ptrace_ldt)
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skas_needs_stub = 1;
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check_skas3_ptrace_support();
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return 1;
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}
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#else
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@ -26,8 +26,13 @@ define unprofile
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$(patsubst -pg,,$(patsubst -fprofile-arcs -ftest-coverage,,$(1)))
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endef
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# cmd_make_link checks to see if the $(foo-dir) variable starts with a /. If
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# so, it's considered to be a path relative to $(srcdir) rather than
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# $(srcdir)/arch/$(SUBARCH). This is because x86_64 wants to get ldt.c from
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# arch/um/sys-i386 rather than arch/i386 like the other borrowed files. So,
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# it sets $(ldt.c-dir) to /arch/um/sys-i386.
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quiet_cmd_make_link = SYMLINK $@
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cmd_make_link = ln -sf $(srctree)/arch/$(SUBARCH)/$($(notdir $@)-dir)/$(notdir $@) $@
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cmd_make_link = rm -f $@; ln -sf $(srctree)$(if $(filter-out /%,$($(notdir $@)-dir)),/arch/$(SUBARCH))/$($(notdir $@)-dir)/$(notdir $@) $@
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# this needs to be before the foreach, because targets does not accept
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# complete paths like $(obj)/$(f). To make sure this works, use a := assignment
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@ -3,53 +3,26 @@
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* Licensed under the GPL
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*/
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#include "linux/stddef.h"
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#include "linux/config.h"
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#include "linux/sched.h"
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#include "linux/slab.h"
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#include "linux/types.h"
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#include "linux/errno.h"
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#include "asm/uaccess.h"
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#include "asm/ptrace.h"
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#include "asm/smp.h"
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#include "asm/ldt.h"
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#include "asm/unistd.h"
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#include "choose-mode.h"
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#include "kern.h"
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#include "mode_kern.h"
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#ifdef CONFIG_MODE_TT
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extern int modify_ldt(int func, void *ptr, unsigned long bytecount);
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static int do_modify_ldt_tt(int func, void *ptr, unsigned long bytecount)
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{
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return modify_ldt(func, ptr, bytecount);
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}
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#ifdef CONFIG_MODE_TT
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#endif
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#ifdef CONFIG_MODE_SKAS
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#include "skas.h"
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#include "skas_ptrace.h"
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static int do_modify_ldt_skas(int func, void *ptr, unsigned long bytecount)
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{
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struct ptrace_ldt ldt;
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u32 cpu;
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int res;
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ldt = ((struct ptrace_ldt) { .func = func,
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.ptr = ptr,
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.bytecount = bytecount });
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cpu = get_cpu();
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res = ptrace(PTRACE_LDT, userspace_pid[cpu], 0, (unsigned long) &ldt);
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put_cpu();
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return res;
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}
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#endif
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int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount)
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static long do_modify_ldt_tt(int func, void __user *ptr,
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unsigned long bytecount)
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{
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struct user_desc info;
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int res = 0;
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@ -89,8 +62,7 @@ int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount)
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goto out;
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}
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res = CHOOSE_MODE_PROC(do_modify_ldt_tt, do_modify_ldt_skas, func,
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p, bytecount);
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res = modify_ldt(func, p, bytecount);
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if(res < 0)
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goto out;
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@ -108,3 +80,467 @@ out:
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kfree(buf);
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return res;
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}
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#endif
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#ifdef CONFIG_MODE_SKAS
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#include "skas.h"
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#include "skas_ptrace.h"
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#include "asm/mmu_context.h"
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long write_ldt_entry(struct mm_id * mm_idp, int func, struct user_desc * desc,
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void **addr, int done)
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{
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long res;
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if(proc_mm){
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/* This is a special handling for the case, that the mm to
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* modify isn't current->active_mm.
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* If this is called directly by modify_ldt,
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* (current->active_mm->context.skas.u == mm_idp)
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* will be true. So no call to switch_mm_skas(mm_idp) is done.
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* If this is called in case of init_new_ldt or PTRACE_LDT,
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* mm_idp won't belong to current->active_mm, but child->mm.
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* So we need to switch child's mm into our userspace, then
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* later switch back.
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*
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* Note: I'm unshure: should interrupts be disabled here?
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*/
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if(!current->active_mm || current->active_mm == &init_mm ||
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mm_idp != ¤t->active_mm->context.skas.id)
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switch_mm_skas(mm_idp);
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}
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if(ptrace_ldt) {
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struct ptrace_ldt ldt_op = (struct ptrace_ldt) {
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.func = func,
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.ptr = desc,
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.bytecount = sizeof(*desc)};
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u32 cpu;
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int pid;
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if(!proc_mm)
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pid = mm_idp->u.pid;
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else {
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cpu = get_cpu();
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pid = userspace_pid[cpu];
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}
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res = ptrace(PTRACE_LDT, pid, 0, (unsigned long) &ldt_op);
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if(res)
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res = errno;
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if(proc_mm)
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put_cpu();
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}
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else {
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void *stub_addr;
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res = syscall_stub_data(mm_idp, (unsigned long *)desc,
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(sizeof(*desc) + sizeof(long) - 1) &
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~(sizeof(long) - 1),
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addr, &stub_addr);
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if(!res){
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unsigned long args[] = { func,
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(unsigned long)stub_addr,
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sizeof(*desc),
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0, 0, 0 };
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res = run_syscall_stub(mm_idp, __NR_modify_ldt, args,
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0, addr, done);
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}
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}
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if(proc_mm){
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/* This is the second part of special handling, that makes
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* PTRACE_LDT possible to implement.
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*/
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if(current->active_mm && current->active_mm != &init_mm &&
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mm_idp != ¤t->active_mm->context.skas.id)
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switch_mm_skas(¤t->active_mm->context.skas.id);
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}
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return res;
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}
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static long read_ldt_from_host(void __user * ptr, unsigned long bytecount)
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{
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int res, n;
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struct ptrace_ldt ptrace_ldt = (struct ptrace_ldt) {
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.func = 0,
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.bytecount = bytecount,
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.ptr = (void *)kmalloc(bytecount, GFP_KERNEL)};
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u32 cpu;
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if(ptrace_ldt.ptr == NULL)
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return -ENOMEM;
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/* This is called from sys_modify_ldt only, so userspace_pid gives
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* us the right number
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*/
|
||||
|
||||
cpu = get_cpu();
|
||||
res = ptrace(PTRACE_LDT, userspace_pid[cpu], 0,
|
||||
(unsigned long) &ptrace_ldt);
|
||||
put_cpu();
|
||||
if(res < 0)
|
||||
goto out;
|
||||
|
||||
n = copy_to_user(ptr, ptrace_ldt.ptr, res);
|
||||
if(n != 0)
|
||||
res = -EFAULT;
|
||||
|
||||
out:
|
||||
kfree(ptrace_ldt.ptr);
|
||||
|
||||
return res;
|
||||
}
|
||||
|
||||
/*
|
||||
* In skas mode, we hold our own ldt data in UML.
|
||||
* Thus, the code implementing sys_modify_ldt_skas
|
||||
* is very similar to (and mostly stolen from) sys_modify_ldt
|
||||
* for arch/i386/kernel/ldt.c
|
||||
* The routines copied and modified in part are:
|
||||
* - read_ldt
|
||||
* - read_default_ldt
|
||||
* - write_ldt
|
||||
* - sys_modify_ldt_skas
|
||||
*/
|
||||
|
||||
static int read_ldt(void __user * ptr, unsigned long bytecount)
|
||||
{
|
||||
int i, err = 0;
|
||||
unsigned long size;
|
||||
uml_ldt_t * ldt = ¤t->mm->context.skas.ldt;
|
||||
|
||||
if(!ldt->entry_count)
|
||||
goto out;
|
||||
if(bytecount > LDT_ENTRY_SIZE*LDT_ENTRIES)
|
||||
bytecount = LDT_ENTRY_SIZE*LDT_ENTRIES;
|
||||
err = bytecount;
|
||||
|
||||
if(ptrace_ldt){
|
||||
return read_ldt_from_host(ptr, bytecount);
|
||||
}
|
||||
|
||||
down(&ldt->semaphore);
|
||||
if(ldt->entry_count <= LDT_DIRECT_ENTRIES){
|
||||
size = LDT_ENTRY_SIZE*LDT_DIRECT_ENTRIES;
|
||||
if(size > bytecount)
|
||||
size = bytecount;
|
||||
if(copy_to_user(ptr, ldt->entries, size))
|
||||
err = -EFAULT;
|
||||
bytecount -= size;
|
||||
ptr += size;
|
||||
}
|
||||
else {
|
||||
for(i=0; i<ldt->entry_count/LDT_ENTRIES_PER_PAGE && bytecount;
|
||||
i++){
|
||||
size = PAGE_SIZE;
|
||||
if(size > bytecount)
|
||||
size = bytecount;
|
||||
if(copy_to_user(ptr, ldt->pages[i], size)){
|
||||
err = -EFAULT;
|
||||
break;
|
||||
}
|
||||
bytecount -= size;
|
||||
ptr += size;
|
||||
}
|
||||
}
|
||||
up(&ldt->semaphore);
|
||||
|
||||
if(bytecount == 0 || err == -EFAULT)
|
||||
goto out;
|
||||
|
||||
if(clear_user(ptr, bytecount))
|
||||
err = -EFAULT;
|
||||
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
static int read_default_ldt(void __user * ptr, unsigned long bytecount)
|
||||
{
|
||||
int err;
|
||||
|
||||
if(bytecount > 5*LDT_ENTRY_SIZE)
|
||||
bytecount = 5*LDT_ENTRY_SIZE;
|
||||
|
||||
err = bytecount;
|
||||
/* UML doesn't support lcall7 and lcall27.
|
||||
* So, we don't really have a default ldt, but emulate
|
||||
* an empty ldt of common host default ldt size.
|
||||
*/
|
||||
if(clear_user(ptr, bytecount))
|
||||
err = -EFAULT;
|
||||
|
||||
return err;
|
||||
}
|
||||
|
||||
static int write_ldt(void __user * ptr, unsigned long bytecount, int func)
|
||||
{
|
||||
uml_ldt_t * ldt = ¤t->mm->context.skas.ldt;
|
||||
struct mm_id * mm_idp = ¤t->mm->context.skas.id;
|
||||
int i, err;
|
||||
struct user_desc ldt_info;
|
||||
struct ldt_entry entry0, *ldt_p;
|
||||
void *addr = NULL;
|
||||
|
||||
err = -EINVAL;
|
||||
if(bytecount != sizeof(ldt_info))
|
||||
goto out;
|
||||
err = -EFAULT;
|
||||
if(copy_from_user(&ldt_info, ptr, sizeof(ldt_info)))
|
||||
goto out;
|
||||
|
||||
err = -EINVAL;
|
||||
if(ldt_info.entry_number >= LDT_ENTRIES)
|
||||
goto out;
|
||||
if(ldt_info.contents == 3){
|
||||
if (func == 1)
|
||||
goto out;
|
||||
if (ldt_info.seg_not_present == 0)
|
||||
goto out;
|
||||
}
|
||||
|
||||
if(!ptrace_ldt)
|
||||
down(&ldt->semaphore);
|
||||
|
||||
err = write_ldt_entry(mm_idp, func, &ldt_info, &addr, 1);
|
||||
if(err)
|
||||
goto out_unlock;
|
||||
else if(ptrace_ldt) {
|
||||
/* With PTRACE_LDT available, this is used as a flag only */
|
||||
ldt->entry_count = 1;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if(ldt_info.entry_number >= ldt->entry_count &&
|
||||
ldt_info.entry_number >= LDT_DIRECT_ENTRIES){
|
||||
for(i=ldt->entry_count/LDT_ENTRIES_PER_PAGE;
|
||||
i*LDT_ENTRIES_PER_PAGE <= ldt_info.entry_number;
|
||||
i++){
|
||||
if(i == 0)
|
||||
memcpy(&entry0, ldt->entries, sizeof(entry0));
|
||||
ldt->pages[i] = (struct ldt_entry *)
|
||||
__get_free_page(GFP_KERNEL|__GFP_ZERO);
|
||||
if(!ldt->pages[i]){
|
||||
err = -ENOMEM;
|
||||
/* Undo the change in host */
|
||||
memset(&ldt_info, 0, sizeof(ldt_info));
|
||||
write_ldt_entry(mm_idp, 1, &ldt_info, &addr, 1);
|
||||
goto out_unlock;
|
||||
}
|
||||
if(i == 0) {
|
||||
memcpy(ldt->pages[0], &entry0, sizeof(entry0));
|
||||
memcpy(ldt->pages[0]+1, ldt->entries+1,
|
||||
sizeof(entry0)*(LDT_DIRECT_ENTRIES-1));
|
||||
}
|
||||
ldt->entry_count = (i + 1) * LDT_ENTRIES_PER_PAGE;
|
||||
}
|
||||
}
|
||||
if(ldt->entry_count <= ldt_info.entry_number)
|
||||
ldt->entry_count = ldt_info.entry_number + 1;
|
||||
|
||||
if(ldt->entry_count <= LDT_DIRECT_ENTRIES)
|
||||
ldt_p = ldt->entries + ldt_info.entry_number;
|
||||
else
|
||||
ldt_p = ldt->pages[ldt_info.entry_number/LDT_ENTRIES_PER_PAGE] +
|
||||
ldt_info.entry_number%LDT_ENTRIES_PER_PAGE;
|
||||
|
||||
if(ldt_info.base_addr == 0 && ldt_info.limit == 0 &&
|
||||
(func == 1 || LDT_empty(&ldt_info))){
|
||||
ldt_p->a = 0;
|
||||
ldt_p->b = 0;
|
||||
}
|
||||
else{
|
||||
if (func == 1)
|
||||
ldt_info.useable = 0;
|
||||
ldt_p->a = LDT_entry_a(&ldt_info);
|
||||
ldt_p->b = LDT_entry_b(&ldt_info);
|
||||
}
|
||||
err = 0;
|
||||
|
||||
out_unlock:
|
||||
up(&ldt->semaphore);
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
static long do_modify_ldt_skas(int func, void __user *ptr,
|
||||
unsigned long bytecount)
|
||||
{
|
||||
int ret = -ENOSYS;
|
||||
|
||||
switch (func) {
|
||||
case 0:
|
||||
ret = read_ldt(ptr, bytecount);
|
||||
break;
|
||||
case 1:
|
||||
case 0x11:
|
||||
ret = write_ldt(ptr, bytecount, func);
|
||||
break;
|
||||
case 2:
|
||||
ret = read_default_ldt(ptr, bytecount);
|
||||
break;
|
||||
}
|
||||
return ret;
|
||||
}
|
||||
|
||||
short dummy_list[9] = {0, -1};
|
||||
short * host_ldt_entries = NULL;
|
||||
|
||||
void ldt_get_host_info(void)
|
||||
{
|
||||
long ret;
|
||||
struct ldt_entry * ldt;
|
||||
int i, size, k, order;
|
||||
|
||||
host_ldt_entries = dummy_list+1;
|
||||
|
||||
for(i = LDT_PAGES_MAX-1, order=0; i; i>>=1, order++);
|
||||
|
||||
ldt = (struct ldt_entry *)
|
||||
__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
|
||||
if(ldt == NULL) {
|
||||
printk("ldt_get_host_info: couldn't allocate buffer for host ldt\n");
|
||||
return;
|
||||
}
|
||||
|
||||
ret = modify_ldt(0, ldt, (1<<order)*PAGE_SIZE);
|
||||
if(ret < 0) {
|
||||
printk("ldt_get_host_info: couldn't read host ldt\n");
|
||||
goto out_free;
|
||||
}
|
||||
if(ret == 0) {
|
||||
/* default_ldt is active, simply write an empty entry 0 */
|
||||
host_ldt_entries = dummy_list;
|
||||
goto out_free;
|
||||
}
|
||||
|
||||
for(i=0, size=0; i<ret/LDT_ENTRY_SIZE; i++){
|
||||
if(ldt[i].a != 0 || ldt[i].b != 0)
|
||||
size++;
|
||||
}
|
||||
|
||||
if(size < sizeof(dummy_list)/sizeof(dummy_list[0])) {
|
||||
host_ldt_entries = dummy_list;
|
||||
}
|
||||
else {
|
||||
size = (size + 1) * sizeof(dummy_list[0]);
|
||||
host_ldt_entries = (short *)kmalloc(size, GFP_KERNEL);
|
||||
if(host_ldt_entries == NULL) {
|
||||
printk("ldt_get_host_info: couldn't allocate host ldt list\n");
|
||||
goto out_free;
|
||||
}
|
||||
}
|
||||
|
||||
for(i=0, k=0; i<ret/LDT_ENTRY_SIZE; i++){
|
||||
if(ldt[i].a != 0 || ldt[i].b != 0) {
|
||||
host_ldt_entries[k++] = i;
|
||||
}
|
||||
}
|
||||
host_ldt_entries[k] = -1;
|
||||
|
||||
out_free:
|
||||
free_pages((unsigned long)ldt, order);
|
||||
}
|
||||
|
||||
long init_new_ldt(struct mmu_context_skas * new_mm,
|
||||
struct mmu_context_skas * from_mm)
|
||||
{
|
||||
struct user_desc desc;
|
||||
short * num_p;
|
||||
int i;
|
||||
long page, err=0;
|
||||
void *addr = NULL;
|
||||
|
||||
memset(&desc, 0, sizeof(desc));
|
||||
|
||||
if(!ptrace_ldt)
|
||||
init_MUTEX(&new_mm->ldt.semaphore);
|
||||
|
||||
if(!from_mm){
|
||||
/*
|
||||
* We have to initialize a clean ldt.
|
||||
*/
|
||||
if(proc_mm) {
|
||||
/*
|
||||
* If the new mm was created using proc_mm, host's
|
||||
* default-ldt currently is assigned, which normally
|
||||
* contains the call-gates for lcall7 and lcall27.
|
||||
* To remove these gates, we simply write an empty
|
||||
* entry as number 0 to the host.
|
||||
*/
|
||||
err = write_ldt_entry(&new_mm->id, 1, &desc,
|
||||
&addr, 1);
|
||||
}
|
||||
else{
|
||||
/*
|
||||
* Now we try to retrieve info about the ldt, we
|
||||
* inherited from the host. All ldt-entries found
|
||||
* will be reset in the following loop
|
||||
*/
|
||||
if(host_ldt_entries == NULL)
|
||||
ldt_get_host_info();
|
||||
for(num_p=host_ldt_entries; *num_p != -1; num_p++){
|
||||
desc.entry_number = *num_p;
|
||||
err = write_ldt_entry(&new_mm->id, 1, &desc,
|
||||
&addr, *(num_p + 1) == -1);
|
||||
if(err)
|
||||
break;
|
||||
}
|
||||
}
|
||||
new_mm->ldt.entry_count = 0;
|
||||
}
|
||||
else 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
|
||||
* can't handle the big read buffer of up to 64kB.
|
||||
*/
|
||||
down(&from_mm->ldt.semaphore);
|
||||
if(from_mm->ldt.entry_count <= LDT_DIRECT_ENTRIES){
|
||||
memcpy(new_mm->ldt.entries, from_mm->ldt.entries,
|
||||
sizeof(new_mm->ldt.entries));
|
||||
}
|
||||
else{
|
||||
i = from_mm->ldt.entry_count / LDT_ENTRIES_PER_PAGE;
|
||||
while(i-->0){
|
||||
page = __get_free_page(GFP_KERNEL|__GFP_ZERO);
|
||||
if (!page){
|
||||
err = -ENOMEM;
|
||||
break;
|
||||
}
|
||||
new_mm->ldt.pages[i] = (struct ldt_entry*)page;
|
||||
memcpy(new_mm->ldt.pages[i],
|
||||
from_mm->ldt.pages[i], PAGE_SIZE);
|
||||
}
|
||||
}
|
||||
new_mm->ldt.entry_count = from_mm->ldt.entry_count;
|
||||
up(&from_mm->ldt.semaphore);
|
||||
}
|
||||
|
||||
return err;
|
||||
}
|
||||
|
||||
|
||||
void free_ldt(struct mmu_context_skas * mm)
|
||||
{
|
||||
int i;
|
||||
|
||||
if(!ptrace_ldt && mm->ldt.entry_count > LDT_DIRECT_ENTRIES){
|
||||
i = mm->ldt.entry_count / LDT_ENTRIES_PER_PAGE;
|
||||
while(i-- > 0){
|
||||
free_page((long )mm->ldt.pages[i]);
|
||||
}
|
||||
}
|
||||
mm->ldt.entry_count = 0;
|
||||
}
|
||||
#endif
|
||||
|
||||
int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount)
|
||||
{
|
||||
return(CHOOSE_MODE_PROC(do_modify_ldt_tt, do_modify_ldt_skas, func,
|
||||
ptr, bytecount));
|
||||
}
|
||||
|
|
|
|||
|
|
@ -5,7 +5,7 @@
|
|||
#
|
||||
|
||||
#XXX: why into lib-y?
|
||||
lib-y = bitops.o bugs.o csum-partial.o delay.o fault.o mem.o memcpy.o \
|
||||
lib-y = bitops.o bugs.o csum-partial.o delay.o fault.o ldt.o mem.o memcpy.o \
|
||||
ptrace.o ptrace_user.o sigcontext.o signal.o stub.o \
|
||||
stub_segv.o syscalls.o syscall_table.o sysrq.o thunk.o
|
||||
|
||||
|
|
@ -14,7 +14,7 @@ obj-$(CONFIG_MODULES) += module.o um_module.o
|
|||
|
||||
USER_OBJS := ptrace_user.o sigcontext.o
|
||||
|
||||
SYMLINKS = bitops.c csum-copy.S csum-partial.c csum-wrappers.c memcpy.S \
|
||||
SYMLINKS = bitops.c csum-copy.S csum-partial.c csum-wrappers.c ldt.c memcpy.S \
|
||||
thunk.S module.c
|
||||
|
||||
include arch/um/scripts/Makefile.rules
|
||||
|
|
@ -23,6 +23,7 @@ bitops.c-dir = lib
|
|||
csum-copy.S-dir = lib
|
||||
csum-partial.c-dir = lib
|
||||
csum-wrappers.c-dir = lib
|
||||
ldt.c-dir = /arch/um/sys-i386
|
||||
memcpy.S-dir = lib
|
||||
thunk.S-dir = lib
|
||||
module.c-dir = kernel
|
||||
|
|
|
|||
|
|
@ -28,81 +28,6 @@ asmlinkage long sys_uname64(struct new_utsname __user * name)
|
|||
return err ? -EFAULT : 0;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_MODE_TT
|
||||
extern int modify_ldt(int func, void *ptr, unsigned long bytecount);
|
||||
|
||||
long sys_modify_ldt_tt(int func, void *ptr, unsigned long bytecount)
|
||||
{
|
||||
/* XXX This should check VERIFY_WRITE depending on func, check this
|
||||
* in i386 as well.
|
||||
*/
|
||||
if (!access_ok(VERIFY_READ, ptr, bytecount))
|
||||
return -EFAULT;
|
||||
return(modify_ldt(func, ptr, bytecount));
|
||||
}
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_MODE_SKAS
|
||||
extern int userspace_pid[];
|
||||
|
||||
#include "skas_ptrace.h"
|
||||
|
||||
long sys_modify_ldt_skas(int func, void *ptr, unsigned long bytecount)
|
||||
{
|
||||
struct ptrace_ldt ldt;
|
||||
void *buf;
|
||||
int res, n;
|
||||
|
||||
buf = kmalloc(bytecount, GFP_KERNEL);
|
||||
if(buf == NULL)
|
||||
return(-ENOMEM);
|
||||
|
||||
res = 0;
|
||||
|
||||
switch(func){
|
||||
case 1:
|
||||
case 0x11:
|
||||
res = copy_from_user(buf, ptr, bytecount);
|
||||
break;
|
||||
}
|
||||
|
||||
if(res != 0){
|
||||
res = -EFAULT;
|
||||
goto out;
|
||||
}
|
||||
|
||||
ldt = ((struct ptrace_ldt) { .func = func,
|
||||
.ptr = buf,
|
||||
.bytecount = bytecount });
|
||||
#warning Need to look up userspace_pid by cpu
|
||||
res = ptrace(PTRACE_LDT, userspace_pid[0], 0, (unsigned long) &ldt);
|
||||
if(res < 0)
|
||||
goto out;
|
||||
|
||||
switch(func){
|
||||
case 0:
|
||||
case 2:
|
||||
n = res;
|
||||
res = copy_to_user(ptr, buf, n);
|
||||
if(res != 0)
|
||||
res = -EFAULT;
|
||||
else
|
||||
res = n;
|
||||
break;
|
||||
}
|
||||
|
||||
out:
|
||||
kfree(buf);
|
||||
return(res);
|
||||
}
|
||||
#endif
|
||||
|
||||
long sys_modify_ldt(int func, void *ptr, unsigned long bytecount)
|
||||
{
|
||||
return(CHOOSE_MODE_PROC(sys_modify_ldt_tt, sys_modify_ldt_skas, func,
|
||||
ptr, bytecount));
|
||||
}
|
||||
|
||||
#ifdef CONFIG_MODE_TT
|
||||
extern long arch_prctl(int code, unsigned long addr);
|
||||
|
||||
|
|
|
|||
|
|
@ -0,0 +1,69 @@
|
|||
/*
|
||||
* Copyright (C) 2004 Fujitsu Siemens Computers GmbH
|
||||
* Licensed under the GPL
|
||||
*
|
||||
* Author: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
|
||||
*/
|
||||
|
||||
#ifndef __ASM_LDT_I386_H
|
||||
#define __ASM_LDT_I386_H
|
||||
|
||||
#include "asm/semaphore.h"
|
||||
#include "asm/arch/ldt.h"
|
||||
|
||||
struct mmu_context_skas;
|
||||
extern void ldt_host_info(void);
|
||||
extern long init_new_ldt(struct mmu_context_skas * to_mm,
|
||||
struct mmu_context_skas * from_mm);
|
||||
extern void free_ldt(struct mmu_context_skas * mm);
|
||||
|
||||
#define LDT_PAGES_MAX \
|
||||
((LDT_ENTRIES * LDT_ENTRY_SIZE)/PAGE_SIZE)
|
||||
#define LDT_ENTRIES_PER_PAGE \
|
||||
(PAGE_SIZE/LDT_ENTRY_SIZE)
|
||||
#define LDT_DIRECT_ENTRIES \
|
||||
((LDT_PAGES_MAX*sizeof(void *))/LDT_ENTRY_SIZE)
|
||||
|
||||
struct ldt_entry {
|
||||
__u32 a;
|
||||
__u32 b;
|
||||
};
|
||||
|
||||
typedef struct uml_ldt {
|
||||
int entry_count;
|
||||
struct semaphore semaphore;
|
||||
union {
|
||||
struct ldt_entry * pages[LDT_PAGES_MAX];
|
||||
struct ldt_entry entries[LDT_DIRECT_ENTRIES];
|
||||
};
|
||||
} uml_ldt_t;
|
||||
|
||||
/*
|
||||
* macros stolen from include/asm-i386/desc.h
|
||||
*/
|
||||
#define LDT_entry_a(info) \
|
||||
((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
|
||||
|
||||
#define LDT_entry_b(info) \
|
||||
(((info)->base_addr & 0xff000000) | \
|
||||
(((info)->base_addr & 0x00ff0000) >> 16) | \
|
||||
((info)->limit & 0xf0000) | \
|
||||
(((info)->read_exec_only ^ 1) << 9) | \
|
||||
((info)->contents << 10) | \
|
||||
(((info)->seg_not_present ^ 1) << 15) | \
|
||||
((info)->seg_32bit << 22) | \
|
||||
((info)->limit_in_pages << 23) | \
|
||||
((info)->useable << 20) | \
|
||||
0x7000)
|
||||
|
||||
#define LDT_empty(info) (\
|
||||
(info)->base_addr == 0 && \
|
||||
(info)->limit == 0 && \
|
||||
(info)->contents == 0 && \
|
||||
(info)->read_exec_only == 1 && \
|
||||
(info)->seg_32bit == 0 && \
|
||||
(info)->limit_in_pages == 0 && \
|
||||
(info)->seg_not_present == 1 && \
|
||||
(info)->useable == 0 )
|
||||
|
||||
#endif
|
||||
|
|
@ -1,3 +1,72 @@
|
|||
/*
|
||||
* Copyright (C) 2004 Fujitsu Siemens Computers GmbH
|
||||
* Licensed under the GPL
|
||||
*
|
||||
* Author: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
|
||||
*/
|
||||
|
||||
#ifndef __ASM_LDT_I386_H
|
||||
#define __ASM_LDT_I386_H
|
||||
|
||||
#include "asm/semaphore.h"
|
||||
#include "asm/arch/ldt.h"
|
||||
|
||||
struct mmu_context_skas;
|
||||
extern void ldt_host_info(void);
|
||||
extern long init_new_ldt(struct mmu_context_skas * to_mm,
|
||||
struct mmu_context_skas * from_mm);
|
||||
extern void free_ldt(struct mmu_context_skas * mm);
|
||||
|
||||
#define LDT_PAGES_MAX \
|
||||
((LDT_ENTRIES * LDT_ENTRY_SIZE)/PAGE_SIZE)
|
||||
#define LDT_ENTRIES_PER_PAGE \
|
||||
(PAGE_SIZE/LDT_ENTRY_SIZE)
|
||||
#define LDT_DIRECT_ENTRIES \
|
||||
((LDT_PAGES_MAX*sizeof(void *))/LDT_ENTRY_SIZE)
|
||||
|
||||
struct ldt_entry {
|
||||
__u32 a;
|
||||
__u32 b;
|
||||
};
|
||||
|
||||
typedef struct uml_ldt {
|
||||
int entry_count;
|
||||
struct semaphore semaphore;
|
||||
union {
|
||||
struct ldt_entry * pages[LDT_PAGES_MAX];
|
||||
struct ldt_entry entries[LDT_DIRECT_ENTRIES];
|
||||
};
|
||||
} uml_ldt_t;
|
||||
|
||||
/*
|
||||
* macros stolen from include/asm-i386/desc.h
|
||||
*/
|
||||
#define LDT_entry_a(info) \
|
||||
((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
|
||||
|
||||
#define LDT_entry_b(info) \
|
||||
(((info)->base_addr & 0xff000000) | \
|
||||
(((info)->base_addr & 0x00ff0000) >> 16) | \
|
||||
((info)->limit & 0xf0000) | \
|
||||
(((info)->read_exec_only ^ 1) << 9) | \
|
||||
((info)->contents << 10) | \
|
||||
(((info)->seg_not_present ^ 1) << 15) | \
|
||||
((info)->seg_32bit << 22) | \
|
||||
((info)->limit_in_pages << 23) | \
|
||||
((info)->useable << 20) | \
|
||||
0x7000)
|
||||
|
||||
#define LDT_empty(info) (\
|
||||
(info)->base_addr == 0 && \
|
||||
(info)->limit == 0 && \
|
||||
(info)->contents == 0 && \
|
||||
(info)->read_exec_only == 1 && \
|
||||
(info)->seg_32bit == 0 && \
|
||||
(info)->limit_in_pages == 0 && \
|
||||
(info)->seg_not_present == 1 && \
|
||||
(info)->useable == 0 )
|
||||
|
||||
#endif
|
||||
#ifndef __UM_LDT_H
|
||||
#define __UM_LDT_H
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue