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authorbellard <bellard@c046a42c-6fe2-441c-8c8c-71466251a162>2003-03-16 18:05:05 +0000
committerbellard <bellard@c046a42c-6fe2-441c-8c8c-71466251a162>2003-03-16 18:05:05 +0000
commit6dbad63eef5947c6c8750e44f408138779b6d0bb (patch)
treee96572a87e9adb75efde4cd9213472f1903ec742 /linux-user
parent27362c82e9df7770554943ceda36ec4e5638c49d (diff)
downloadqemu-6dbad63eef5947c6c8750e44f408138779b6d0bb.zip
qemu-6dbad63eef5947c6c8750e44f408138779b6d0bb.tar.gz
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added minimal segment support
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@28 c046a42c-6fe2-441c-8c8c-71466251a162
Diffstat (limited to 'linux-user')
-rw-r--r--linux-user/main.c58
-rw-r--r--linux-user/qemu.h2
-rw-r--r--linux-user/syscall.c126
-rw-r--r--linux-user/syscall_types.h1
4 files changed, 163 insertions, 24 deletions
diff --git a/linux-user/main.c b/linux-user/main.c
index 6aefe3a..b59c85d 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -1,5 +1,5 @@
/*
- * emu main
+ * gemu main
*
* Copyright (c) 2003 Fabrice Bellard
*
@@ -80,10 +80,28 @@ int cpu_x86_inl(int addr)
return 0;
}
+/* default linux values for the selectors */
+#define __USER_CS (0x23)
+#define __USER_DS (0x2B)
-/* XXX: currently we use LDT entries */
-#define __USER_CS (0x23|4)
-#define __USER_DS (0x2B|4)
+void write_dt(void *ptr, unsigned long addr, unsigned long limit,
+ int seg32_bit)
+{
+ unsigned int e1, e2, limit_in_pages;
+ limit_in_pages = 0;
+ if (limit > 0xffff) {
+ limit = limit >> 12;
+ limit_in_pages = 1;
+ }
+ e1 = (addr << 16) | (limit & 0xffff);
+ e2 = ((addr >> 16) & 0xff) | (addr & 0xff000000) | (limit & 0x000f0000);
+ e2 |= limit_in_pages << 23; /* byte granularity */
+ e2 |= seg32_bit << 22; /* 32 bit segment */
+ stl((uint8_t *)ptr, e1);
+ stl((uint8_t *)ptr + 4, e2);
+}
+
+uint64_t gdt_table[6];
void usage(void)
{
@@ -94,6 +112,8 @@ void usage(void)
exit(1);
}
+
+
int main(int argc, char **argv)
{
const char *filename;
@@ -149,6 +169,7 @@ int main(int argc, char **argv)
env = cpu_x86_init();
+ /* linux register setup */
env->regs[R_EAX] = regs->eax;
env->regs[R_EBX] = regs->ebx;
env->regs[R_ECX] = regs->ecx;
@@ -157,23 +178,19 @@ int main(int argc, char **argv)
env->regs[R_EDI] = regs->edi;
env->regs[R_EBP] = regs->ebp;
env->regs[R_ESP] = regs->esp;
- env->segs[R_CS] = __USER_CS;
- env->segs[R_DS] = __USER_DS;
- env->segs[R_ES] = __USER_DS;
- env->segs[R_SS] = __USER_DS;
- env->segs[R_FS] = __USER_DS;
- env->segs[R_GS] = __USER_DS;
env->pc = regs->eip;
-#if 0
- LDT[__USER_CS >> 3].w86Flags = DF_PRESENT | DF_PAGES | DF_32;
- LDT[__USER_CS >> 3].dwSelLimit = 0xfffff;
- LDT[__USER_CS >> 3].lpSelBase = NULL;
-
- LDT[__USER_DS >> 3].w86Flags = DF_PRESENT | DF_PAGES | DF_32;
- LDT[__USER_DS >> 3].dwSelLimit = 0xfffff;
- LDT[__USER_DS >> 3].lpSelBase = NULL;
-#endif
+ /* linux segment setup */
+ env->gdt.base = (void *)gdt_table;
+ env->gdt.limit = sizeof(gdt_table) - 1;
+ write_dt(&gdt_table[__USER_CS >> 3], 0, 0xffffffff, 1);
+ write_dt(&gdt_table[__USER_DS >> 3], 0, 0xffffffff, 1);
+ cpu_x86_load_seg(env, R_CS, __USER_CS);
+ cpu_x86_load_seg(env, R_DS, __USER_DS);
+ cpu_x86_load_seg(env, R_ES, __USER_DS);
+ cpu_x86_load_seg(env, R_SS, __USER_DS);
+ cpu_x86_load_seg(env, R_FS, __USER_DS);
+ cpu_x86_load_seg(env, R_GS, __USER_DS);
for(;;) {
int err;
@@ -186,7 +203,8 @@ int main(int argc, char **argv)
if (pc[0] == 0xcd && pc[1] == 0x80) {
/* syscall */
env->pc += 2;
- env->regs[R_EAX] = do_syscall(env->regs[R_EAX],
+ env->regs[R_EAX] = do_syscall(env,
+ env->regs[R_EAX],
env->regs[R_EBX],
env->regs[R_ECX],
env->regs[R_EDX],
diff --git a/linux-user/qemu.h b/linux-user/qemu.h
index 0b9de6b..4f09e6f 100644
--- a/linux-user/qemu.h
+++ b/linux-user/qemu.h
@@ -48,7 +48,7 @@ int elf_exec(const char * filename, char ** argv, char ** envp,
void target_set_brk(char *new_brk);
void syscall_init(void);
-long do_syscall(int num, long arg1, long arg2, long arg3,
+long do_syscall(void *cpu_env, int num, long arg1, long arg2, long arg3,
long arg4, long arg5, long arg6);
void gemu_log(const char *fmt, ...) __attribute__((format(printf,1,2)));
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index ac40cf1..9ed8daa 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -69,6 +69,7 @@ struct dirent {
#include "syscall_defs.h"
#ifdef TARGET_I386
+#include "cpu-i386.h"
#include "syscall-i386.h"
#endif
@@ -607,6 +608,124 @@ StructEntry struct_termios_def = {
.align = { __alignof__(struct target_termios), __alignof__(struct host_termios) },
};
+#ifdef TARGET_I386
+
+/* NOTE: there is really one LDT for all the threads */
+uint8_t *ldt_table;
+
+static int read_ldt(void *ptr, unsigned long bytecount)
+{
+ int size;
+
+ if (!ldt_table)
+ return 0;
+ size = TARGET_LDT_ENTRIES * TARGET_LDT_ENTRY_SIZE;
+ if (size > bytecount)
+ size = bytecount;
+ memcpy(ptr, ldt_table, size);
+ return size;
+}
+
+/* XXX: add locking support */
+static int write_ldt(CPUX86State *env,
+ void *ptr, unsigned long bytecount, int oldmode)
+{
+ struct target_modify_ldt_ldt_s ldt_info;
+ int seg_32bit, contents, read_exec_only, limit_in_pages;
+ int seg_not_present, useable;
+ uint32_t *lp, entry_1, entry_2;
+
+ if (bytecount != sizeof(ldt_info))
+ return -EINVAL;
+ memcpy(&ldt_info, ptr, sizeof(ldt_info));
+ tswap32s(&ldt_info.entry_number);
+ tswapls((long *)&ldt_info.base_addr);
+ tswap32s(&ldt_info.limit);
+ tswap32s(&ldt_info.flags);
+
+ if (ldt_info.entry_number >= TARGET_LDT_ENTRIES)
+ return -EINVAL;
+ seg_32bit = ldt_info.flags & 1;
+ contents = (ldt_info.flags >> 1) & 3;
+ read_exec_only = (ldt_info.flags >> 3) & 1;
+ limit_in_pages = (ldt_info.flags >> 4) & 1;
+ seg_not_present = (ldt_info.flags >> 5) & 1;
+ useable = (ldt_info.flags >> 6) & 1;
+
+ if (contents == 3) {
+ if (oldmode)
+ return -EINVAL;
+ if (seg_not_present == 0)
+ return -EINVAL;
+ }
+ /* allocate the LDT */
+ if (!ldt_table) {
+ ldt_table = malloc(TARGET_LDT_ENTRIES * TARGET_LDT_ENTRY_SIZE);
+ if (!ldt_table)
+ return -ENOMEM;
+ memset(ldt_table, 0, TARGET_LDT_ENTRIES * TARGET_LDT_ENTRY_SIZE);
+ env->ldt.base = ldt_table;
+ env->ldt.limit = 0xffff;
+ }
+
+ /* NOTE: same code as Linux kernel */
+ /* Allow LDTs to be cleared by the user. */
+ if (ldt_info.base_addr == 0 && ldt_info.limit == 0) {
+ if (oldmode ||
+ (contents == 0 &&
+ read_exec_only == 1 &&
+ seg_32bit == 0 &&
+ limit_in_pages == 0 &&
+ seg_not_present == 1 &&
+ useable == 0 )) {
+ entry_1 = 0;
+ entry_2 = 0;
+ goto install;
+ }
+ }
+
+ entry_1 = ((ldt_info.base_addr & 0x0000ffff) << 16) |
+ (ldt_info.limit & 0x0ffff);
+ entry_2 = (ldt_info.base_addr & 0xff000000) |
+ ((ldt_info.base_addr & 0x00ff0000) >> 16) |
+ (ldt_info.limit & 0xf0000) |
+ ((read_exec_only ^ 1) << 9) |
+ (contents << 10) |
+ ((seg_not_present ^ 1) << 15) |
+ (seg_32bit << 22) |
+ (limit_in_pages << 23) |
+ 0x7000;
+ if (!oldmode)
+ entry_2 |= (useable << 20);
+
+ /* Install the new entry ... */
+install:
+ lp = (uint32_t *)(ldt_table + (ldt_info.entry_number << 3));
+ lp[0] = tswap32(entry_1);
+ lp[1] = tswap32(entry_2);
+ return 0;
+}
+
+/* specific and weird i386 syscalls */
+int gemu_modify_ldt(CPUX86State *env, int func, void *ptr, unsigned long bytecount)
+{
+ int ret = -ENOSYS;
+
+ switch (func) {
+ case 0:
+ ret = read_ldt(ptr, bytecount);
+ break;
+ case 1:
+ ret = write_ldt(env, ptr, bytecount, 1);
+ break;
+ case 0x11:
+ ret = write_ldt(env, ptr, bytecount, 0);
+ break;
+ }
+ return ret;
+}
+#endif
+
void syscall_init(void)
{
#define STRUCT(name, list...) thunk_register_struct(STRUCT_ ## name, #name, struct_ ## name ## _def);
@@ -616,7 +735,7 @@ void syscall_init(void)
#undef STRUCT_SPECIAL
}
-long do_syscall(int num, long arg1, long arg2, long arg3,
+long do_syscall(void *cpu_env, int num, long arg1, long arg2, long arg3,
long arg4, long arg5, long arg6)
{
long ret;
@@ -1095,8 +1214,11 @@ long do_syscall(int num, long arg1, long arg2, long arg3,
/* no need to transcode because we use the linux syscall */
ret = get_errno(sys_uname((struct new_utsname *)arg1));
break;
+#ifdef TARGET_I386
case TARGET_NR_modify_ldt:
- goto unimplemented;
+ ret = get_errno(gemu_modify_ldt(cpu_env, arg1, (void *)arg2, arg3));
+ break;
+#endif
case TARGET_NR_adjtimex:
goto unimplemented;
case TARGET_NR_mprotect:
diff --git a/linux-user/syscall_types.h b/linux-user/syscall_types.h
index 63852d3..5401144 100644
--- a/linux-user/syscall_types.h
+++ b/linux-user/syscall_types.h
@@ -61,4 +61,3 @@ STRUCT(cdrom_read_audio,
STRUCT(hd_geometry,
TYPE_CHAR, TYPE_CHAR, TYPE_SHORT, TYPE_ULONG)
-