Multithreaded locking for mmap().
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4654 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
pbrook
parent
30813cea9b
commit
c8a706fe62
20
exec.c
20
exec.c
@ -234,6 +234,7 @@ static void page_init(void)
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FILE *f;
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int n;
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mmap_lock();
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last_brk = (unsigned long)sbrk(0);
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f = fopen("/proc/self/maps", "r");
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if (f) {
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@ -251,6 +252,7 @@ static void page_init(void)
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} while (!feof(f));
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fclose(f);
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}
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mmap_unlock();
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}
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#endif
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}
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@ -326,6 +328,8 @@ static inline PhysPageDesc *phys_page_find(target_phys_addr_t index)
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static void tlb_protect_code(ram_addr_t ram_addr);
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static void tlb_unprotect_code_phys(CPUState *env, ram_addr_t ram_addr,
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target_ulong vaddr);
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#define mmap_lock() do { } while(0)
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#define mmap_unlock() do { } while(0)
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#endif
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#define DEFAULT_CODE_GEN_BUFFER_SIZE (32 * 1024 * 1024)
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@ -1049,6 +1053,9 @@ void tb_link_phys(TranslationBlock *tb,
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unsigned int h;
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TranslationBlock **ptb;
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/* Grab the mmap lock to stop another thread invalidating this TB
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before we are done. */
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mmap_lock();
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/* add in the physical hash table */
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h = tb_phys_hash_func(phys_pc);
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ptb = &tb_phys_hash[h];
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@ -1075,6 +1082,7 @@ void tb_link_phys(TranslationBlock *tb,
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#ifdef DEBUG_TB_CHECK
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tb_page_check();
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#endif
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mmap_unlock();
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}
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/* find the TB 'tb' such that tb[0].tc_ptr <= tc_ptr <
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@ -2002,6 +2010,7 @@ void page_set_flags(target_ulong start, target_ulong end, int flags)
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PageDesc *p;
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target_ulong addr;
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/* mmap_lock should already be held. */
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start = start & TARGET_PAGE_MASK;
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end = TARGET_PAGE_ALIGN(end);
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if (flags & PAGE_WRITE)
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@ -2065,11 +2074,18 @@ int page_unprotect(target_ulong address, unsigned long pc, void *puc)
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PageDesc *p, *p1;
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target_ulong host_start, host_end, addr;
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/* Technically this isn't safe inside a signal handler. However we
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know this only ever happens in a synchronous SEGV handler, so in
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practice it seems to be ok. */
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mmap_lock();
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host_start = address & qemu_host_page_mask;
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page_index = host_start >> TARGET_PAGE_BITS;
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p1 = page_find(page_index);
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if (!p1)
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if (!p1) {
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mmap_unlock();
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return 0;
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}
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host_end = host_start + qemu_host_page_size;
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p = p1;
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prot = 0;
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@ -2091,9 +2107,11 @@ int page_unprotect(target_ulong address, unsigned long pc, void *puc)
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#ifdef DEBUG_TB_CHECK
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tb_invalidate_check(address);
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#endif
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mmap_unlock();
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return 1;
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}
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}
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mmap_unlock();
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return 0;
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}
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@ -29,6 +29,34 @@
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//#define DEBUG_MMAP
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#if defined(USE_NPTL)
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pthread_mutex_t mmap_mutex;
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static int __thread mmap_lock_count;
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void mmap_lock(void)
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{
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if (mmap_lock_count++ == 0) {
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pthread_mutex_lock(&mmap_mutex);
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}
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}
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void mmap_unlock(void)
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{
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if (--mmap_lock_count == 0) {
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pthread_mutex_unlock(&mmap_mutex);
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}
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}
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#else
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/* We aren't threadsafe to start with, so no need to worry about locking. */
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void mmap_lock(void)
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{
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}
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void mmap_unlock(void)
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{
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}
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#endif
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/* NOTE: all the constants are the HOST ones, but addresses are target. */
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int target_mprotect(abi_ulong start, abi_ulong len, int prot)
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{
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@ -53,6 +81,7 @@ int target_mprotect(abi_ulong start, abi_ulong len, int prot)
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if (len == 0)
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return 0;
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mmap_lock();
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host_start = start & qemu_host_page_mask;
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host_end = HOST_PAGE_ALIGN(end);
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if (start > host_start) {
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@ -69,7 +98,7 @@ int target_mprotect(abi_ulong start, abi_ulong len, int prot)
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}
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ret = mprotect(g2h(host_start), qemu_host_page_size, prot1 & PAGE_BITS);
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if (ret != 0)
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return ret;
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goto error;
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host_start += qemu_host_page_size;
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}
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if (end < host_end) {
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@ -80,7 +109,7 @@ int target_mprotect(abi_ulong start, abi_ulong len, int prot)
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ret = mprotect(g2h(host_end - qemu_host_page_size), qemu_host_page_size,
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prot1 & PAGE_BITS);
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if (ret != 0)
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return ret;
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goto error;
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host_end -= qemu_host_page_size;
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}
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@ -88,10 +117,14 @@ int target_mprotect(abi_ulong start, abi_ulong len, int prot)
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if (host_start < host_end) {
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ret = mprotect(g2h(host_start), host_end - host_start, prot);
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if (ret != 0)
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return ret;
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goto error;
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}
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page_set_flags(start, start + len, prot | PAGE_VALID);
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mmap_unlock();
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return 0;
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error:
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mmap_unlock();
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return ret;
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}
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/* map an incomplete host page */
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@ -214,6 +247,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
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abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len;
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unsigned long host_start;
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mmap_lock();
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#ifdef DEBUG_MMAP
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{
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printf("mmap: start=0x" TARGET_FMT_lx
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@ -243,12 +277,12 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
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if (offset & ~TARGET_PAGE_MASK) {
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errno = EINVAL;
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return -1;
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goto fail;
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}
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len = TARGET_PAGE_ALIGN(len);
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if (len == 0)
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return start;
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goto the_end;
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real_start = start & qemu_host_page_mask;
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if (!(flags & MAP_FIXED)) {
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@ -260,7 +294,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
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mmap_start = mmap_find_vma(real_start, host_len);
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if (mmap_start == (abi_ulong)-1) {
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errno = ENOMEM;
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return -1;
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goto fail;
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}
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/* Note: we prefer to control the mapping address. It is
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especially important if qemu_host_page_size >
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@ -268,7 +302,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
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p = mmap(g2h(mmap_start),
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host_len, prot, flags | MAP_FIXED, fd, host_offset);
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if (p == MAP_FAILED)
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return -1;
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goto fail;
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/* update start so that it points to the file position at 'offset' */
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host_start = (unsigned long)p;
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if (!(flags & MAP_ANONYMOUS))
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@ -280,7 +314,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
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if (start & ~TARGET_PAGE_MASK) {
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errno = EINVAL;
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return -1;
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goto fail;
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}
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end = start + len;
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real_end = HOST_PAGE_ALIGN(end);
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@ -289,7 +323,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
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flg = page_get_flags(addr);
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if (flg & PAGE_RESERVED) {
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errno = ENXIO;
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return -1;
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goto fail;
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}
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}
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@ -302,18 +336,20 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
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if ((flags & MAP_TYPE) == MAP_SHARED &&
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(prot & PROT_WRITE)) {
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errno = EINVAL;
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return -1;
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goto fail;
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}
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retaddr = target_mmap(start, len, prot | PROT_WRITE,
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MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS,
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-1, 0);
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if (retaddr == -1)
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return -1;
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goto fail;
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pread(fd, g2h(start), len, offset);
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if (!(prot & PROT_WRITE)) {
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ret = target_mprotect(start, len, prot);
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if (ret != 0)
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return ret;
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if (ret != 0) {
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start = ret;
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goto the_end;
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}
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}
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goto the_end;
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}
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@ -325,13 +361,13 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
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ret = mmap_frag(real_start, start, end,
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prot, flags, fd, offset);
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if (ret == -1)
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return ret;
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goto fail;
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goto the_end1;
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}
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ret = mmap_frag(real_start, start, real_start + qemu_host_page_size,
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prot, flags, fd, offset);
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if (ret == -1)
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return ret;
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goto fail;
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real_start += qemu_host_page_size;
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}
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/* handle the end of the mapping */
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@ -341,7 +377,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
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prot, flags, fd,
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offset + real_end - qemu_host_page_size - start);
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if (ret == -1)
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return -1;
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goto fail;
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real_end -= qemu_host_page_size;
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}
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@ -356,7 +392,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
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p = mmap(g2h(real_start), real_end - real_start,
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prot, flags, fd, offset1);
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if (p == MAP_FAILED)
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return -1;
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goto fail;
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}
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}
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the_end1:
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@ -367,7 +403,11 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
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page_dump(stdout);
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printf("\n");
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#endif
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mmap_unlock();
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return start;
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fail:
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mmap_unlock();
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return -1;
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}
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int target_munmap(abi_ulong start, abi_ulong len)
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@ -383,6 +423,7 @@ int target_munmap(abi_ulong start, abi_ulong len)
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len = TARGET_PAGE_ALIGN(len);
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if (len == 0)
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return -EINVAL;
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mmap_lock();
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end = start + len;
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real_start = start & qemu_host_page_mask;
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real_end = HOST_PAGE_ALIGN(end);
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@ -411,15 +452,16 @@ int target_munmap(abi_ulong start, abi_ulong len)
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real_end -= qemu_host_page_size;
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}
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ret = 0;
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/* unmap what we can */
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if (real_start < real_end) {
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ret = munmap(g2h(real_start), real_end - real_start);
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if (ret != 0)
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return ret;
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}
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page_set_flags(start, start + len, 0);
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return 0;
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if (ret == 0)
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page_set_flags(start, start + len, 0);
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mmap_unlock();
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return ret;
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}
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/* XXX: currently, we only handle MAP_ANONYMOUS and not MAP_FIXED
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@ -431,14 +473,18 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
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int prot;
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unsigned long host_addr;
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mmap_lock();
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/* XXX: use 5 args syscall */
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host_addr = (long)mremap(g2h(old_addr), old_size, new_size, flags);
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if (host_addr == -1)
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return -1;
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new_addr = h2g(host_addr);
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prot = page_get_flags(old_addr);
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page_set_flags(old_addr, old_addr + old_size, 0);
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page_set_flags(new_addr, new_addr + new_size, prot | PAGE_VALID);
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if (host_addr == -1) {
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new_addr = -1;
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} else {
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new_addr = h2g(host_addr);
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prot = page_get_flags(old_addr);
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page_set_flags(old_addr, old_addr + old_size, 0);
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page_set_flags(new_addr, new_addr + new_size, prot | PAGE_VALID);
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}
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mmap_unlock();
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return new_addr;
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}
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@ -233,6 +233,8 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
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abi_ulong new_addr);
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int target_msync(abi_ulong start, abi_ulong len, int flags);
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extern unsigned long last_brk;
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void mmap_lock(void);
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void mmap_unlock(void);
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/* user access */
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@ -423,4 +425,8 @@ static inline void *lock_user_string(abi_ulong guest_addr)
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#define unlock_user_struct(host_ptr, guest_addr, copy) \
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unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
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#if defined(USE_NPTL)
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#include <pthread.h>
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#endif
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#endif /* QEMU_H */
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