diff options
| -rw-r--r-- | exec.c | 20 | ||||
| -rw-r--r-- | linux-user/mmap.c | 100 | ||||
| -rw-r--r-- | linux-user/qemu.h | 6 |
3 files changed, 98 insertions, 28 deletions
@@ -234,6 +234,7 @@ static void page_init(void) FILE *f; int n; + mmap_lock(); last_brk = (unsigned long)sbrk(0); f = fopen("/proc/self/maps", "r"); if (f) { @@ -251,6 +252,7 @@ static void page_init(void) } while (!feof(f)); fclose(f); } + mmap_unlock(); } #endif } @@ -326,6 +328,8 @@ static inline PhysPageDesc *phys_page_find(target_phys_addr_t index) static void tlb_protect_code(ram_addr_t ram_addr); static void tlb_unprotect_code_phys(CPUState *env, ram_addr_t ram_addr, target_ulong vaddr); +#define mmap_lock() do { } while(0) +#define mmap_unlock() do { } while(0) #endif #define DEFAULT_CODE_GEN_BUFFER_SIZE (32 * 1024 * 1024) @@ -1049,6 +1053,9 @@ void tb_link_phys(TranslationBlock *tb, unsigned int h; TranslationBlock **ptb; + /* Grab the mmap lock to stop another thread invalidating this TB + before we are done. */ + mmap_lock(); /* add in the physical hash table */ h = tb_phys_hash_func(phys_pc); ptb = &tb_phys_hash[h]; @@ -1075,6 +1082,7 @@ void tb_link_phys(TranslationBlock *tb, #ifdef DEBUG_TB_CHECK tb_page_check(); #endif + mmap_unlock(); } /* find the TB 'tb' such that tb[0].tc_ptr <= tc_ptr < @@ -2002,6 +2010,7 @@ void page_set_flags(target_ulong start, target_ulong end, int flags) PageDesc *p; target_ulong addr; + /* mmap_lock should already be held. */ start = start & TARGET_PAGE_MASK; end = TARGET_PAGE_ALIGN(end); if (flags & PAGE_WRITE) @@ -2065,11 +2074,18 @@ int page_unprotect(target_ulong address, unsigned long pc, void *puc) PageDesc *p, *p1; target_ulong host_start, host_end, addr; + /* Technically this isn't safe inside a signal handler. However we + know this only ever happens in a synchronous SEGV handler, so in + practice it seems to be ok. */ + mmap_lock(); + host_start = address & qemu_host_page_mask; page_index = host_start >> TARGET_PAGE_BITS; p1 = page_find(page_index); - if (!p1) + if (!p1) { + mmap_unlock(); return 0; + } host_end = host_start + qemu_host_page_size; p = p1; prot = 0; @@ -2091,9 +2107,11 @@ int page_unprotect(target_ulong address, unsigned long pc, void *puc) #ifdef DEBUG_TB_CHECK tb_invalidate_check(address); #endif + mmap_unlock(); return 1; } } + mmap_unlock(); return 0; } diff --git a/linux-user/mmap.c b/linux-user/mmap.c index 794b1d05eb..c0821386d9 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -29,6 +29,34 @@ //#define DEBUG_MMAP +#if defined(USE_NPTL) +pthread_mutex_t mmap_mutex; +static int __thread mmap_lock_count; + +void mmap_lock(void) +{ + if (mmap_lock_count++ == 0) { + pthread_mutex_lock(&mmap_mutex); + } +} + +void mmap_unlock(void) +{ + if (--mmap_lock_count == 0) { + pthread_mutex_unlock(&mmap_mutex); + } +} +#else +/* We aren't threadsafe to start with, so no need to worry about locking. */ +void mmap_lock(void) +{ +} + +void mmap_unlock(void) +{ +} +#endif + /* NOTE: all the constants are the HOST ones, but addresses are target. */ int target_mprotect(abi_ulong start, abi_ulong len, int prot) { @@ -53,6 +81,7 @@ int target_mprotect(abi_ulong start, abi_ulong len, int prot) if (len == 0) return 0; + mmap_lock(); host_start = start & qemu_host_page_mask; host_end = HOST_PAGE_ALIGN(end); if (start > host_start) { @@ -69,7 +98,7 @@ int target_mprotect(abi_ulong start, abi_ulong len, int prot) } ret = mprotect(g2h(host_start), qemu_host_page_size, prot1 & PAGE_BITS); if (ret != 0) - return ret; + goto error; host_start += qemu_host_page_size; } if (end < host_end) { @@ -80,7 +109,7 @@ int target_mprotect(abi_ulong start, abi_ulong len, int prot) ret = mprotect(g2h(host_end - qemu_host_page_size), qemu_host_page_size, prot1 & PAGE_BITS); if (ret != 0) - return ret; + goto error; host_end -= qemu_host_page_size; } @@ -88,10 +117,14 @@ int target_mprotect(abi_ulong start, abi_ulong len, int prot) if (host_start < host_end) { ret = mprotect(g2h(host_start), host_end - host_start, prot); if (ret != 0) - return ret; + goto error; } page_set_flags(start, start + len, prot | PAGE_VALID); + mmap_unlock(); return 0; +error: + mmap_unlock(); + return ret; } /* map an incomplete host page */ @@ -214,6 +247,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len; unsigned long host_start; + mmap_lock(); #ifdef DEBUG_MMAP { printf("mmap: start=0x" TARGET_FMT_lx @@ -243,12 +277,12 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, if (offset & ~TARGET_PAGE_MASK) { errno = EINVAL; - return -1; + goto fail; } len = TARGET_PAGE_ALIGN(len); if (len == 0) - return start; + goto the_end; real_start = start & qemu_host_page_mask; if (!(flags & MAP_FIXED)) { @@ -260,7 +294,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, mmap_start = mmap_find_vma(real_start, host_len); if (mmap_start == (abi_ulong)-1) { errno = ENOMEM; - return -1; + goto fail; } /* Note: we prefer to control the mapping address. It is especially important if qemu_host_page_size > @@ -268,7 +302,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, p = mmap(g2h(mmap_start), host_len, prot, flags | MAP_FIXED, fd, host_offset); if (p == MAP_FAILED) - return -1; + goto fail; /* update start so that it points to the file position at 'offset' */ host_start = (unsigned long)p; if (!(flags & MAP_ANONYMOUS)) @@ -280,7 +314,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, if (start & ~TARGET_PAGE_MASK) { errno = EINVAL; - return -1; + goto fail; } end = start + len; real_end = HOST_PAGE_ALIGN(end); @@ -289,7 +323,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, flg = page_get_flags(addr); if (flg & PAGE_RESERVED) { errno = ENXIO; - return -1; + goto fail; } } @@ -302,18 +336,20 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, if ((flags & MAP_TYPE) == MAP_SHARED && (prot & PROT_WRITE)) { errno = EINVAL; - return -1; + goto fail; } retaddr = target_mmap(start, len, prot | PROT_WRITE, MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (retaddr == -1) - return -1; + goto fail; pread(fd, g2h(start), len, offset); if (!(prot & PROT_WRITE)) { ret = target_mprotect(start, len, prot); - if (ret != 0) - return ret; + if (ret != 0) { + start = ret; + goto the_end; + } } goto the_end; } @@ -325,13 +361,13 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, ret = mmap_frag(real_start, start, end, prot, flags, fd, offset); if (ret == -1) - return ret; + goto fail; goto the_end1; } ret = mmap_frag(real_start, start, real_start + qemu_host_page_size, prot, flags, fd, offset); if (ret == -1) - return ret; + goto fail; real_start += qemu_host_page_size; } /* handle the end of the mapping */ @@ -341,7 +377,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, prot, flags, fd, offset + real_end - qemu_host_page_size - start); if (ret == -1) - return -1; + goto fail; real_end -= qemu_host_page_size; } @@ -356,7 +392,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, p = mmap(g2h(real_start), real_end - real_start, prot, flags, fd, offset1); if (p == MAP_FAILED) - return -1; + goto fail; } } the_end1: @@ -367,7 +403,11 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, page_dump(stdout); printf("\n"); #endif + mmap_unlock(); return start; +fail: + mmap_unlock(); + return -1; } int target_munmap(abi_ulong start, abi_ulong len) @@ -383,6 +423,7 @@ int target_munmap(abi_ulong start, abi_ulong len) len = TARGET_PAGE_ALIGN(len); if (len == 0) return -EINVAL; + mmap_lock(); end = start + len; real_start = start & qemu_host_page_mask; real_end = HOST_PAGE_ALIGN(end); @@ -411,15 +452,16 @@ int target_munmap(abi_ulong start, abi_ulong len) real_end -= qemu_host_page_size; } + ret = 0; /* unmap what we can */ if (real_start < real_end) { ret = munmap(g2h(real_start), real_end - real_start); - if (ret != 0) - return ret; } - page_set_flags(start, start + len, 0); - return 0; + if (ret == 0) + page_set_flags(start, start + len, 0); + mmap_unlock(); + return ret; } /* XXX: currently, we only handle MAP_ANONYMOUS and not MAP_FIXED @@ -431,14 +473,18 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size, int prot; unsigned long host_addr; + mmap_lock(); /* XXX: use 5 args syscall */ host_addr = (long)mremap(g2h(old_addr), old_size, new_size, flags); - if (host_addr == -1) - return -1; - new_addr = h2g(host_addr); - prot = page_get_flags(old_addr); - page_set_flags(old_addr, old_addr + old_size, 0); - page_set_flags(new_addr, new_addr + new_size, prot | PAGE_VALID); + if (host_addr == -1) { + new_addr = -1; + } else { + new_addr = h2g(host_addr); + prot = page_get_flags(old_addr); + page_set_flags(old_addr, old_addr + old_size, 0); + page_set_flags(new_addr, new_addr + new_size, prot | PAGE_VALID); + } + mmap_unlock(); return new_addr; } diff --git a/linux-user/qemu.h b/linux-user/qemu.h index 093b8ff8a3..7a38bfe074 100644 --- a/linux-user/qemu.h +++ b/linux-user/qemu.h @@ -233,6 +233,8 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size, abi_ulong new_addr); int target_msync(abi_ulong start, abi_ulong len, int flags); extern unsigned long last_brk; +void mmap_lock(void); +void mmap_unlock(void); /* user access */ @@ -423,4 +425,8 @@ static inline void *lock_user_string(abi_ulong guest_addr) #define unlock_user_struct(host_ptr, guest_addr, copy) \ unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0) +#if defined(USE_NPTL) +#include <pthread.h> +#endif + #endif /* QEMU_H */ |