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author | Aurelien Jarno <aurelien@aurel32.net> | 2010-03-29 02:12:51 +0200 |
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committer | Aurelien Jarno <aurelien@aurel32.net> | 2010-04-01 21:51:59 +0200 |
commit | 45d679d64350c44df93d918ddacd6ae0c6da9dbb (patch) | |
tree | a2918d748b8c125d6ce4d41506bf3fdcf0a4c092 /exec.c | |
parent | 60e99246d6b4d1de32aec3281483cdd85b415570 (diff) | |
download | qemu-45d679d64350c44df93d918ddacd6ae0c6da9dbb.zip qemu-45d679d64350c44df93d918ddacd6ae0c6da9dbb.tar.gz qemu-45d679d64350c44df93d918ddacd6ae0c6da9dbb.tar.bz2 |
linux-user: fix page_unprotect when host page size > target page size
When the host page size is bigger that the target one, unprotecting a
page should:
- mark all the target pages corresponding to the host page as writable
- invalidate all tb corresponding to the host page (and not the target
page)
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Diffstat (limited to 'exec.c')
-rw-r--r-- | exec.c | 45 |
1 files changed, 22 insertions, 23 deletions
@@ -2498,8 +2498,8 @@ int page_check_range(target_ulong start, target_ulong len, int flags) page. Return TRUE if the fault was successfully handled. */ int page_unprotect(target_ulong address, unsigned long pc, void *puc) { - unsigned int page_index, prot, pindex; - PageDesc *p, *p1; + unsigned int prot; + PageDesc *p; target_ulong host_start, host_end, addr; /* Technically this isn't safe inside a signal handler. However we @@ -2507,37 +2507,36 @@ int page_unprotect(target_ulong address, unsigned long pc, void *puc) 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) { + p = page_find(address >> TARGET_PAGE_BITS); + if (!p) { mmap_unlock(); return 0; } - host_end = host_start + qemu_host_page_size; - p = p1; - prot = 0; - for(addr = host_start;addr < host_end; addr += TARGET_PAGE_SIZE) { - prot |= p->flags; - p++; - } + /* if the page was really writable, then we change its protection back to writable */ - if (prot & PAGE_WRITE_ORG) { - pindex = (address - host_start) >> TARGET_PAGE_BITS; - if (!(p1[pindex].flags & PAGE_WRITE)) { - mprotect((void *)g2h(host_start), qemu_host_page_size, - (prot & PAGE_BITS) | PAGE_WRITE); - p1[pindex].flags |= PAGE_WRITE; + if ((p->flags & PAGE_WRITE_ORG) && !(p->flags & PAGE_WRITE)) { + host_start = address & qemu_host_page_mask; + host_end = host_start + qemu_host_page_size; + + prot = 0; + for (addr = host_start ; addr < host_end ; addr += TARGET_PAGE_SIZE) { + p = page_find(addr >> TARGET_PAGE_BITS); + p->flags |= PAGE_WRITE; + prot |= p->flags; + /* and since the content will be modified, we must invalidate the corresponding translated code. */ - tb_invalidate_phys_page(address, pc, puc); + tb_invalidate_phys_page(addr, pc, puc); #ifdef DEBUG_TB_CHECK - tb_invalidate_check(address); + tb_invalidate_check(addr); #endif - mmap_unlock(); - return 1; } + mprotect((void *)g2h(host_start), qemu_host_page_size, + prot & PAGE_BITS); + + mmap_unlock(); + return 1; } mmap_unlock(); return 0; |