From 43526150fac8e7d36739e948cb3ca2f433e4e607 Mon Sep 17 00:00:00 2001 From: Alexander Graf Date: Mon, 7 May 2012 11:23:02 +0200 Subject: [PATCH] linux-user: Fix stale tbs after mmap If we execute linux-user code that does the following: * A = mmap() * execute code in A * munmap(A) * B = mmap(), but mmap returns the same address as A * execute code in B we end up executing a stale cached tb that contains translated code from A, while we want new code from B. This patch adds a TB flush for mmap'ed regions, before we return them, avoiding the whole issue. Reported-by: Peter Maydell Signed-off-by: Alexander Graf --- exec-all.h | 2 ++ exec.c | 17 +++++++++++++++++ linux-user/mmap.c | 2 ++ 3 files changed, 21 insertions(+), 0 deletions(-) diff --git a/exec-all.h b/exec-all.h index c211242..7fcd76f 100644 --- a/exec-all.h +++ b/exec-all.h @@ -96,6 +96,8 @@ void QEMU_NORETURN cpu_loop_exit(CPUState *env1); int page_unprotect(target_ulong address, unsigned long pc, void *puc); void tb_invalidate_phys_page_range(tb_page_addr_t start, tb_page_addr_t end, int is_cpu_write_access); +void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end, + int is_cpu_write_access); void tlb_flush_page(CPUState *env, target_ulong addr); void tlb_flush(CPUState *env, int flush_global); #if !defined(CONFIG_USER_ONLY) diff --git a/exec.c b/exec.c index e71a82d..532b00c 100644 --- a/exec.c +++ b/exec.c @@ -1016,6 +1016,23 @@ TranslationBlock *tb_gen_code(CPUState *env, return tb; } +/* + * invalidate all TBs which intersect with the target physical pages + * starting in range [start;end[. NOTE: start and end may refer to + * different physical pages. 'is_cpu_write_access' should be true if called + * from a real cpu write access: the virtual CPU will exit the current + * TB if code is modified inside this TB. + */ +void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end, + int is_cpu_write_access) +{ + while (start < end) { + tb_invalidate_phys_page_range(start, end, is_cpu_write_access); + start &= TARGET_PAGE_MASK; + start += TARGET_PAGE_SIZE; + } +} + /* invalidate all TBs which intersect with the target physical page starting in range [start;end[. NOTE: start and end must refer to the same physical page. 'is_cpu_write_access' should be true if called diff --git a/linux-user/mmap.c b/linux-user/mmap.c index 2620f88..3611deb 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -587,6 +587,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, page_dump(stdout); printf("\n"); #endif + tb_invalidate_phys_range(start, start + len, 0); mmap_unlock(); return start; fail: @@ -768,6 +769,7 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size, page_set_flags(old_addr, old_addr + old_size, 0); page_set_flags(new_addr, new_addr + new_size, prot | PAGE_VALID); } + tb_invalidate_phys_range(new_addr, new_addr + new_size, 0); mmap_unlock(); return new_addr; }