From f51f315a676ec913a55ac27be4ef857f9f7ddc5c Mon Sep 17 00:00:00 2001 From: "Emilio G. Cota" Date: Sat, 15 Jul 2017 02:38:57 -0400 Subject: [PATCH] translate-all: use qemu_protect_rwx/none helpers The helpers require the address and size to be page-aligned, so do that before calling them. Reviewed-by: Richard Henderson Signed-off-by: Emilio G. Cota Signed-off-by: Richard Henderson --- accel/tcg/translate-all.c | 61 +++++++++------------------------------ 1 file changed, 13 insertions(+), 48 deletions(-) diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index 78c150af3e..9061c0508c 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -602,63 +602,24 @@ static inline void *split_cross_256mb(void *buf1, size_t size1) static uint8_t static_code_gen_buffer[DEFAULT_CODE_GEN_BUFFER_SIZE] __attribute__((aligned(CODE_GEN_ALIGN))); -# ifdef _WIN32 -static inline void do_protect(void *addr, long size, int prot) -{ - DWORD old_protect; - VirtualProtect(addr, size, prot, &old_protect); -} - -static inline void map_exec(void *addr, long size) -{ - do_protect(addr, size, PAGE_EXECUTE_READWRITE); -} - -static inline void map_none(void *addr, long size) -{ - do_protect(addr, size, PAGE_NOACCESS); -} -# else -static inline void do_protect(void *addr, long size, int prot) -{ - uintptr_t start, end; - - start = (uintptr_t)addr; - start &= qemu_real_host_page_mask; - - end = (uintptr_t)addr + size; - end = ROUND_UP(end, qemu_real_host_page_size); - - mprotect((void *)start, end - start, prot); -} - -static inline void map_exec(void *addr, long size) -{ - do_protect(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC); -} - -static inline void map_none(void *addr, long size) -{ - do_protect(addr, size, PROT_NONE); -} -# endif /* WIN32 */ - static inline void *alloc_code_gen_buffer(void) { void *buf = static_code_gen_buffer; + void *end = static_code_gen_buffer + sizeof(static_code_gen_buffer); size_t full_size, size; - /* The size of the buffer, rounded down to end on a page boundary. */ - full_size = (((uintptr_t)buf + sizeof(static_code_gen_buffer)) - & qemu_real_host_page_mask) - (uintptr_t)buf; + /* page-align the beginning and end of the buffer */ + buf = QEMU_ALIGN_PTR_UP(buf, qemu_real_host_page_size); + end = QEMU_ALIGN_PTR_DOWN(end, qemu_real_host_page_size); /* Reserve a guard page. */ + full_size = end - buf; size = full_size - qemu_real_host_page_size; /* Honor a command-line option limiting the size of the buffer. */ if (size > tcg_ctx->code_gen_buffer_size) { - size = (((uintptr_t)buf + tcg_ctx->code_gen_buffer_size) - & qemu_real_host_page_mask) - (uintptr_t)buf; + size = QEMU_ALIGN_DOWN(tcg_ctx->code_gen_buffer_size, + qemu_real_host_page_size); } tcg_ctx->code_gen_buffer_size = size; @@ -669,8 +630,12 @@ static inline void *alloc_code_gen_buffer(void) } #endif - map_exec(buf, size); - map_none(buf + size, qemu_real_host_page_size); + if (qemu_mprotect_rwx(buf, size)) { + abort(); + } + if (qemu_mprotect_none(buf + size, qemu_real_host_page_size)) { + abort(); + } qemu_madvise(buf, size, QEMU_MADV_HUGEPAGE); return buf; -- 2.39.2