diff options
| -rw-r--r-- | linux-user/arm/target_cpu.h | 4 | ||||
| -rw-r--r-- | linux-user/main.c | 38 | ||||
| -rw-r--r-- | target/mips/mips-defs.h | 6 | ||||
| -rw-r--r-- | target/nios2/cpu.h | 6 |
4 files changed, 39 insertions, 15 deletions
diff --git a/linux-user/arm/target_cpu.h b/linux-user/arm/target_cpu.h index d888219150..c3eb4b243d 100644 --- a/linux-user/arm/target_cpu.h +++ b/linux-user/arm/target_cpu.h @@ -19,6 +19,10 @@ #ifndef ARM_TARGET_CPU_H #define ARM_TARGET_CPU_H +/* We need to be able to map the commpage. + See validate_guest_space in linux-user/elfload.c. */ +#define MAX_RESERVED_VA 0xffff0000ul + static inline void cpu_clone_regs(CPUARMState *env, target_ulong newsp) { if (newsp) { diff --git a/linux-user/main.c b/linux-user/main.c index 829f974662..fd54d344bb 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -60,23 +60,38 @@ do { \ } \ } while (0) -#if (TARGET_LONG_BITS == 32) && (HOST_LONG_BITS == 64) /* * When running 32-on-64 we should make sure we can fit all of the possible * guest address space into a contiguous chunk of virtual host memory. * * This way we will never overlap with our own libraries or binaries or stack * or anything else that QEMU maps. + * + * Many cpus reserve the high bit (or more than one for some 64-bit cpus) + * of the address for the kernel. Some cpus rely on this and user space + * uses the high bit(s) for pointer tagging and the like. For them, we + * must preserve the expected address space. */ -# if defined(TARGET_MIPS) || defined(TARGET_NIOS2) -/* - * MIPS only supports 31 bits of virtual address space for user space. - * Nios2 also only supports 31 bits. - */ -unsigned long reserved_va = 0x77000000; +#ifndef MAX_RESERVED_VA +# if HOST_LONG_BITS > TARGET_VIRT_ADDR_SPACE_BITS +# if TARGET_VIRT_ADDR_SPACE_BITS == 32 && \ + (TARGET_LONG_BITS == 32 || defined(TARGET_ABI32)) +/* There are a number of places where we assign reserved_va to a variable + of type abi_ulong and expect it to fit. Avoid the last page. */ +# define MAX_RESERVED_VA (0xfffffffful & TARGET_PAGE_MASK) +# else +# define MAX_RESERVED_VA (1ul << TARGET_VIRT_ADDR_SPACE_BITS) +# endif # else -unsigned long reserved_va = 0xf7000000; +# define MAX_RESERVED_VA 0 # endif +#endif + +/* That said, reserving *too* much vm space via mmap can run into problems + with rlimits, oom due to page table creation, etc. We will still try it, + if directed by the command-line option, but not by default. */ +#if HOST_LONG_BITS == 64 && TARGET_VIRT_ADDR_SPACE_BITS <= 32 +unsigned long reserved_va = MAX_RESERVED_VA; #else unsigned long reserved_va; #endif @@ -3978,11 +3993,8 @@ static void handle_arg_reserved_va(const char *arg) unsigned long unshifted = reserved_va; p++; reserved_va <<= shift; - if (((reserved_va >> shift) != unshifted) -#if HOST_LONG_BITS > TARGET_VIRT_ADDR_SPACE_BITS - || (reserved_va > (1ul << TARGET_VIRT_ADDR_SPACE_BITS)) -#endif - ) { + if (reserved_va >> shift != unshifted + || (MAX_RESERVED_VA && reserved_va > MAX_RESERVED_VA)) { fprintf(stderr, "Reserved virtual address too big\n"); exit(EXIT_FAILURE); } diff --git a/target/mips/mips-defs.h b/target/mips/mips-defs.h index 047554ee45..d239069975 100644 --- a/target/mips/mips-defs.h +++ b/target/mips/mips-defs.h @@ -15,7 +15,11 @@ #else #define TARGET_LONG_BITS 32 #define TARGET_PHYS_ADDR_SPACE_BITS 40 -#define TARGET_VIRT_ADDR_SPACE_BITS 32 +# ifdef CONFIG_USER_ONLY +# define TARGET_VIRT_ADDR_SPACE_BITS 31 +# else +# define TARGET_VIRT_ADDR_SPACE_BITS 32 +#endif #endif /* Masks used to mark instructions to indicate which ISA level they diff --git a/target/nios2/cpu.h b/target/nios2/cpu.h index 50d803a217..9119eee587 100644 --- a/target/nios2/cpu.h +++ b/target/nios2/cpu.h @@ -226,7 +226,11 @@ qemu_irq *nios2_cpu_pic_init(Nios2CPU *cpu); void nios2_check_interrupts(CPUNios2State *env); #define TARGET_PHYS_ADDR_SPACE_BITS 32 -#define TARGET_VIRT_ADDR_SPACE_BITS 32 +#ifdef CONFIG_USER_ONLY +# define TARGET_VIRT_ADDR_SPACE_BITS 31 +#else +# define TARGET_VIRT_ADDR_SPACE_BITS 32 +#endif #define cpu_init(cpu_model) cpu_generic_init(TYPE_NIOS2_CPU, cpu_model) |