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qemu/linux-user/qemu.h
Helge Deller 1f356e8c01 linux-user: Adjust initial brk when interpreter is close to executable 
While we attempt to load a ET_DYN executable far away from
TASK_UNMAPPED_BASE, we are not completely in control of the
address space layout.  If the interpreter lands close to
the executable, leaving insufficient heap space, move brk.

Tested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>
[rth: Re-order after ELF_ET_DYN_BASE patch so that we do not
 "temporarily break" tsan, and also to minimize the changes required.
 Remove image_info.reserve_brk as unused.]
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-08-08 13:27:17 -07:00

354 lines
13 KiB
C
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#ifndef QEMU_H
#define QEMU_H
#include "cpu.h"
#include "exec/cpu_ldst.h"
#undef DEBUG_REMAP
#include "exec/user/abitypes.h"
#include "syscall_defs.h"
#include "target_syscall.h"
/*
* This is the size of the host kernel's sigset_t, needed where we make
* direct system calls that take a sigset_t pointer and a size.
*/
#define SIGSET_T_SIZE (_NSIG / 8)
/*
* This struct is used to hold certain information about the image.
* Basically, it replicates in user space what would be certain
* task_struct fields in the kernel
*/
struct image_info {
abi_ulong load_bias;
abi_ulong load_addr;
abi_ulong start_code;
abi_ulong end_code;
abi_ulong start_data;
abi_ulong end_data;
abi_ulong brk;
abi_ulong start_mmap;
abi_ulong start_stack;
abi_ulong stack_limit;
abi_ulong entry;
abi_ulong code_offset;
abi_ulong data_offset;
abi_ulong saved_auxv;
abi_ulong auxv_len;
abi_ulong argc;
abi_ulong argv;
abi_ulong envc;
abi_ulong envp;
abi_ulong file_string;
uint32_t elf_flags;
int personality;
abi_ulong alignment;
bool exec_stack;
/* Generic semihosting knows about these pointers. */
abi_ulong arg_strings; /* strings for argv */
abi_ulong env_strings; /* strings for envp; ends arg_strings */
/* The fields below are used in FDPIC mode. */
abi_ulong loadmap_addr;
uint16_t nsegs;
void *loadsegs;
abi_ulong pt_dynamic_addr;
abi_ulong interpreter_loadmap_addr;
abi_ulong interpreter_pt_dynamic_addr;
struct image_info *other_info;
/* For target-specific processing of NT_GNU_PROPERTY_TYPE_0. */
uint32_t note_flags;
#ifdef TARGET_MIPS
int fp_abi;
int interp_fp_abi;
#endif
};
#ifdef TARGET_I386
/* Information about the current linux thread */
struct vm86_saved_state {
uint32_t eax; /* return code */
uint32_t ebx;
uint32_t ecx;
uint32_t edx;
uint32_t esi;
uint32_t edi;
uint32_t ebp;
uint32_t esp;
uint32_t eflags;
uint32_t eip;
uint16_t cs, ss, ds, es, fs, gs;
};
#endif
#if defined(TARGET_ARM) && defined(TARGET_ABI32)
/* FPU emulator */
#include "nwfpe/fpa11.h"
#endif
struct emulated_sigtable {
int pending; /* true if signal is pending */
target_siginfo_t info;
};
typedef struct TaskState {
pid_t ts_tid; /* tid (or pid) of this task */
#ifdef TARGET_ARM
# ifdef TARGET_ABI32
/* FPA state */
FPA11 fpa;
# endif
#endif
#if defined(TARGET_ARM) || defined(TARGET_RISCV)
int swi_errno;
#endif
#if defined(TARGET_I386) && !defined(TARGET_X86_64)
abi_ulong target_v86;
struct vm86_saved_state vm86_saved_regs;
struct target_vm86plus_struct vm86plus;
uint32_t v86flags;
uint32_t v86mask;
#endif
abi_ulong child_tidptr;
#ifdef TARGET_M68K
abi_ulong tp_value;
#endif
#if defined(TARGET_ARM) || defined(TARGET_M68K) || defined(TARGET_RISCV)
/* Extra fields for semihosted binaries. */
abi_ulong heap_base;
abi_ulong heap_limit;
#endif
abi_ulong stack_base;
int used; /* non zero if used */
struct image_info *info;
struct linux_binprm *bprm;
struct emulated_sigtable sync_signal;
struct emulated_sigtable sigtab[TARGET_NSIG];
/*
* This thread's signal mask, as requested by the guest program.
* The actual signal mask of this thread may differ:
* + we don't let SIGSEGV and SIGBUS be blocked while running guest code
* + sometimes we block all signals to avoid races
*/
sigset_t signal_mask;
/*
* The signal mask imposed by a guest sigsuspend syscall, if we are
* currently in the middle of such a syscall
*/
sigset_t sigsuspend_mask;
/* Nonzero if we're leaving a sigsuspend and sigsuspend_mask is valid. */
int in_sigsuspend;
/*
* Nonzero if process_pending_signals() needs to do something (either
* handle a pending signal or unblock signals).
* This flag is written from a signal handler so should be accessed via
* the qatomic_read() and qatomic_set() functions. (It is not accessed
* from multiple threads.)
*/
int signal_pending;
/* This thread's sigaltstack, if it has one */
struct target_sigaltstack sigaltstack_used;
/* Start time of task after system boot in clock ticks */
uint64_t start_boottime;
} TaskState;
abi_long do_brk(abi_ulong new_brk);
int do_guest_openat(CPUArchState *cpu_env, int dirfd, const char *pathname,
int flags, mode_t mode, bool safe);
ssize_t do_guest_readlink(const char *pathname, char *buf, size_t bufsiz);
/* user access */
#define VERIFY_NONE 0
#define VERIFY_READ PAGE_READ
#define VERIFY_WRITE (PAGE_READ | PAGE_WRITE)
static inline bool access_ok_untagged(int type, abi_ulong addr, abi_ulong size)
{
if (size == 0
? !guest_addr_valid_untagged(addr)
: !guest_range_valid_untagged(addr, size)) {
return false;
}
return page_check_range((target_ulong)addr, size, type);
}
static inline bool access_ok(CPUState *cpu, int type,
abi_ulong addr, abi_ulong size)
{
return access_ok_untagged(type, cpu_untagged_addr(cpu, addr), size);
}
/* NOTE __get_user and __put_user use host pointers and don't check access.
These are usually used to access struct data members once the struct has
been locked - usually with lock_user_struct. */
/*
* Tricky points:
* - Use __builtin_choose_expr to avoid type promotion from ?:,
* - Invalid sizes result in a compile time error stemming from
* the fact that abort has no parameters.
* - It's easier to use the endian-specific unaligned load/store
* functions than host-endian unaligned load/store plus tswapN.
* - The pragmas are necessary only to silence a clang false-positive
* warning: see https://bugs.llvm.org/show_bug.cgi?id=39113 .
* - gcc has bugs in its _Pragma() support in some versions, eg
* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 -- so we only
* include the warning-suppression pragmas for clang
*/
#if defined(__clang__) && __has_warning("-Waddress-of-packed-member")
#define PRAGMA_DISABLE_PACKED_WARNING \
_Pragma("GCC diagnostic push"); \
_Pragma("GCC diagnostic ignored \"-Waddress-of-packed-member\"")
#define PRAGMA_REENABLE_PACKED_WARNING \
_Pragma("GCC diagnostic pop")
#else
#define PRAGMA_DISABLE_PACKED_WARNING
#define PRAGMA_REENABLE_PACKED_WARNING
#endif
#define __put_user_e(x, hptr, e) \
do { \
PRAGMA_DISABLE_PACKED_WARNING; \
(__builtin_choose_expr(sizeof(*(hptr)) == 1, stb_p, \
__builtin_choose_expr(sizeof(*(hptr)) == 2, stw_##e##_p, \
__builtin_choose_expr(sizeof(*(hptr)) == 4, stl_##e##_p, \
__builtin_choose_expr(sizeof(*(hptr)) == 8, stq_##e##_p, abort)))) \
((hptr), (x)), (void)0); \
PRAGMA_REENABLE_PACKED_WARNING; \
} while (0)
#define __get_user_e(x, hptr, e) \
do { \
PRAGMA_DISABLE_PACKED_WARNING; \
((x) = (typeof(*hptr))( \
__builtin_choose_expr(sizeof(*(hptr)) == 1, ldub_p, \
__builtin_choose_expr(sizeof(*(hptr)) == 2, lduw_##e##_p, \
__builtin_choose_expr(sizeof(*(hptr)) == 4, ldl_##e##_p, \
__builtin_choose_expr(sizeof(*(hptr)) == 8, ldq_##e##_p, abort)))) \
(hptr)), (void)0); \
PRAGMA_REENABLE_PACKED_WARNING; \
} while (0)
#if TARGET_BIG_ENDIAN
# define __put_user(x, hptr) __put_user_e(x, hptr, be)
# define __get_user(x, hptr) __get_user_e(x, hptr, be)
#else
# define __put_user(x, hptr) __put_user_e(x, hptr, le)
# define __get_user(x, hptr) __get_user_e(x, hptr, le)
#endif
/* put_user()/get_user() take a guest address and check access */
/* These are usually used to access an atomic data type, such as an int,
* that has been passed by address. These internally perform locking
* and unlocking on the data type.
*/
#define put_user(x, gaddr, target_type) \
({ \
abi_ulong __gaddr = (gaddr); \
target_type *__hptr; \
abi_long __ret = 0; \
if ((__hptr = lock_user(VERIFY_WRITE, __gaddr, sizeof(target_type), 0))) { \
__put_user((x), __hptr); \
unlock_user(__hptr, __gaddr, sizeof(target_type)); \
} else \
__ret = -TARGET_EFAULT; \
__ret; \
})
#define get_user(x, gaddr, target_type) \
({ \
abi_ulong __gaddr = (gaddr); \
target_type *__hptr; \
abi_long __ret = 0; \
if ((__hptr = lock_user(VERIFY_READ, __gaddr, sizeof(target_type), 1))) { \
__get_user((x), __hptr); \
unlock_user(__hptr, __gaddr, 0); \
} else { \
/* avoid warning */ \
(x) = 0; \
__ret = -TARGET_EFAULT; \
} \
__ret; \
})
#define put_user_ual(x, gaddr) put_user((x), (gaddr), abi_ulong)
#define put_user_sal(x, gaddr) put_user((x), (gaddr), abi_long)
#define put_user_u64(x, gaddr) put_user((x), (gaddr), uint64_t)
#define put_user_s64(x, gaddr) put_user((x), (gaddr), int64_t)
#define put_user_u32(x, gaddr) put_user((x), (gaddr), uint32_t)
#define put_user_s32(x, gaddr) put_user((x), (gaddr), int32_t)
#define put_user_u16(x, gaddr) put_user((x), (gaddr), uint16_t)
#define put_user_s16(x, gaddr) put_user((x), (gaddr), int16_t)
#define put_user_u8(x, gaddr) put_user((x), (gaddr), uint8_t)
#define put_user_s8(x, gaddr) put_user((x), (gaddr), int8_t)
#define get_user_ual(x, gaddr) get_user((x), (gaddr), abi_ulong)
#define get_user_sal(x, gaddr) get_user((x), (gaddr), abi_long)
#define get_user_u64(x, gaddr) get_user((x), (gaddr), uint64_t)
#define get_user_s64(x, gaddr) get_user((x), (gaddr), int64_t)
#define get_user_u32(x, gaddr) get_user((x), (gaddr), uint32_t)
#define get_user_s32(x, gaddr) get_user((x), (gaddr), int32_t)
#define get_user_u16(x, gaddr) get_user((x), (gaddr), uint16_t)
#define get_user_s16(x, gaddr) get_user((x), (gaddr), int16_t)
#define get_user_u8(x, gaddr) get_user((x), (gaddr), uint8_t)
#define get_user_s8(x, gaddr) get_user((x), (gaddr), int8_t)
/* copy_from_user() and copy_to_user() are usually used to copy data
* buffers between the target and host. These internally perform
* locking/unlocking of the memory.
*/
int copy_from_user(void *hptr, abi_ulong gaddr, ssize_t len);
int copy_to_user(abi_ulong gaddr, void *hptr, ssize_t len);
/* Functions for accessing guest memory. The tget and tput functions
read/write single values, byteswapping as necessary. The lock_user function
gets a pointer to a contiguous area of guest memory, but does not perform
any byteswapping. lock_user may return either a pointer to the guest
memory, or a temporary buffer. */
/* Lock an area of guest memory into the host. If copy is true then the
host area will have the same contents as the guest. */
void *lock_user(int type, abi_ulong guest_addr, ssize_t len, bool copy);
/* Unlock an area of guest memory. The first LEN bytes must be
flushed back to guest memory. host_ptr = NULL is explicitly
allowed and does nothing. */
#ifndef DEBUG_REMAP
static inline void unlock_user(void *host_ptr, abi_ulong guest_addr,
ssize_t len)
{
/* no-op */
}
#else
void unlock_user(void *host_ptr, abi_ulong guest_addr, ssize_t len);
#endif
/* Return the length of a string in target memory or -TARGET_EFAULT if
access error. */
ssize_t target_strlen(abi_ulong gaddr);
/* Like lock_user but for null terminated strings. */
void *lock_user_string(abi_ulong guest_addr);
/* Helper macros for locking/unlocking a target struct. */
#define lock_user_struct(type, host_ptr, guest_addr, copy) \
(host_ptr = lock_user(type, guest_addr, sizeof(*host_ptr), copy))
#define unlock_user_struct(host_ptr, guest_addr, copy) \
unlock_user(host_ptr, guest_addr, (copy) ? sizeof(*host_ptr) : 0)
#endif /* QEMU_H */
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