diff options
| author | Richard Henderson <richard.henderson@linaro.org> | 2021-02-12 10:48:44 -0800 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2021-02-16 11:04:53 +0000 |
| commit | ee1bf83de79143e5893f19e1aa657d1c37ba0c70 (patch) | |
| tree | 163104bfebabbbf4f8f76fb092c30fea02ea6966 /linux-user/syscall.c | |
| parent | 3e8f1628e864201692aa28996f8f64f9761555af (diff) | |
linux-user: Explicitly untag memory management syscalls
We define target_mmap et al as untagged, so that they can be
used from the binary loaders. Explicitly call cpu_untagged_addr
for munmap, mprotect, mremap syscall entry points.
Add a few comments for the syscalls that are exempted by the
kernel's tagged-address-abi.rst.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210212184902.1251044-14-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'linux-user/syscall.c')
| -rw-r--r-- | linux-user/syscall.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/linux-user/syscall.c b/linux-user/syscall.c index e7fd99f1ac..d5badd753e 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -894,6 +894,8 @@ abi_long do_brk(abi_ulong new_brk) abi_long mapped_addr; abi_ulong new_alloc_size; + /* brk pointers are always untagged */ + DEBUGF_BRK("do_brk(" TARGET_ABI_FMT_lx ") -> ", new_brk); if (!new_brk) { @@ -4599,6 +4601,8 @@ static inline abi_ulong do_shmat(CPUArchState *cpu_env, int i,ret; abi_ulong shmlba; + /* shmat pointers are always untagged */ + /* find out the length of the shared memory segment */ ret = get_errno(shmctl(shmid, IPC_STAT, &shm_info)); if (is_error(ret)) { @@ -4666,6 +4670,8 @@ static inline abi_long do_shmdt(abi_ulong shmaddr) int i; abi_long rv; + /* shmdt pointers are always untagged */ + mmap_lock(); for (i = 0; i < N_SHM_REGIONS; ++i) { @@ -9703,6 +9709,7 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1, v5, v6)); } #else + /* mmap pointers are always untagged */ ret = get_errno(target_mmap(arg1, arg2, arg3, target_to_host_bitmask(arg4, mmap_flags_tbl), arg5, @@ -9721,8 +9728,10 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1, return get_errno(ret); #endif case TARGET_NR_munmap: + arg1 = cpu_untagged_addr(cpu, arg1); return get_errno(target_munmap(arg1, arg2)); case TARGET_NR_mprotect: + arg1 = cpu_untagged_addr(cpu, arg1); { TaskState *ts = cpu->opaque; /* Special hack to detect libc making the stack executable. */ @@ -9737,6 +9746,8 @@ static abi_long do_syscall1(void *cpu_env, int num, abi_long arg1, return get_errno(target_mprotect(arg1, arg2, arg3)); #ifdef TARGET_NR_mremap case TARGET_NR_mremap: + arg1 = cpu_untagged_addr(cpu, arg1); + /* mremap new_addr (arg5) is always untagged */ return get_errno(target_mremap(arg1, arg2, arg3, arg4, arg5)); #endif /* ??? msync/mlock/munlock are broken for softmmu. */ |