diff options
| author | Richard Henderson <richard.henderson@linaro.org> | 2023-07-07 21:40:39 +0100 |
|---|---|---|
| committer | Richard Henderson <richard.henderson@linaro.org> | 2023-07-15 08:02:32 +0100 |
| commit | 037986053b063866b029733d9508635d31b3f987 (patch) | |
| tree | 3e6c3abb9e95e2897f578fdc0391c0ab5ad4e92b | |
| parent | 9c255cb53e44d5db57b3388fd6dfab96d4883790 (diff) | |
linux-user: Implement MAP_FIXED_NOREPLACE
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230707204054.8792-12-richard.henderson@linaro.org>
| -rw-r--r-- | linux-user/mmap.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/linux-user/mmap.c b/linux-user/mmap.c index 639921dba0..9dc34fc29d 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -509,7 +509,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot, * If the user is asking for the kernel to find a location, do that * before we truncate the length for mapping files below. */ - if (!(flags & MAP_FIXED)) { + if (!(flags & (MAP_FIXED | MAP_FIXED_NOREPLACE))) { host_len = len + offset - host_offset; host_len = HOST_PAGE_ALIGN(host_len); start = mmap_find_vma(real_start, host_len, TARGET_PAGE_SIZE); @@ -551,7 +551,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot, } } - if (!(flags & MAP_FIXED)) { + if (!(flags & (MAP_FIXED | MAP_FIXED_NOREPLACE))) { unsigned long host_start; void *p; @@ -600,6 +600,13 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot, goto fail; } + /* Validate that the chosen range is empty. */ + if ((flags & MAP_FIXED_NOREPLACE) + && !page_check_range_empty(start, end - 1)) { + errno = EEXIST; + goto fail; + } + /* * worst case: we cannot map the file because the offset is not * aligned, so we read it @@ -615,7 +622,8 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot, goto fail; } retaddr = target_mmap(start, len, target_prot | PROT_WRITE, - MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, + (flags & (MAP_FIXED | MAP_FIXED_NOREPLACE)) + | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (retaddr == -1) { goto fail; |