diff options
| author | Stacey Son <sson@FreeBSD.org> | 2023-09-25 21:27:04 +0300 |
|---|---|---|
| committer | Warner Losh <imp@bsdimp.com> | 2023-10-03 17:14:07 -0600 |
| commit | a99d74034754b1d8735d814cf17db6bf0eb4bfd1 (patch) | |
| tree | 6ac2b10c1e1fc29f7eb60d831c6d6246bd7a3d7d /bsd-user | |
| parent | 83b045ad4e0106836963185ed696991883104359 (diff) | |
bsd-user: Implement do_obreak function
Match linux-user, by manually applying the following commits, in order:
d28b3c90cfad1a7e211ae2bce36ecb9071086129 linux-user: Make sure initial brk(0) is page-aligned
15ad98536ad9410fb32ddf1ff09389b677643faa linux-user: Fix qemu brk() to not zero bytes on current page
dfe49864afb06e7e452a4366051697bc4fcfc1a5 linux-user: Prohibit brk() to to shrink below initial heap address
eac78a4b0b7da4de2c0a297f4d528ca9cc6256a3 linux-user: Fix signed math overflow in brk() syscall
c6cc059eca18d9f6e4e26bb8b6d1135ddb35d81a linux-user: Do not call get_errno() in do_brk()
e69e032d1a8ee8d754ca119009a3c2c997f8bb30 linux-user: Use MAP_FIXED_NOREPLACE for do_brk()
cb9d5d1fda0bc2312fc0c779b4ea1d7bf826f31f linux-user: Do nothing if too small brk is specified
2aea137a425a87b930a33590177b04368fd7cc12 linux-user: Do not align brk with host page size
Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Karim Taha <kariem.taha2.7@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230925182709.4834-19-kariem.taha2.7@gmail.com>
Diffstat (limited to 'bsd-user')
| -rw-r--r-- | bsd-user/bsd-mem.h | 45 | ||||
| -rw-r--r-- | bsd-user/freebsd/os-syscall.c | 7 |
2 files changed, 52 insertions, 0 deletions
diff --git a/bsd-user/bsd-mem.h b/bsd-user/bsd-mem.h index 0c8d96d9a4..b296c5c6f0 100644 --- a/bsd-user/bsd-mem.h +++ b/bsd-user/bsd-mem.h @@ -212,4 +212,49 @@ static inline abi_long do_bsd_mincore(abi_ulong target_addr, abi_ulong len, return ret; } +/* do_brk() must return target values and target errnos. */ +static inline abi_long do_obreak(abi_ulong brk_val) +{ + abi_long mapped_addr; + abi_ulong new_brk; + abi_ulong old_brk; + + /* brk pointers are always untagged */ + + /* do not allow to shrink below initial brk value */ + if (brk_val < initial_target_brk) { + return target_brk; + } + + new_brk = TARGET_PAGE_ALIGN(brk_val); + old_brk = TARGET_PAGE_ALIGN(target_brk); + + /* new and old target_brk might be on the same page */ + if (new_brk == old_brk) { + target_brk = brk_val; + return target_brk; + } + + /* Release heap if necesary */ + if (new_brk < old_brk) { + target_munmap(new_brk, old_brk - new_brk); + + target_brk = brk_val; + return target_brk; + } + + mapped_addr = target_mmap(old_brk, new_brk - old_brk, + PROT_READ | PROT_WRITE, + MAP_FIXED | MAP_EXCL | MAP_ANON | MAP_PRIVATE, + -1, 0); + + if (mapped_addr == old_brk) { + target_brk = brk_val; + return target_brk; + } + + /* For everything else, return the previous break. */ + return target_brk; +} + #endif /* BSD_USER_BSD_MEM_H */ diff --git a/bsd-user/freebsd/os-syscall.c b/bsd-user/freebsd/os-syscall.c index f054241cd6..92793ab1fb 100644 --- a/bsd-user/freebsd/os-syscall.c +++ b/bsd-user/freebsd/os-syscall.c @@ -856,6 +856,13 @@ static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1, #endif /* + * Misc + */ + case TARGET_FREEBSD_NR_break: + ret = do_obreak(arg1); + break; + + /* * sys{ctl, arch, call} */ case TARGET_FREEBSD_NR___sysctl: /* sysctl(3) */ |