From: Stacey Son <s...@freebsd.org>
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 <s...@freebsd.org>
Signed-off-by: Karim Taha <kariem.taha...@gmail.com>
---
bsd-user/bsd-mem.h | 45 +++++++++++++++++++++++++++++++++++
bsd-user/freebsd/os-syscall.c | 7 ++++++
2 files changed, 52 insertions(+)
diff --git a/bsd-user/bsd-mem.h b/bsd-user/bsd-mem.h
index 1dabbe36e6..563f82996b 100644
--- a/bsd-user/bsd-mem.h
+++ b/bsd-user/bsd-mem.h
@@ -211,4 +211,49 @@ 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 8d1cf3b35c..8dd29fddde 100644
--- a/bsd-user/freebsd/os-syscall.c
+++ b/bsd-user/freebsd/os-syscall.c
@@ -543,6 +543,13 @@ static abi_long freebsd_syscall(void *cpu_env, int num,
abi_long arg1,
break;
#endif
+ /*
+ * Misc
+ */
+ case TARGET_FREEBSD_NR_break:
+ ret = do_obreak(arg1);
+ break;
+
/*
* sys{ctl, arch, call}
*/
--
2.42.0
