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| author | kib <kib@FreeBSD.org> | 2011-04-08 21:26:50 +0000 |
|---|---|---|
| committer | kib <kib@FreeBSD.org> | 2011-04-08 21:26:50 +0000 |
| commit | dae91cc1408e54eaebf0fd410992b3a0d7d26d5a (patch) | |
| tree | c0a6c16dd23cf8037179bc2b4f23fcb95e27da03 /sys/amd64/amd64/exception.S | |
| parent | 096c7a804fc82a151f8b7d1a6811fd08aa223699 (diff) | |
| download | FreeBSD-src-dae91cc1408e54eaebf0fd410992b3a0d7d26d5a.zip FreeBSD-src-dae91cc1408e54eaebf0fd410992b3a0d7d26d5a.tar.gz | |
Disable local interrupts before testing the PCB_FULL_IRET flag.
Thread might be preempted after testing, which causes the flag to be
cleared. If ast was not delivered, we will do sysret with potentially
wrong fs/gs bases.
Reviewed by: jhb, jkim
MFC after: 1 week (together with r220430, r220452)
Diffstat (limited to 'sys/amd64/amd64/exception.S')
| -rw-r--r-- | sys/amd64/amd64/exception.S | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/sys/amd64/amd64/exception.S b/sys/amd64/amd64/exception.S index 65515aa..c537a4f 100644 --- a/sys/amd64/amd64/exception.S +++ b/sys/amd64/amd64/exception.S @@ -383,10 +383,11 @@ IDTVEC(fast_syscall) movq %rsp,%rdi call syscall 1: movq PCPU(CURPCB),%rax + /* Disable interrupts before testing PCB_FULL_IRET. */ + cli testl $PCB_FULL_IRET,PCB_FLAGS(%rax) jnz 3f /* Check for and handle AST's on return to userland. */ - cli movq PCPU(CURTHREAD),%rax testl $TDF_ASTPENDING | TDF_NEEDRESCHED,TD_FLAGS(%rax) je 2f |
