Brandon Potter has uploaded this change for review. (
https://gem5-review.googlesource.com/c/public/gem5/+/12310
Change subject: syscall_emul: adding pipe2 syscall
......................................................................
syscall_emul: adding pipe2 syscall
pipe2 builds on top of the pipe syscall implementation by
adding some extra flags for the files (to avoid have to
make separate calls to fcntl).
Change-Id: I88cf6f1387b9d14e60b33a32db412da9ed93a3e6
---
M src/arch/x86/linux/process.cc
M src/sim/syscall_emul.cc
M src/sim/syscall_emul.hh
3 files changed, 62 insertions(+), 5 deletions(-)
diff --git a/src/arch/x86/linux/process.cc b/src/arch/x86/linux/process.cc
index ceaa4ba..2928fa7 100644
--- a/src/arch/x86/linux/process.cc
+++ b/src/arch/x86/linux/process.cc
@@ -520,7 +520,7 @@
/* 290 */ SyscallDesc("eventfd2", eventfdFunc<X86Linux64>),
/* 291 */ SyscallDesc("epoll_create1", unimplementedFunc),
/* 292 */ SyscallDesc("dup3", unimplementedFunc),
- /* 293 */ SyscallDesc("pipe2", unimplementedFunc),
+ /* 293 */ SyscallDesc("pipe2", pipe2Func),
/* 294 */ SyscallDesc("inotify_init1", unimplementedFunc),
/* 295 */ SyscallDesc("preadv", unimplementedFunc),
/* 296 */ SyscallDesc("pwritev", unimplementedFunc),
diff --git a/src/sim/syscall_emul.cc b/src/sim/syscall_emul.cc
index b9fe8e4..6d687ff 100644
--- a/src/sim/syscall_emul.cc
+++ b/src/sim/syscall_emul.cc
@@ -829,13 +829,18 @@
}
SyscallReturn
-pipeImpl(SyscallDesc *desc, int callnum, ThreadContext *tc, bool
pseudoPipe)
+pipeImpl(SyscallDesc *desc, int callnum, ThreadContext *tc, bool
pseudo_pipe,
+ bool is_pipe2)
{
Addr tgt_addr = 0;
+ int flags = 0;
auto p = tc->getProcessPtr();
- if (!pseudoPipe) {
+ if (!pseudo_pipe) {
int index = 0;
tgt_addr = p->getSyscallArg(tc, index);
+ if (is_pipe2) {
+ flags = p->getSyscallArg(tc, index);
+ }
}
int sim_fds[2], tgt_fds[2];
@@ -847,10 +852,12 @@
auto rend = PipeFDEntry::EndType::read;
auto rpfd = std::make_shared<PipeFDEntry>(sim_fds[0], O_WRONLY, rend);
tgt_fds[0] = p->fds->allocFD(rpfd);
+ int sim_fd_rpfd = rpfd->getSimFD();
auto wend = PipeFDEntry::EndType::write;
auto wpfd = std::make_shared<PipeFDEntry>(sim_fds[1], O_RDONLY, wend);
tgt_fds[1] = p->fds->allocFD(wpfd);
+ int sim_fd_wpfd = wpfd->getSimFD();
/**
* Now patch the read object to record the target file descriptor
chosen
@@ -862,7 +869,7 @@
* Alpha Linux convention for pipe() is that fd[0] is returned as
* the return value of the function, and fd[1] is returned in r20.
*/
- if (pseudoPipe) {
+ if (pseudo_pipe) {
tc->setIntReg(SyscallPseudoReturnReg, tgt_fds[1]);
return tgt_fds[0];
}
@@ -879,6 +886,45 @@
auto mem_state = p->memState;
auto &virt_mem = mem_state->getVirtMem();
tgt_handle.copyOut(virt_mem);
+
+ // pipe2 has additional behavior if flags != 0
+ if (is_pipe2 && flags) {
+ // pipe2 only uses O_NONBLOCK, O_CLOEXEC, and (O_NONBLOCK |
O_CLOEXEC)
+ // if flags set to anything else, return EINVAL
+ if ((flags != O_CLOEXEC) && (flags != O_NONBLOCK) &&
+ (flags != (O_CLOEXEC | O_NONBLOCK))) {
+ return -EINVAL;
+ }
+
+ /*
+ If O_NONBLOCK is passed in as a flag to pipe2, set O_NONBLOCK
file
+ status flag for two new open file descriptors.
+ */
+ if (flags & O_NONBLOCK) {
+ /*
+ O_NONBLOCK is set when the programmer wants to avoid a
separate
+ call(s) to fcntl in their code, so mirror the fcntl
+ implementation for handling file descriptors -- rely on host
to
+ maintain file status flags.
+ */
+ if (fcntl(sim_fd_rpfd, F_SETFL, O_NONBLOCK)) {
+ return -errno;
+ }
+ if (fcntl(sim_fd_wpfd, F_SETFL, O_NONBLOCK)) {
+ return -errno;
+ }
+ }
+
+ /*
+ If O_CLOEXEC is passed in as a flag to pipe2, set close-on-exec
+ (FD_CLOEXEC) file status flag for two new open file descriptors.
+ */
+ if (flags & O_CLOEXEC) {
+ rpfd->setCOE(true);
+ wpfd->setCOE(true);
+ }
+ }
+
return 0;
}
@@ -895,6 +941,14 @@
}
SyscallReturn
+pipe2Func(SyscallDesc *desc, int callnum, ThreadContext *tc)
+{
+ // call pipeImpl since the only difference between pipe and pipe2 is
+ // the flags values and what they do (at the end of pipeImpl)
+ return pipeImpl(desc, callnum, tc, false, true);
+}
+
+SyscallReturn
setpgidFunc(SyscallDesc *desc, int callnum, ThreadContext *tc)
{
int index = 0;
diff --git a/src/sim/syscall_emul.hh b/src/sim/syscall_emul.hh
index fc1b7ca..619cc04 100644
--- a/src/sim/syscall_emul.hh
+++ b/src/sim/syscall_emul.hh
@@ -267,7 +267,10 @@
/// Internal pipe() handler.
SyscallReturn pipeImpl(SyscallDesc *desc, int num, ThreadContext *tc,
- bool pseudoPipe);
+ bool pseudo_pipe, bool is_pipe2=false);
+
+/// Target pipe() handler.
+SyscallReturn pipe2Func(SyscallDesc *desc, int num, ThreadContext *tc);
/// Target getpid() handler.
SyscallReturn getpidFunc(SyscallDesc *desc, int num, ThreadContext *tc);
--
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Gerrit-Project: public/gem5
Gerrit-Branch: master
Gerrit-Change-Id: I88cf6f1387b9d14e60b33a32db412da9ed93a3e6
Gerrit-Change-Number: 12310
Gerrit-PatchSet: 1
Gerrit-Owner: Brandon Potter <[email protected]>
Gerrit-MessageType: newchange
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