derek/gem5
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

sim-se: Rewrite some syscalls to use a syscallImpl function

Browse Source 
The following at suffixed syscalls are implemented on top of their
CWD version

* readlinkat -> readlink
* unlinkat -> unlink
* renameat -> rename
* faccessat -> access

With this patch we are decoupling interface from implementation, moving
the latter into a separate syscallImpl function which will by called by
both syscall flavours

This is a required step towards properly implementing AT based syscalls

JIRA: https://gem5.atlassian.net/browse/GEM5-1098

Change-Id: I022e9876a2a0b9ddf2d70d10cd4e6851ba7ff094
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/51047
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Reviewed-by: Richard Cooper <richard.cooper@arm.com>
This commit is contained in:
Giacomo Travaglini
2021-09-27 16:14:24 +01:00
parent 9854685277
commit 8f1f50f410
2 changed files with 69 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

41
src/sim/syscall_emul.cc
View File

@@ -403,11 +403,18 @@ readlinkFunc(SyscallDesc *desc, ThreadContext *tc,
VPtr<> pathname, VPtr<> buf_ptr, size_t bufsiz)
{
std::string path;
auto p = tc->getProcessPtr();
if (!SETranslatingPortProxy(tc).tryReadString(path, pathname))
return -EFAULT;
return readlinkImpl(desc, tc, path, buf_ptr, bufsiz);
}
SyscallReturn
readlinkImpl(SyscallDesc *desc, ThreadContext *tc,
std::string path, VPtr<> buf_ptr, size_t bufsiz)
{
auto p = tc->getProcessPtr();
// Adjust path for cwd and redirection
path = p->checkPathRedirect(path);
@@ -460,11 +467,16 @@ SyscallReturn
unlinkFunc(SyscallDesc *desc, ThreadContext *tc, VPtr<> pathname)
{
std::string path;
auto p = tc->getProcessPtr();
if (!SETranslatingPortProxy(tc).tryReadString(path, pathname))
return -EFAULT;
return unlinkImpl(desc, tc, path);
}
SyscallReturn
unlinkImpl(SyscallDesc *desc, ThreadContext *tc, std::string path)
{
auto p = tc->getProcessPtr();
path = p->checkPathRedirect(path);
int result = unlink(path.c_str());
@@ -531,8 +543,6 @@ SyscallReturn
renameFunc(SyscallDesc *desc, ThreadContext *tc, VPtr<> oldpath,
VPtr<> newpath)
{
auto p = tc->getProcessPtr();
SETranslatingPortProxy proxy(tc);
std::string old_name;
if (!proxy.tryReadString(old_name, oldpath))
@@ -542,6 +552,15 @@ renameFunc(SyscallDesc *desc, ThreadContext *tc, VPtr<> oldpath,
if (!proxy.tryReadString(new_name, newpath))
return -EFAULT;
return renameImpl(desc, tc, old_name, new_name);
}
SyscallReturn
renameImpl(SyscallDesc *desc, ThreadContext *tc,
std::string old_name, std::string new_name)
{
auto p = tc->getProcessPtr();
// Adjust path for cwd and redirection
old_name = p->checkPathRedirect(old_name);
new_name = p->checkPathRedirect(new_name);
@@ -550,6 +569,7 @@ renameFunc(SyscallDesc *desc, ThreadContext *tc, VPtr<> oldpath,
return (result == -1) ? -errno : result;
}
SyscallReturn
truncateFunc(SyscallDesc *desc, ThreadContext *tc, VPtr<> pathname,
off_t length)
@@ -1011,10 +1031,17 @@ accessFunc(SyscallDesc *desc, ThreadContext *tc,
VPtr<> pathname, mode_t mode)
{
std::string path;
auto p = tc->getProcessPtr();
if (!SETranslatingPortProxy(tc).tryReadString(path, pathname))
return -EFAULT;
return accessImpl(desc, tc, path, mode);
}
SyscallReturn
accessImpl(SyscallDesc *desc, ThreadContext *tc,
std::string path, mode_t mode)
{
auto p = tc->getProcessPtr();
// Adjust path for cwd and redirection
path = p->checkPathRedirect(path);

39
src/sim/syscall_emul.hh
View File

@@ -191,10 +191,14 @@ SyscallReturn getcwdFunc(SyscallDesc *desc, ThreadContext *tc,
/// Target readlink() handler.
SyscallReturn readlinkFunc(SyscallDesc *desc, ThreadContext *tc,
VPtr<> pathname, VPtr<> buf, size_t bufsiz);
SyscallReturn readlinkImpl(SyscallDesc *desc, ThreadContext *tc,
std::string path, VPtr<> buf, size_t bufsiz);
/// Target unlink() handler.
SyscallReturn unlinkFunc(SyscallDesc *desc, ThreadContext *tc,
VPtr<> pathname);
SyscallReturn unlinkImpl(SyscallDesc *desc, ThreadContext *tc,
std::string path);
/// Target link() handler
SyscallReturn linkFunc(SyscallDesc *desc, ThreadContext *tc,
@@ -221,6 +225,8 @@ SyscallReturn rmdirFunc(SyscallDesc *desc, ThreadContext *tc, VPtr<> pathname);
/// Target rename() handler.
SyscallReturn renameFunc(SyscallDesc *desc, ThreadContext *tc,
VPtr<> oldpath, VPtr<> newpath);
SyscallReturn renameImpl(SyscallDesc *desc, ThreadContext *tc,
std::string oldpath, std::string newpath);
/// Target truncate() handler.
@@ -353,6 +359,8 @@ SyscallReturn getegidFunc(SyscallDesc *desc, ThreadContext *tc);
/// Target access() handler
SyscallReturn accessFunc(SyscallDesc *desc, ThreadContext *tc,
VPtr<> pathname, mode_t mode);
SyscallReturn accessImpl(SyscallDesc *desc, ThreadContext *tc,
std::string path, mode_t mode);
// Target getsockopt() handler.
SyscallReturn getsockoptFunc(SyscallDesc *desc, ThreadContext *tc,
@@ -916,10 +924,14 @@ template <class OS>
SyscallReturn
unlinkatFunc(SyscallDesc *desc, ThreadContext *tc, int dirfd, VPtr<> pathname)
{
std::string path;
if (!SETranslatingPortProxy(tc).tryReadString(path, pathname))
return -EFAULT;
if (dirfd != OS::TGT_AT_FDCWD)
warn("unlinkat: first argument not AT_FDCWD; unlikely to work");
return unlinkFunc(desc, tc, pathname);
return unlinkImpl(desc, tc, path);
}
/// Target facessat() handler
@@ -928,9 +940,14 @@ SyscallReturn
faccessatFunc(SyscallDesc *desc, ThreadContext *tc,
int dirfd, VPtr<> pathname, int mode)
{
std::string path;
if (!SETranslatingPortProxy(tc).tryReadString(path, pathname))
return -EFAULT;
if (dirfd != OS::TGT_AT_FDCWD)
warn("faccessat: first argument not AT_FDCWD; unlikely to work");
return accessFunc(desc, tc, pathname, mode);
return accessImpl(desc, tc, path, mode);
}
/// Target readlinkat() handler
@@ -939,9 +956,14 @@ SyscallReturn
readlinkatFunc(SyscallDesc *desc, ThreadContext *tc,
int dirfd, VPtr<> pathname, VPtr<> buf, size_t bufsiz)
{
std::string path;
if (!SETranslatingPortProxy(tc).tryReadString(path, pathname))
return -EFAULT;
if (dirfd != OS::TGT_AT_FDCWD)
warn("openat: first argument not AT_FDCWD; unlikely to work");
return readlinkFunc(desc, tc, pathname, buf, bufsiz);
return readlinkImpl(desc, tc, path, buf, bufsiz);
}
/// Target renameat() handler.
@@ -950,13 +972,22 @@ SyscallReturn
renameatFunc(SyscallDesc *desc, ThreadContext *tc,
int olddirfd, VPtr<> oldpath, int newdirfd, VPtr<> newpath)
{
SETranslatingPortProxy proxy(tc);
std::string old_name;
if (!proxy.tryReadString(old_name, oldpath))
return -EFAULT;
std::string new_name;
if (!proxy.tryReadString(new_name, newpath))
return -EFAULT;
if (olddirfd != OS::TGT_AT_FDCWD)
warn("renameat: first argument not AT_FDCWD; unlikely to work");
if (newdirfd != OS::TGT_AT_FDCWD)
warn("renameat: third argument not AT_FDCWD; unlikely to work");
return renameFunc(desc, tc, oldpath, newpath);
return renameImpl(desc, tc, old_name, new_name);
}
/// Target sysinfo() handler.