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syscall: Add readlink to x86 with special case /proc/self/exe

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This patch implements the correct behavior.
This commit is contained in:
David Hashe 2015-07-20 09:15:18 -05:00
parent 4710eba588
commit d0f6aad3c6
2 changed files with 29 additions and 8 deletions
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6
src/arch/x86/linux/process.cc
View file

@ -485,7 +485,7 @@ static SyscallDesc syscallDescs64[] = {
/* 264 */ SyscallDesc("renameat", unimplementedFunc),
/* 265 */ SyscallDesc("linkat", unimplementedFunc),
/* 266 */ SyscallDesc("symlinkat", unimplementedFunc),
/* 267 */ SyscallDesc("readlinkat", unimplementedFunc),
/* 267 */ SyscallDesc("readlinkat", readlinkFunc),
/* 268 */ SyscallDesc("fchmodat", unimplementedFunc),
/* 269 */ SyscallDesc("faccessat", unimplementedFunc),
/* 270 */ SyscallDesc("pselect6", unimplementedFunc),
@ -626,7 +626,7 @@ static SyscallDesc syscallDescs32[] = {
/* 82 */ SyscallDesc("select", unimplementedFunc),
/* 83 */ SyscallDesc("symlink", unimplementedFunc),
/* 84 */ SyscallDesc("oldlstat", unimplementedFunc),
/* 85 */ SyscallDesc("readlink", unimplementedFunc),
/* 85 */ SyscallDesc("readlink", readlinkFunc),
/* 86 */ SyscallDesc("uselib", unimplementedFunc),
/* 87 */ SyscallDesc("swapon", unimplementedFunc),
/* 88 */ SyscallDesc("reboot", unimplementedFunc),
@ -846,7 +846,7 @@ static SyscallDesc syscallDescs32[] = {
/* 302 */ SyscallDesc("renameat", unimplementedFunc),
/* 303 */ SyscallDesc("linkat", unimplementedFunc),
/* 304 */ SyscallDesc("symlinkat", unimplementedFunc),
/* 305 */ SyscallDesc("readlinkat", unimplementedFunc),
/* 305 */ SyscallDesc("readlinkat", readlinkFunc),
/* 306 */ SyscallDesc("fchmodat", unimplementedFunc),
/* 307 */ SyscallDesc("faccessat", unimplementedFunc),
/* 308 */ SyscallDesc("pselect6", unimplementedFunc),

31
src/sim/syscall_emul.cc
View file

@ -365,12 +365,10 @@ getcwdFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc)
}
strncpy((char *)buf.bufferPtr(), cwd.c_str(), size);
result = cwd.length();
}
else {
} else {
if (getcwd((char *)buf.bufferPtr(), size) != NULL) {
result = strlen((char *)buf.bufferPtr());
}
else {
} else {
result = -1;
}
}
@ -405,7 +403,30 @@ readlinkFunc(SyscallDesc *desc, int num, LiveProcess *p, ThreadContext *tc,
BufferArg buf(bufPtr, bufsiz);
int result = readlink(path.c_str(), (char *)buf.bufferPtr(), bufsiz);
int result = -1;
if (path != "/proc/self/exe") {
result = readlink(path.c_str(), (char *)buf.bufferPtr(), bufsiz);
} else {
// readlink() will return the path of the binary given
// with the -c option, however it is possible that this
// will still result in incorrect behavior if one binary
// runs another, e.g., -c time -o "my_binary" where
// my_binary calls readlink(). this is a very unlikely case,
// so we issue a warning.
warn_once("readlink may yield unexpected results if multiple "
"binaries are used\n");
if (strlen(p->progName()) > bufsiz) {
// readlink will truncate the contents of the
// path to ensure it is no more than bufsiz
strncpy((char*)buf.bufferPtr(), p->progName(), bufsiz);
result = bufsiz;
} else {
// return the program's working path rather
// than the one for the gem5 binary itself.
strcpy((char*)buf.bufferPtr(), p->progName());
result = strlen((char*)buf.bufferPtr());
}
}
buf.copyOut(tc->getMemProxy());