From: Di Chen <dichen@redhat.com>
Date: Thu, 14 Apr 2022 16:08:17 +0000 (+0800)
Subject: Support new memfd_secret linux syscall (447)
X-Git-Tag: VALGRIND_3_20_0~101
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fca4a3d8e59c29bc7d239ff4de72b1260c0c23ee;p=thirdparty%2Fvalgrind.git

Support new memfd_secret linux syscall (447)

memfd_secret is a new syscall in linux 5.14. memfd_secret() is
disabled by default and a command-line option needs to be added to
enable it at boot time.

$ cat /proc/cmdline
[...] secretmem.enable=y

https://bugs.kde.org/451878
https://lwn.net/Articles/865256/
---

diff --git a/coregrind/m_syswrap/priv_syswrap-linux.h b/coregrind/m_syswrap/priv_syswrap-linux.h
index baf362f112..d929caf5ed 100644
--- a/coregrind/m_syswrap/priv_syswrap-linux.h
+++ b/coregrind/m_syswrap/priv_syswrap-linux.h
@@ -323,6 +323,9 @@ DECL_TEMPLATE(linux, sys_io_uring_register);
 // Linux-specific (new in Linux 5.9)
 DECL_TEMPLATE(linux, sys_close_range);
 
+// Linux-specific (new in Linux 5.14)
+DECL_TEMPLATE(linux, sys_memfd_secret);
+
 /* ---------------------------------------------------------------------
    Wrappers for sockets and ipc-ery.  These are split into standalone
    procedures because x86-linux hides them inside multiplexors
diff --git a/coregrind/m_syswrap/syswrap-amd64-linux.c b/coregrind/m_syswrap/syswrap-amd64-linux.c
index 18b25f80ae..430907c49e 100644
--- a/coregrind/m_syswrap/syswrap-amd64-linux.c
+++ b/coregrind/m_syswrap/syswrap-amd64-linux.c
@@ -880,6 +880,8 @@ static SyscallTableEntry syscall_table[] = {
    LINXY(__NR_close_range,       sys_close_range),       // 436
 
    LINX_(__NR_faccessat2,	 sys_faccessat2),        // 439
+
+   LINXY(__NR_memfd_secret,      sys_memfd_secret),      // 447
 };
 
 SyscallTableEntry* ML_(get_linux_syscall_entry) ( UInt sysno )
diff --git a/coregrind/m_syswrap/syswrap-arm64-linux.c b/coregrind/m_syswrap/syswrap-arm64-linux.c
index 2066a38ea9..3ed71e143b 100644
--- a/coregrind/m_syswrap/syswrap-arm64-linux.c
+++ b/coregrind/m_syswrap/syswrap-arm64-linux.c
@@ -835,6 +835,8 @@ static SyscallTableEntry syscall_main_table[] = {
    LINXY(__NR_close_range,       sys_close_range),       // 436
 
    LINX_(__NR_faccessat2,        sys_faccessat2),        // 439
+
+   LINXY(__NR_memfd_secret,      sys_memfd_secret),      // 447
 };
 
 
diff --git a/coregrind/m_syswrap/syswrap-linux.c b/coregrind/m_syswrap/syswrap-linux.c
index e2fafd4213..70aaec2f2d 100644
--- a/coregrind/m_syswrap/syswrap-linux.c
+++ b/coregrind/m_syswrap/syswrap-linux.c
@@ -4116,6 +4116,24 @@ POST(sys_memfd_create)
    }
 }
 
+PRE(sys_memfd_secret)
+{
+   PRINT("sys_memfd_secret ( %#" FMT_REGWORD "x )", ARG1);
+   PRE_REG_READ1(int, "memfd_secret", unsigned int, flags);
+}
+
+POST(sys_memfd_secret)
+{
+   vg_assert(SUCCESS);
+   if (!ML_(fd_allowed)(RES, "memfd_secret", tid, True)) {
+      VG_(close)(RES);
+      SET_STATUS_Failure( VKI_EMFILE );
+   } else {
+      if (VG_(clo_track_fds))
+         ML_(record_fd_open_nameless)(tid, RES);
+   }
+}
+
 PRE(sys_membarrier)
 {
    PRINT("sys_membarrier ( %#" FMT_REGWORD "x )", ARG1);
diff --git a/coregrind/m_syswrap/syswrap-x86-linux.c b/coregrind/m_syswrap/syswrap-x86-linux.c
index 8662ff501a..120cefc77a 100644
--- a/coregrind/m_syswrap/syswrap-x86-linux.c
+++ b/coregrind/m_syswrap/syswrap-x86-linux.c
@@ -1651,6 +1651,8 @@ static SyscallTableEntry syscall_table[] = {
    LINXY(__NR_close_range,       sys_close_range),      // 436
 
    LINX_(__NR_faccessat2,	 sys_faccessat2),       // 439
+
+   LINXY(__NR_memfd_secret,      sys_memfd_secret),      // 447
 };
 
 SyscallTableEntry* ML_(get_linux_syscall_entry) ( UInt sysno )
diff --git a/include/vki/vki-scnums-shared-linux.h b/include/vki/vki-scnums-shared-linux.h
index fa63c7a9bc..f591611f6d 100644
--- a/include/vki/vki-scnums-shared-linux.h
+++ b/include/vki/vki-scnums-shared-linux.h
@@ -44,4 +44,6 @@
 
 #define __NR_faccessat2		439
 
+#define __NR_memfd_secret		447
+
 #endif