From 1024237358f01009fe233cb1294f3b8211304eaa Mon Sep 17 00:00:00 2001
From: Mark Wielaard <mark@klomp.org>
Date: Fri, 10 Dec 2021 17:41:59 +0100
Subject: [PATCH] Implement linux rseq syscall as ENOSYS

This implements rseq for amd64, arm, arm64, ppc32, ppc64,
s390x and x86 linux as ENOSYS (without warning).

glibc will start using rseq to accelerate sched_getcpu, if
available. This would cause a warning from valgrind every
time a new thread is started.

Real rseq (restartable sequences) support is pretty hard, so
for now just explicitly return ENOSYS (just like we do for clone3).

https://sourceware.org/pipermail/libc-alpha/2021-December/133656.html
---
 coregrind/m_syswrap/syswrap-amd64-linux.c | 2 ++
 coregrind/m_syswrap/syswrap-arm-linux.c   | 1 +
 coregrind/m_syswrap/syswrap-arm64-linux.c | 3 ++-
 coregrind/m_syswrap/syswrap-ppc32-linux.c | 2 ++
 coregrind/m_syswrap/syswrap-ppc64-linux.c | 2 ++
 coregrind/m_syswrap/syswrap-s390x-linux.c | 2 ++
 coregrind/m_syswrap/syswrap-x86-linux.c   | 2 ++
 include/vki/vki-scnums-arm-linux.h        | 1 +
 include/vki/vki-scnums-arm64-linux.h      | 4 +++-
 include/vki/vki-scnums-ppc32-linux.h      | 1 +
 include/vki/vki-scnums-ppc64-linux.h      | 1 +
 include/vki/vki-scnums-s390x-linux.h      | 5 ++++-
 12 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/coregrind/m_syswrap/syswrap-amd64-linux.c b/coregrind/m_syswrap/syswrap-amd64-linux.c
index 5062324a1e..18b25f80ae 100644
--- a/coregrind/m_syswrap/syswrap-amd64-linux.c
+++ b/coregrind/m_syswrap/syswrap-amd64-linux.c
@@ -862,6 +862,8 @@ static SyscallTableEntry syscall_table[] = {
 
    LINXY(__NR_statx,             sys_statx),             // 332
 
+   GENX_(__NR_rseq,              sys_ni_syscall),        // 334
+
    LINX_(__NR_membarrier,        sys_membarrier),        // 324
 
    LINX_(__NR_copy_file_range,   sys_copy_file_range),   // 326
diff --git a/coregrind/m_syswrap/syswrap-arm-linux.c b/coregrind/m_syswrap/syswrap-arm-linux.c
index 556dd844b9..d583cef0c7 100644
--- a/coregrind/m_syswrap/syswrap-arm-linux.c
+++ b/coregrind/m_syswrap/syswrap-arm-linux.c
@@ -1024,6 +1024,7 @@ static SyscallTableEntry syscall_main_table[] = {
    LINX_(__NR_pwritev2,          sys_pwritev2),         // 393
 
    LINXY(__NR_statx,             sys_statx),            // 397
+   GENX_(__NR_rseq,              sys_ni_syscall),       // 398
 
    LINXY(__NR_clock_gettime64,   sys_clock_gettime64),  // 403
    LINX_(__NR_clock_settime64,   sys_clock_settime64),  // 404
diff --git a/coregrind/m_syswrap/syswrap-arm64-linux.c b/coregrind/m_syswrap/syswrap-arm64-linux.c
index b871077276..2066a38ea9 100644
--- a/coregrind/m_syswrap/syswrap-arm64-linux.c
+++ b/coregrind/m_syswrap/syswrap-arm64-linux.c
@@ -823,8 +823,9 @@ static SyscallTableEntry syscall_main_table[] = {
    //   (__NR_pkey_mprotect,     sys_ni_syscall),        // 288
    //   (__NR_pkey_alloc,        sys_ni_syscall),        // 289
    //   (__NR_pkey_free,         sys_ni_syscall),        // 290
+   LINXY(__NR_statx,             sys_statx),             // 291
 
-   LINXY(__NR_statx,             sys_statx),             // 397
+   GENX_(__NR_rseq,              sys_ni_syscall),        // 293
 
    LINXY(__NR_io_uring_setup,    sys_io_uring_setup),    // 425
    LINXY(__NR_io_uring_enter,    sys_io_uring_enter),    // 426
diff --git a/coregrind/m_syswrap/syswrap-ppc32-linux.c b/coregrind/m_syswrap/syswrap-ppc32-linux.c
index 6263ab8451..637b2504e1 100644
--- a/coregrind/m_syswrap/syswrap-ppc32-linux.c
+++ b/coregrind/m_syswrap/syswrap-ppc32-linux.c
@@ -1028,6 +1028,8 @@ static SyscallTableEntry syscall_table[] = {
 
    LINXY(__NR_statx,             sys_statx),            // 383
 
+   GENX_(__NR_rseq,              sys_ni_syscall),       // 387
+
    LINXY(__NR_clock_gettime64,   sys_clock_gettime64),  // 403
    LINX_(__NR_clock_settime64,   sys_clock_settime64),  // 404
 
diff --git a/coregrind/m_syswrap/syswrap-ppc64-linux.c b/coregrind/m_syswrap/syswrap-ppc64-linux.c
index a26b41c321..93956d3cc2 100644
--- a/coregrind/m_syswrap/syswrap-ppc64-linux.c
+++ b/coregrind/m_syswrap/syswrap-ppc64-linux.c
@@ -1019,6 +1019,8 @@ static SyscallTableEntry syscall_table[] = {
 
    LINXY(__NR_statx,             sys_statx),            // 383
 
+   GENX_(__NR_rseq,              sys_ni_syscall),       // 387
+
    LINXY(__NR_io_uring_setup,    sys_io_uring_setup),    // 425
    LINXY(__NR_io_uring_enter,    sys_io_uring_enter),    // 426
    LINXY(__NR_io_uring_register, sys_io_uring_register), // 427
diff --git a/coregrind/m_syswrap/syswrap-s390x-linux.c b/coregrind/m_syswrap/syswrap-s390x-linux.c
index 5c9209859f..73f9684c46 100644
--- a/coregrind/m_syswrap/syswrap-s390x-linux.c
+++ b/coregrind/m_syswrap/syswrap-s390x-linux.c
@@ -860,6 +860,8 @@ static SyscallTableEntry syscall_table[] = {
 
    LINXY(__NR_statx, sys_statx),                                      // 379
 
+   GENX_(__NR_rseq, sys_ni_syscall),                                  // 381
+
    LINXY(__NR_io_uring_setup, sys_io_uring_setup),                    // 425
    LINXY(__NR_io_uring_enter, sys_io_uring_enter),                    // 426
    LINXY(__NR_io_uring_register, sys_io_uring_register),              // 427
diff --git a/coregrind/m_syswrap/syswrap-x86-linux.c b/coregrind/m_syswrap/syswrap-x86-linux.c
index 1d8f45d33a..8662ff501a 100644
--- a/coregrind/m_syswrap/syswrap-x86-linux.c
+++ b/coregrind/m_syswrap/syswrap-x86-linux.c
@@ -1619,6 +1619,8 @@ static SyscallTableEntry syscall_table[] = {
    /* Explicitly not supported on i386 yet. */
    GENX_(__NR_arch_prctl,        sys_ni_syscall),       // 384
 
+   GENX_(__NR_rseq,              sys_ni_syscall),       // 386
+
    LINXY(__NR_clock_gettime64,   sys_clock_gettime64),  // 403
    LINX_(__NR_clock_settime64,   sys_clock_settime64),  // 404
 
diff --git a/include/vki/vki-scnums-arm-linux.h b/include/vki/vki-scnums-arm-linux.h
index ff560e19dd..485db8b265 100644
--- a/include/vki/vki-scnums-arm-linux.h
+++ b/include/vki/vki-scnums-arm-linux.h
@@ -432,6 +432,7 @@
 #define __NR_pkey_alloc                 395
 #define __NR_pkey_free                  396
 #define __NR_statx                      397
+#define __NR_rseq                       398
 
 
 
diff --git a/include/vki/vki-scnums-arm64-linux.h b/include/vki/vki-scnums-arm64-linux.h
index 9aa3b2b5fb..acdfb39c68 100644
--- a/include/vki/vki-scnums-arm64-linux.h
+++ b/include/vki/vki-scnums-arm64-linux.h
@@ -323,9 +323,11 @@
 #define __NR_pkey_alloc 289
 #define __NR_pkey_free 290
 #define __NR_statx 291
+#define __NR_io_pgetevents 291
+#define __NR_rseq 293
 
 #undef __NR_syscalls
-#define __NR_syscalls 292
+#define __NR_syscalls 294
 
 ///*
 // * All syscalls below here should go away really,
diff --git a/include/vki/vki-scnums-ppc32-linux.h b/include/vki/vki-scnums-ppc32-linux.h
index 6987ad941b..08fa77df0d 100644
--- a/include/vki/vki-scnums-ppc32-linux.h
+++ b/include/vki/vki-scnums-ppc32-linux.h
@@ -415,6 +415,7 @@
 #define __NR_pkey_alloc		384
 #define __NR_pkey_free		385
 #define __NR_pkey_mprotect	386
+#define __NR_rseq		387
 
 #endif /* __VKI_SCNUMS_PPC32_LINUX_H */
 
diff --git a/include/vki/vki-scnums-ppc64-linux.h b/include/vki/vki-scnums-ppc64-linux.h
index 6827964fdf..a76fa6d322 100644
--- a/include/vki/vki-scnums-ppc64-linux.h
+++ b/include/vki/vki-scnums-ppc64-linux.h
@@ -407,6 +407,7 @@
 #define __NR_pkey_alloc		384
 #define __NR_pkey_free		385
 #define __NR_pkey_mprotect	386
+#define __NR_rseq		387
 
 #endif /* __VKI_SCNUMS_PPC64_LINUX_H */
 
diff --git a/include/vki/vki-scnums-s390x-linux.h b/include/vki/vki-scnums-s390x-linux.h
index 6487e20c99..869c045847 100644
--- a/include/vki/vki-scnums-s390x-linux.h
+++ b/include/vki/vki-scnums-s390x-linux.h
@@ -342,8 +342,11 @@
 #define __NR_s390_guarded_storage	378
 #define __NR_statx			379
 #define __NR_s390_sthyi			380
+#define __NR_kexec_file_load		381
+#define __NR_io_pgetevents		382
+#define __NR_rseq			383
 
-#define NR_syscalls 381
+#define NR_syscalls 384
 
 /* 
  * There are some system calls that are not present on 64 bit, some
-- 
2.27.0

