From 6f4594d5dc61bb67978c44cd6eeb0e7bfb621c9b Mon Sep 17 00:00:00 2001
From: Elliott Hughes <enh@google.com>
Date: Wed, 26 Aug 2015 13:27:43 -0700
Subject: [PATCH] Add preadv/pwritev.
Bug: http://b/12612572
Change-Id: I38ff2684d69bd0fe3f21b1d371b88fa60d5421cb
---
libc/SYSCALLS.TXT | 10 +++++
libc/arch-arm/syscalls/__preadv64.S | 22 +++++++++++
libc/arch-arm/syscalls/__pwritev64.S | 22 +++++++++++
libc/arch-arm64/syscalls/preadv.S | 16 ++++++++
libc/arch-arm64/syscalls/pwritev.S | 16 ++++++++
libc/arch-mips/syscalls/__preadv64.S | 19 ++++++++++
libc/arch-mips/syscalls/__pwritev64.S | 19 ++++++++++
libc/arch-mips64/syscalls/preadv.S | 27 ++++++++++++++
libc/arch-mips64/syscalls/pwritev.S | 27 ++++++++++++++
libc/arch-x86/syscalls/__preadv64.S | 41 ++++++++++++++++++++
libc/arch-x86/syscalls/__pwritev64.S | 41 ++++++++++++++++++++
libc/arch-x86_64/syscalls/preadv.S | 18 +++++++++
libc/arch-x86_64/syscalls/pwritev.S | 18 +++++++++
libc/bionic/legacy_32_bit_support.cpp | 20 ++++++++++
libc/include/sys/uio.h | 12 ++++++
libc/libc.map | 4 ++
tests/sys_uio_test.cpp | 54 ++++++++++++++++++++++++++-
17 files changed, 384 insertions(+), 2 deletions(-)
create mode 100644 libc/arch-arm/syscalls/__preadv64.S
create mode 100644 libc/arch-arm/syscalls/__pwritev64.S
create mode 100644 libc/arch-arm64/syscalls/preadv.S
create mode 100644 libc/arch-arm64/syscalls/pwritev.S
create mode 100644 libc/arch-mips/syscalls/__preadv64.S
create mode 100644 libc/arch-mips/syscalls/__pwritev64.S
create mode 100644 libc/arch-mips64/syscalls/preadv.S
create mode 100644 libc/arch-mips64/syscalls/pwritev.S
create mode 100644 libc/arch-x86/syscalls/__preadv64.S
create mode 100644 libc/arch-x86/syscalls/__pwritev64.S
create mode 100644 libc/arch-x86_64/syscalls/preadv.S
create mode 100644 libc/arch-x86_64/syscalls/pwritev.S
diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index ac8db62e0..4188c1518 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -94,6 +94,16 @@ ssize_t pread64(int, void*, size_t, off64_t) arm,mips,x86
ssize_t pread64|pread(int, void*, size_t, off_t) arm64,mips64,x86_64
ssize_t pwrite64(int, void*, size_t, off64_t) arm,mips,x86
ssize_t pwrite64|pwrite(int, void*, size_t, off_t) arm64,mips64,x86_64
+
+# On LP32, preadv/pwritev don't use off64_t --- they use pairs of 32-bit
+# arguments to avoid problems on architectures like ARM where 64-bit arguments
+# must be in a register pair starting with an even-numbered register.
+# See linux/fs/read_write.c and https://lwn.net/Articles/311630/.
+ssize_t __preadv64:preadv(int, const struct iovec*, int, long, long) arm,mips,x86
+ssize_t preadv|preadv64(int, const struct iovec*, int, off_t) arm64,mips64,x86_64
+ssize_t __pwritev64:pwritev(int, const struct iovec*, int, long, long) arm,mips,x86
+ssize_t pwritev|pwritev64(int, const struct iovec*, int, off_t) arm64,mips64,x86_64
+
int ___close:close(int) all
pid_t __getpid:getpid() all
int munmap(void*, size_t) all
diff --git a/libc/arch-arm/syscalls/__preadv64.S b/libc/arch-arm/syscalls/__preadv64.S
new file mode 100644
index 000000000..19eaaa54e
--- /dev/null
+++ b/libc/arch-arm/syscalls/__preadv64.S
@@ -0,0 +1,22 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(__preadv64)
+ mov ip, sp
+ stmfd sp!, {r4, r5, r6, r7}
+ .cfi_def_cfa_offset 16
+ .cfi_rel_offset r4, 0
+ .cfi_rel_offset r5, 4
+ .cfi_rel_offset r6, 8
+ .cfi_rel_offset r7, 12
+ ldmfd ip, {r4, r5, r6}
+ ldr r7, =__NR_preadv
+ swi #0
+ ldmfd sp!, {r4, r5, r6, r7}
+ .cfi_def_cfa_offset 0
+ cmn r0, #(MAX_ERRNO + 1)
+ bxls lr
+ neg r0, r0
+ b __set_errno_internal
+END(__preadv64)
diff --git a/libc/arch-arm/syscalls/__pwritev64.S b/libc/arch-arm/syscalls/__pwritev64.S
new file mode 100644
index 000000000..afcbe403e
--- /dev/null
+++ b/libc/arch-arm/syscalls/__pwritev64.S
@@ -0,0 +1,22 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(__pwritev64)
+ mov ip, sp
+ stmfd sp!, {r4, r5, r6, r7}
+ .cfi_def_cfa_offset 16
+ .cfi_rel_offset r4, 0
+ .cfi_rel_offset r5, 4
+ .cfi_rel_offset r6, 8
+ .cfi_rel_offset r7, 12
+ ldmfd ip, {r4, r5, r6}
+ ldr r7, =__NR_pwritev
+ swi #0
+ ldmfd sp!, {r4, r5, r6, r7}
+ .cfi_def_cfa_offset 0
+ cmn r0, #(MAX_ERRNO + 1)
+ bxls lr
+ neg r0, r0
+ b __set_errno_internal
+END(__pwritev64)
diff --git a/libc/arch-arm64/syscalls/preadv.S b/libc/arch-arm64/syscalls/preadv.S
new file mode 100644
index 000000000..cb8300d51
--- /dev/null
+++ b/libc/arch-arm64/syscalls/preadv.S
@@ -0,0 +1,16 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(preadv)
+ mov x8, __NR_preadv
+ svc #0
+
+ cmn x0, #(MAX_ERRNO + 1)
+ cneg x0, x0, hi
+ b.hi __set_errno_internal
+
+ ret
+END(preadv)
+
+ALIAS_SYMBOL(preadv64, preadv)
diff --git a/libc/arch-arm64/syscalls/pwritev.S b/libc/arch-arm64/syscalls/pwritev.S
new file mode 100644
index 000000000..621466a6a
--- /dev/null
+++ b/libc/arch-arm64/syscalls/pwritev.S
@@ -0,0 +1,16 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(pwritev)
+ mov x8, __NR_pwritev
+ svc #0
+
+ cmn x0, #(MAX_ERRNO + 1)
+ cneg x0, x0, hi
+ b.hi __set_errno_internal
+
+ ret
+END(pwritev)
+
+ALIAS_SYMBOL(pwritev64, pwritev)
diff --git a/libc/arch-mips/syscalls/__preadv64.S b/libc/arch-mips/syscalls/__preadv64.S
new file mode 100644
index 000000000..a46b86983
--- /dev/null
+++ b/libc/arch-mips/syscalls/__preadv64.S
@@ -0,0 +1,19 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(__preadv64)
+ .set noreorder
+ .cpload t9
+ li v0, __NR_preadv
+ syscall
+ bnez a3, 1f
+ move a0, v0
+ j ra
+ nop
+1:
+ la t9,__set_errno_internal
+ j t9
+ nop
+ .set reorder
+END(__preadv64)
diff --git a/libc/arch-mips/syscalls/__pwritev64.S b/libc/arch-mips/syscalls/__pwritev64.S
new file mode 100644
index 000000000..1222942f2
--- /dev/null
+++ b/libc/arch-mips/syscalls/__pwritev64.S
@@ -0,0 +1,19 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(__pwritev64)
+ .set noreorder
+ .cpload t9
+ li v0, __NR_pwritev
+ syscall
+ bnez a3, 1f
+ move a0, v0
+ j ra
+ nop
+1:
+ la t9,__set_errno_internal
+ j t9
+ nop
+ .set reorder
+END(__pwritev64)
diff --git a/libc/arch-mips64/syscalls/preadv.S b/libc/arch-mips64/syscalls/preadv.S
new file mode 100644
index 000000000..df43a8dc1
--- /dev/null
+++ b/libc/arch-mips64/syscalls/preadv.S
@@ -0,0 +1,27 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(preadv)
+ .set push
+ .set noreorder
+ li v0, __NR_preadv
+ syscall
+ bnez a3, 1f
+ move a0, v0
+ j ra
+ nop
+1:
+ move t0, ra
+ bal 2f
+ nop
+2:
+ .cpsetup ra, t1, 2b
+ LA t9,__set_errno_internal
+ .cpreturn
+ j t9
+ move ra, t0
+ .set pop
+END(preadv)
+
+ALIAS_SYMBOL(preadv64, preadv)
diff --git a/libc/arch-mips64/syscalls/pwritev.S b/libc/arch-mips64/syscalls/pwritev.S
new file mode 100644
index 000000000..f55cec02b
--- /dev/null
+++ b/libc/arch-mips64/syscalls/pwritev.S
@@ -0,0 +1,27 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(pwritev)
+ .set push
+ .set noreorder
+ li v0, __NR_pwritev
+ syscall
+ bnez a3, 1f
+ move a0, v0
+ j ra
+ nop
+1:
+ move t0, ra
+ bal 2f
+ nop
+2:
+ .cpsetup ra, t1, 2b
+ LA t9,__set_errno_internal
+ .cpreturn
+ j t9
+ move ra, t0
+ .set pop
+END(pwritev)
+
+ALIAS_SYMBOL(pwritev64, pwritev)
diff --git a/libc/arch-x86/syscalls/__preadv64.S b/libc/arch-x86/syscalls/__preadv64.S
new file mode 100644
index 000000000..3ce4fc3d9
--- /dev/null
+++ b/libc/arch-x86/syscalls/__preadv64.S
@@ -0,0 +1,41 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(__preadv64)
+ pushl %ebx
+ .cfi_def_cfa_offset 8
+ .cfi_rel_offset ebx, 0
+ pushl %ecx
+ .cfi_adjust_cfa_offset 4
+ .cfi_rel_offset ecx, 0
+ pushl %edx
+ .cfi_adjust_cfa_offset 4
+ .cfi_rel_offset edx, 0
+ pushl %esi
+ .cfi_adjust_cfa_offset 4
+ .cfi_rel_offset esi, 0
+ pushl %edi
+ .cfi_adjust_cfa_offset 4
+ .cfi_rel_offset edi, 0
+ mov 24(%esp), %ebx
+ mov 28(%esp), %ecx
+ mov 32(%esp), %edx
+ mov 36(%esp), %esi
+ mov 40(%esp), %edi
+ movl $__NR_preadv, %eax
+ int $0x80
+ cmpl $-MAX_ERRNO, %eax
+ jb 1f
+ negl %eax
+ pushl %eax
+ call __set_errno_internal
+ addl $4, %esp
+1:
+ popl %edi
+ popl %esi
+ popl %edx
+ popl %ecx
+ popl %ebx
+ ret
+END(__preadv64)
diff --git a/libc/arch-x86/syscalls/__pwritev64.S b/libc/arch-x86/syscalls/__pwritev64.S
new file mode 100644
index 000000000..2ce5b0ee5
--- /dev/null
+++ b/libc/arch-x86/syscalls/__pwritev64.S
@@ -0,0 +1,41 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(__pwritev64)
+ pushl %ebx
+ .cfi_def_cfa_offset 8
+ .cfi_rel_offset ebx, 0
+ pushl %ecx
+ .cfi_adjust_cfa_offset 4
+ .cfi_rel_offset ecx, 0
+ pushl %edx
+ .cfi_adjust_cfa_offset 4
+ .cfi_rel_offset edx, 0
+ pushl %esi
+ .cfi_adjust_cfa_offset 4
+ .cfi_rel_offset esi, 0
+ pushl %edi
+ .cfi_adjust_cfa_offset 4
+ .cfi_rel_offset edi, 0
+ mov 24(%esp), %ebx
+ mov 28(%esp), %ecx
+ mov 32(%esp), %edx
+ mov 36(%esp), %esi
+ mov 40(%esp), %edi
+ movl $__NR_pwritev, %eax
+ int $0x80
+ cmpl $-MAX_ERRNO, %eax
+ jb 1f
+ negl %eax
+ pushl %eax
+ call __set_errno_internal
+ addl $4, %esp
+1:
+ popl %edi
+ popl %esi
+ popl %edx
+ popl %ecx
+ popl %ebx
+ ret
+END(__pwritev64)
diff --git a/libc/arch-x86_64/syscalls/preadv.S b/libc/arch-x86_64/syscalls/preadv.S
new file mode 100644
index 000000000..7771a4447
--- /dev/null
+++ b/libc/arch-x86_64/syscalls/preadv.S
@@ -0,0 +1,18 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(preadv)
+ movq %rcx, %r10
+ movl $__NR_preadv, %eax
+ syscall
+ cmpq $-MAX_ERRNO, %rax
+ jb 1f
+ negl %eax
+ movl %eax, %edi
+ call __set_errno_internal
+1:
+ ret
+END(preadv)
+
+ALIAS_SYMBOL(preadv64, preadv)
diff --git a/libc/arch-x86_64/syscalls/pwritev.S b/libc/arch-x86_64/syscalls/pwritev.S
new file mode 100644
index 000000000..d3bd8facb
--- /dev/null
+++ b/libc/arch-x86_64/syscalls/pwritev.S
@@ -0,0 +1,18 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(pwritev)
+ movq %rcx, %r10
+ movl $__NR_pwritev, %eax
+ syscall
+ cmpq $-MAX_ERRNO, %rax
+ jb 1f
+ negl %eax
+ movl %eax, %edi
+ call __set_errno_internal
+1:
+ ret
+END(pwritev)
+
+ALIAS_SYMBOL(pwritev64, pwritev)
diff --git a/libc/bionic/legacy_32_bit_support.cpp b/libc/bionic/legacy_32_bit_support.cpp
index a10766471..20d258d7d 100644
--- a/libc/bionic/legacy_32_bit_support.cpp
+++ b/libc/bionic/legacy_32_bit_support.cpp
@@ -33,6 +33,7 @@
#include <stdarg.h>
#include <sys/resource.h>
#include <sys/types.h>
+#include <sys/uio.h>
#include <sys/vfs.h>
#include <unistd.h>
@@ -43,6 +44,8 @@
// System calls we need.
extern "C" int __fcntl64(int, int, void*);
extern "C" int __llseek(int, unsigned long, unsigned long, off64_t*, int);
+extern "C" int __preadv64(int, const struct iovec*, int, long, long);
+extern "C" int __pwritev64(int, const struct iovec*, int, long, long);
// For fcntl we use the fcntl64 system call to signal that we're using struct flock64.
int fcntl(int fd, int cmd, ...) {
@@ -77,6 +80,23 @@ ssize_t pwrite(int fd, const void* buf, size_t byte_count, off_t offset) {
return pwrite64(fd, buf, byte_count, static_cast<off64_t>(offset));
}
+// On LP32, there is no off_t preadv/pwritev, and even the 64-bit preadv/pwritev
+// don't use off64_t (see SYSCALLS.TXT for more). Here, this means that we need
+// to implement all four functions because the two system calls don't match any
+// of the userspace functions. Unlike llseek, the pair is split lo-hi, not hi-lo.
+ssize_t preadv(int fd, const struct iovec* ios, int count, off_t offset) {
+ return __preadv64(fd, ios, count, offset, 0);
+}
+ssize_t preadv64(int fd, const struct iovec* ios, int count, off64_t offset) {
+ return __preadv64(fd, ios, count, offset, offset >> 32);
+}
+ssize_t pwritev(int fd, const struct iovec* ios, int count, off_t offset) {
+ return __pwritev64(fd, ios, count, offset, 0);
+}
+ssize_t pwritev64(int fd, const struct iovec* ios, int count, off64_t offset) {
+ return __pwritev64(fd, ios, count, offset, offset >> 32);
+}
+
// There is no fallocate for 32-bit off_t, so we need to widen and call fallocate64.
int fallocate(int fd, int mode, off_t offset, off_t length) {
return fallocate64(fd, mode, static_cast<off64_t>(offset), static_cast<off64_t>(length));
diff --git a/libc/include/sys/uio.h b/libc/include/sys/uio.h
index 187ec22a4..72675d127 100644
--- a/libc/include/sys/uio.h
+++ b/libc/include/sys/uio.h
@@ -37,6 +37,18 @@ __BEGIN_DECLS
int readv(int, const struct iovec*, int);
int writev(int, const struct iovec*, int);
+#if defined(__USE_GNU)
+#if defined(__USE_FILE_OFFSET64)
+ssize_t preadv(int, const struct iovec*, int, off_t) __RENAME(preadv64);
+ssize_t pwritev(int, const struct iovec*, int, off_t) __RENAME(pwritev64);
+#else
+ssize_t preadv(int, const struct iovec*, int, off_t);
+ssize_t pwritev(int, const struct iovec*, int, off_t);
+#endif
+ssize_t preadv64(int, const struct iovec*, int, off64_t);
+ssize_t pwritev64(int, const struct iovec*, int, off64_t);
+#endif
+
#if defined(__USE_GNU)
ssize_t process_vm_readv(pid_t, const struct iovec*, unsigned long, const struct iovec*, unsigned long, unsigned long);
ssize_t process_vm_writev(pid_t, const struct iovec*, unsigned long, const struct iovec*, unsigned long, unsigned long);
diff --git a/libc/libc.map b/libc/libc.map
index 945692050..fbceb832a 100644
--- a/libc/libc.map
+++ b/libc/libc.map
@@ -1342,6 +1342,10 @@ LIBC_N {
__write_chk;
getgrgid_r;
getgrnam_r;
+ preadv;
+ preadv64;
+ pwritev;
+ pwritev64;
strchrnul;
} LIBC;
diff --git a/tests/sys_uio_test.cpp b/tests/sys_uio_test.cpp
index c7af8a77c..569d4fbad 100644
--- a/tests/sys_uio_test.cpp
+++ b/tests/sys_uio_test.cpp
@@ -18,10 +18,60 @@
#include <sys/uio.h>
-TEST(sys_uio, process_vm_readv_ESRCH) {
+#include "TemporaryFile.h"
+
+TEST(sys_uio, readv_writev) {
+ TemporaryFile tf;
+
+ char buf1[] = "hello";
+ char buf2[] = "world";
+ iovec ios[] = { { buf1, 5 }, { buf2, 5 } };
+
+ ASSERT_EQ(10, writev(tf.fd, ios, 2));
+
+ ASSERT_EQ(0, lseek(tf.fd, 0, SEEK_SET));
+
+ memset(buf1, '1', sizeof(buf1));
+ memset(buf2, '2', sizeof(buf2));
+
+ ASSERT_EQ(10, readv(tf.fd, ios, 2));
+ buf1[5] = buf2[5] = '\0';
+ ASSERT_STREQ("hello", buf1);
+ ASSERT_STREQ("world", buf2);
+}
+
+template <typename ReadFn, typename WriteFn>
+void TestPreadVPwriteV(ReadFn read_fn, WriteFn write_fn) {
+ TemporaryFile tf;
+
+ char buf[] = "world";
+ iovec ios[] = { { buf, 5 } };
+
+ ASSERT_EQ(5, write_fn(tf.fd, ios, 1, 5));
+ ASSERT_EQ(0, lseek(tf.fd, 0, SEEK_CUR));
+
+ strcpy(buf, "hello");
+ ASSERT_EQ(5, write_fn(tf.fd, ios, 1, 0));
+ ASSERT_EQ(0, lseek(tf.fd, 0, SEEK_CUR));
+
+ ASSERT_EQ(5, read_fn(tf.fd, ios, 1, 5));
+ ASSERT_STREQ("world", buf);
+ ASSERT_EQ(5, read_fn(tf.fd, ios, 1, 0));
+ ASSERT_STREQ("hello", buf);
+}
+
+TEST(sys_uio, preadv_pwritev) {
+ TestPreadVPwriteV(preadv, pwritev);
+}
+
+TEST(sys_uio, preadv64_pwritev64) {
+ TestPreadVPwriteV(preadv64, pwritev64);
+}
+
+TEST(sys_uio, process_vm_readv) {
ASSERT_EQ(0, process_vm_readv(0, nullptr, 0, nullptr, 0, 0));
}
-TEST(sys_uio, process_vm_writev_ESRCH) {
+TEST(sys_uio, process_vm_writev) {
ASSERT_EQ(0, process_vm_writev(0, nullptr, 0, nullptr, 0, 0));
}