commit 10726d52ac3a7b34a6e2d9c40532037ca1108485
author Robert Jarzmik <robert.jarzmik@intel.com> Wed Jul 15 15:26:43 2015 +0200
committer Mingwei Shi <mingwei.shi@intel.com> Wed Jul 22 01:31:38 2015 +0000
tree 49c3613ab638c4f7f322d4ad5d95dfbbd7b82fd2
parent 3bcfd47c6836a952b2093c64feb9f1e382891256

libc: arch-x86: implement kernel vdso time functions

This patch give the possibility of time vdso support on 32bit kernel.
If the 32bit x86 kernel provides gettimeofday() and clock_gettime()
primitives in vdso. In this case make bionic use them. If the kernel
doesn't provide them, fallback to the legacy system call versions.

Change-Id: I87b772a9486fa356903e1f98f486ab9eb0b6f6f7
Signed-off-by: Robert Jarzmik <robert.jarzmik@intel.com>
Signed-off-by: Mingwei Shi <mingwei.shi@intel.com>

libc/SYSCALLS.TXT

diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index 151749b..f81b89f 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -333,7 +333,7 @@
 int     __set_thread_area:set_thread_area(void*) x86
 
 # vdso stuff.
-int clock_gettime(clockid_t, timespec*)                 arm,mips,mips64,x86
-int __clock_gettime:clock_gettime(clockid_t, timespec*) arm64,x86_64
-int gettimeofday(timeval*, timezone*)                   arm,mips,mips64,x86
-int __gettimeofday:gettimeofday(timeval*, timezone*)    arm64,x86_64
+int clock_gettime(clockid_t, timespec*)                 arm,mips,mips64
+int __clock_gettime:clock_gettime(clockid_t, timespec*) arm64,x86,x86_64
+int gettimeofday(timeval*, timezone*)                   arm,mips,mips64
+int __gettimeofday:gettimeofday(timeval*, timezone*)    arm64,x86,x86_64

libc/arch-x86/syscalls/__clock_gettime.S

diff --git a/libc/arch-x86/syscalls/clock_gettime.S b/libc/arch-x86/syscalls/__clock_gettime.S
similarity index 92%
rename from libc/arch-x86/syscalls/clock_gettime.S
rename to libc/arch-x86/syscalls/__clock_gettime.S
index 0875cfb..61eadc8 100644
--- a/libc/arch-x86/syscalls/clock_gettime.S
+++ b/libc/arch-x86/syscalls/__clock_gettime.S
@@ -2,7 +2,7 @@
 
 #include <private/bionic_asm.h>
 
-ENTRY(clock_gettime)
+ENTRY(__clock_gettime)
     pushl   %ebx
     .cfi_def_cfa_offset 8
     .cfi_rel_offset ebx, 0
@@ -23,4 +23,4 @@
     popl    %ecx
     popl    %ebx
     ret
-END(clock_gettime)
+END(__clock_gettime)

libc/arch-x86/syscalls/__gettimeofday.S

diff --git a/libc/arch-x86/syscalls/gettimeofday.S b/libc/arch-x86/syscalls/__gettimeofday.S
similarity index 92%
rename from libc/arch-x86/syscalls/gettimeofday.S
rename to libc/arch-x86/syscalls/__gettimeofday.S
index a508c14..90f3f91 100644
--- a/libc/arch-x86/syscalls/gettimeofday.S
+++ b/libc/arch-x86/syscalls/__gettimeofday.S
@@ -2,7 +2,7 @@
 
 #include <private/bionic_asm.h>
 
-ENTRY(gettimeofday)
+ENTRY(__gettimeofday)
     pushl   %ebx
     .cfi_def_cfa_offset 8
     .cfi_rel_offset ebx, 0
@@ -23,4 +23,4 @@
     popl    %ecx
     popl    %ebx
     ret
-END(gettimeofday)
+END(__gettimeofday)

libc/bionic/vdso.cpp

diff --git a/libc/bionic/vdso.cpp b/libc/bionic/vdso.cpp
index b55c57f..9eae3d5 100644
--- a/libc/bionic/vdso.cpp
+++ b/libc/bionic/vdso.cpp
@@ -19,13 +19,12 @@
 #include <sys/auxv.h>
 #include <unistd.h>
 
-// x86 has a vdso, but there's nothing useful to us in it.
-#if defined(__aarch64__) || defined(__x86_64__)
+#if defined(__aarch64__) || defined(__x86_64__) || defined (__i386__)
 
 #if defined(__aarch64__)
 #define VDSO_CLOCK_GETTIME_SYMBOL "__kernel_clock_gettime"
 #define VDSO_GETTIMEOFDAY_SYMBOL  "__kernel_gettimeofday"
-#elif defined(__x86_64__)
+#elif defined(__x86_64__) || defined(__i386__)
 #define VDSO_CLOCK_GETTIME_SYMBOL "__vdso_clock_gettime"
 #define VDSO_GETTIMEOFDAY_SYMBOL  "__vdso_gettimeofday"
 #endif