From 00490ae3f351e07ed4cc2a94b11cba6a22f37311 Mon Sep 17 00:00:00 2001
From: Nick Kralevich <nnk@google.com>
Date: Tue, 3 Feb 2015 11:27:25 -0800
Subject: [PATCH] Ensure raw fchmod/fchmodat syscalls are hidden.
In https://android-review.googlesource.com/#/c/127908/5/libc/SYSCALLS.TXT@116
Elliott said:
for LP64 these will be hidden. for LP32 we were cowards and left
them all public for compatibility (though i don't think we ever
dremeled to see whether it was needed). we don't have an easy
way to recognize additions, though, so we can't prevent adding
new turds.
Add a mechanism to prevent the adding of new turds, and use that
mechanism on the fchmod/fchmodat system calls.
Bug: 19233951
Change-Id: I98f98345970b631a379f348df57858f9fc3d57c0
---
libc/SYSCALLS.TXT | 4 ++--
libc/arch-arm/syscalls/{__fchmod.S => ___fchmod.S} | 5 +++--
libc/arch-arm/syscalls/{__fchmodat.S => ___fchmodat.S} | 5 +++--
libc/arch-arm64/syscalls/{__fchmod.S => ___fchmod.S} | 6 +++---
libc/arch-arm64/syscalls/{__fchmodat.S => ___fchmodat.S} | 6 +++---
libc/arch-mips/syscalls/{__fchmod.S => ___fchmod.S} | 5 +++--
libc/arch-mips/syscalls/{__fchmodat.S => ___fchmodat.S} | 5 +++--
libc/arch-mips64/syscalls/{__fchmod.S => ___fchmod.S} | 6 +++---
libc/arch-mips64/syscalls/{__fchmodat.S => ___fchmodat.S} | 6 +++---
libc/arch-x86/syscalls/{__fchmod.S => ___fchmod.S} | 5 +++--
libc/arch-x86/syscalls/{__fchmodat.S => ___fchmodat.S} | 5 +++--
libc/arch-x86_64/syscalls/{__fchmod.S => ___fchmod.S} | 6 +++---
libc/arch-x86_64/syscalls/{__fchmodat.S => ___fchmodat.S} | 6 +++---
libc/bionic/fchmod.cpp | 4 ++--
libc/bionic/fchmodat.cpp | 4 ++--
libc/tools/gensyscalls.py | 5 +++--
16 files changed, 45 insertions(+), 38 deletions(-)
rename libc/arch-arm/syscalls/{__fchmod.S => ___fchmod.S} (84%)
rename libc/arch-arm/syscalls/{__fchmodat.S => ___fchmodat.S} (82%)
rename libc/arch-arm64/syscalls/{__fchmod.S => ___fchmod.S} (81%)
rename libc/arch-arm64/syscalls/{__fchmodat.S => ___fchmodat.S} (80%)
rename libc/arch-mips/syscalls/{__fchmod.S => ___fchmod.S} (84%)
rename libc/arch-mips/syscalls/{__fchmodat.S => ___fchmodat.S} (82%)
rename libc/arch-mips64/syscalls/{__fchmod.S => ___fchmod.S} (87%)
rename libc/arch-mips64/syscalls/{__fchmodat.S => ___fchmodat.S} (86%)
rename libc/arch-x86/syscalls/{__fchmod.S => ___fchmod.S} (91%)
rename libc/arch-x86/syscalls/{__fchmodat.S => ___fchmodat.S} (91%)
rename libc/arch-x86_64/syscalls/{__fchmod.S => ___fchmod.S} (83%)
rename libc/arch-x86_64/syscalls/{__fchmodat.S => ___fchmodat.S} (82%)
diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index d68a00fd1..aae7de779 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -113,7 +113,7 @@ int writev(int, const struct iovec*, int) all
int __fcntl64:fcntl64(int, int, void*) arm,mips,x86
int fcntl(int, int, void*) arm64,mips64,x86_64
int flock(int, int) all
-int __fchmod:fchmod(int, mode_t) all
+int ___fchmod:fchmod(int, mode_t) all
int dup(int) all
int pipe2(int*, int) all
int dup3(int, int, int) all
@@ -131,7 +131,7 @@ int __getdents64:getdents64(unsigned int, struct dirent*, unsigned int) arm,ar
int __openat:openat(int, const char*, int, mode_t) all
int faccessat(int, const char*, int, int) all
-int __fchmodat:fchmodat(int, const char*, mode_t) all
+int ___fchmodat:fchmodat(int, const char*, mode_t) all
int fchownat(int, const char*, uid_t, gid_t, int) all
int fstatat64|fstatat:fstatat64(int, const char*, struct stat*, int) arm,mips,x86
int fstatat64|fstatat:newfstatat(int, const char*, struct stat*, int) arm64,x86_64
diff --git a/libc/arch-arm/syscalls/__fchmod.S b/libc/arch-arm/syscalls/___fchmod.S
similarity index 84%
rename from libc/arch-arm/syscalls/__fchmod.S
rename to libc/arch-arm/syscalls/___fchmod.S
index ff888a17e..c6da4f89e 100644
--- a/libc/arch-arm/syscalls/__fchmod.S
+++ b/libc/arch-arm/syscalls/___fchmod.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(__fchmod)
+ENTRY(___fchmod)
mov ip, r7
ldr r7, =__NR_fchmod
swi #0
@@ -11,4 +11,5 @@ ENTRY(__fchmod)
bxls lr
neg r0, r0
b __set_errno_internal
-END(__fchmod)
+END(___fchmod)
+.hidden ___fchmod
diff --git a/libc/arch-arm/syscalls/__fchmodat.S b/libc/arch-arm/syscalls/___fchmodat.S
similarity index 82%
rename from libc/arch-arm/syscalls/__fchmodat.S
rename to libc/arch-arm/syscalls/___fchmodat.S
index 4d10f00b8..91bbda5c0 100644
--- a/libc/arch-arm/syscalls/__fchmodat.S
+++ b/libc/arch-arm/syscalls/___fchmodat.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(__fchmodat)
+ENTRY(___fchmodat)
mov ip, r7
ldr r7, =__NR_fchmodat
swi #0
@@ -11,4 +11,5 @@ ENTRY(__fchmodat)
bxls lr
neg r0, r0
b __set_errno_internal
-END(__fchmodat)
+END(___fchmodat)
+.hidden ___fchmodat
diff --git a/libc/arch-arm64/syscalls/__fchmod.S b/libc/arch-arm64/syscalls/___fchmod.S
similarity index 81%
rename from libc/arch-arm64/syscalls/__fchmod.S
rename to libc/arch-arm64/syscalls/___fchmod.S
index 05c67fc37..a143c65f0 100644
--- a/libc/arch-arm64/syscalls/__fchmod.S
+++ b/libc/arch-arm64/syscalls/___fchmod.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(__fchmod)
+ENTRY(___fchmod)
mov x8, __NR_fchmod
svc #0
@@ -11,5 +11,5 @@ ENTRY(__fchmod)
b.hi __set_errno_internal
ret
-END(__fchmod)
-.hidden __fchmod
+END(___fchmod)
+.hidden ___fchmod
diff --git a/libc/arch-arm64/syscalls/__fchmodat.S b/libc/arch-arm64/syscalls/___fchmodat.S
similarity index 80%
rename from libc/arch-arm64/syscalls/__fchmodat.S
rename to libc/arch-arm64/syscalls/___fchmodat.S
index 2406ea8e3..1ab3736ba 100644
--- a/libc/arch-arm64/syscalls/__fchmodat.S
+++ b/libc/arch-arm64/syscalls/___fchmodat.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(__fchmodat)
+ENTRY(___fchmodat)
mov x8, __NR_fchmodat
svc #0
@@ -11,5 +11,5 @@ ENTRY(__fchmodat)
b.hi __set_errno_internal
ret
-END(__fchmodat)
-.hidden __fchmodat
+END(___fchmodat)
+.hidden ___fchmodat
diff --git a/libc/arch-mips/syscalls/__fchmod.S b/libc/arch-mips/syscalls/___fchmod.S
similarity index 84%
rename from libc/arch-mips/syscalls/__fchmod.S
rename to libc/arch-mips/syscalls/___fchmod.S
index 9bc491c21..ac102ec93 100644
--- a/libc/arch-mips/syscalls/__fchmod.S
+++ b/libc/arch-mips/syscalls/___fchmod.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(__fchmod)
+ENTRY(___fchmod)
.set noreorder
.cpload t9
li v0, __NR_fchmod
@@ -16,4 +16,5 @@ ENTRY(__fchmod)
j t9
nop
.set reorder
-END(__fchmod)
+END(___fchmod)
+.hidden ___fchmod
diff --git a/libc/arch-mips/syscalls/__fchmodat.S b/libc/arch-mips/syscalls/___fchmodat.S
similarity index 82%
rename from libc/arch-mips/syscalls/__fchmodat.S
rename to libc/arch-mips/syscalls/___fchmodat.S
index 07ea8f8b3..d581efa3b 100644
--- a/libc/arch-mips/syscalls/__fchmodat.S
+++ b/libc/arch-mips/syscalls/___fchmodat.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(__fchmodat)
+ENTRY(___fchmodat)
.set noreorder
.cpload t9
li v0, __NR_fchmodat
@@ -16,4 +16,5 @@ ENTRY(__fchmodat)
j t9
nop
.set reorder
-END(__fchmodat)
+END(___fchmodat)
+.hidden ___fchmodat
diff --git a/libc/arch-mips64/syscalls/__fchmod.S b/libc/arch-mips64/syscalls/___fchmod.S
similarity index 87%
rename from libc/arch-mips64/syscalls/__fchmod.S
rename to libc/arch-mips64/syscalls/___fchmod.S
index 94dd0a1e7..7c16c54d1 100644
--- a/libc/arch-mips64/syscalls/__fchmod.S
+++ b/libc/arch-mips64/syscalls/___fchmod.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(__fchmod)
+ENTRY(___fchmod)
.set push
.set noreorder
li v0, __NR_fchmod
@@ -22,5 +22,5 @@ ENTRY(__fchmod)
j t9
move ra, t0
.set pop
-END(__fchmod)
-.hidden __fchmod
+END(___fchmod)
+.hidden ___fchmod
diff --git a/libc/arch-mips64/syscalls/__fchmodat.S b/libc/arch-mips64/syscalls/___fchmodat.S
similarity index 86%
rename from libc/arch-mips64/syscalls/__fchmodat.S
rename to libc/arch-mips64/syscalls/___fchmodat.S
index 79f453f4c..50f108ebf 100644
--- a/libc/arch-mips64/syscalls/__fchmodat.S
+++ b/libc/arch-mips64/syscalls/___fchmodat.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(__fchmodat)
+ENTRY(___fchmodat)
.set push
.set noreorder
li v0, __NR_fchmodat
@@ -22,5 +22,5 @@ ENTRY(__fchmodat)
j t9
move ra, t0
.set pop
-END(__fchmodat)
-.hidden __fchmodat
+END(___fchmodat)
+.hidden ___fchmodat
diff --git a/libc/arch-x86/syscalls/__fchmod.S b/libc/arch-x86/syscalls/___fchmod.S
similarity index 91%
rename from libc/arch-x86/syscalls/__fchmod.S
rename to libc/arch-x86/syscalls/___fchmod.S
index 7ad213e7e..119a69564 100644
--- a/libc/arch-x86/syscalls/__fchmod.S
+++ b/libc/arch-x86/syscalls/___fchmod.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(__fchmod)
+ENTRY(___fchmod)
pushl %ebx
.cfi_def_cfa_offset 8
.cfi_rel_offset ebx, 0
@@ -23,4 +23,5 @@ ENTRY(__fchmod)
popl %ecx
popl %ebx
ret
-END(__fchmod)
+END(___fchmod)
+.hidden ___fchmod
diff --git a/libc/arch-x86/syscalls/__fchmodat.S b/libc/arch-x86/syscalls/___fchmodat.S
similarity index 91%
rename from libc/arch-x86/syscalls/__fchmodat.S
rename to libc/arch-x86/syscalls/___fchmodat.S
index f03c03f41..b15bb6448 100644
--- a/libc/arch-x86/syscalls/__fchmodat.S
+++ b/libc/arch-x86/syscalls/___fchmodat.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(__fchmodat)
+ENTRY(___fchmodat)
pushl %ebx
.cfi_def_cfa_offset 8
.cfi_rel_offset ebx, 0
@@ -28,4 +28,5 @@ ENTRY(__fchmodat)
popl %ecx
popl %ebx
ret
-END(__fchmodat)
+END(___fchmodat)
+.hidden ___fchmodat
diff --git a/libc/arch-x86_64/syscalls/__fchmod.S b/libc/arch-x86_64/syscalls/___fchmod.S
similarity index 83%
rename from libc/arch-x86_64/syscalls/__fchmod.S
rename to libc/arch-x86_64/syscalls/___fchmod.S
index ba75f7487..7bccbefb4 100644
--- a/libc/arch-x86_64/syscalls/__fchmod.S
+++ b/libc/arch-x86_64/syscalls/___fchmod.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(__fchmod)
+ENTRY(___fchmod)
movl $__NR_fchmod, %eax
syscall
cmpq $-MAX_ERRNO, %rax
@@ -12,5 +12,5 @@ ENTRY(__fchmod)
call __set_errno_internal
1:
ret
-END(__fchmod)
-.hidden __fchmod
+END(___fchmod)
+.hidden ___fchmod
diff --git a/libc/arch-x86_64/syscalls/__fchmodat.S b/libc/arch-x86_64/syscalls/___fchmodat.S
similarity index 82%
rename from libc/arch-x86_64/syscalls/__fchmodat.S
rename to libc/arch-x86_64/syscalls/___fchmodat.S
index a8fae9525..483ec7d50 100644
--- a/libc/arch-x86_64/syscalls/__fchmodat.S
+++ b/libc/arch-x86_64/syscalls/___fchmodat.S
@@ -2,7 +2,7 @@
#include <private/bionic_asm.h>
-ENTRY(__fchmodat)
+ENTRY(___fchmodat)
movl $__NR_fchmodat, %eax
syscall
cmpq $-MAX_ERRNO, %rax
@@ -12,5 +12,5 @@ ENTRY(__fchmodat)
call __set_errno_internal
1:
ret
-END(__fchmodat)
-.hidden __fchmodat
+END(___fchmodat)
+.hidden ___fchmodat
diff --git a/libc/bionic/fchmod.cpp b/libc/bionic/fchmod.cpp
index 6e020b6be..ace8c6b47 100644
--- a/libc/bionic/fchmod.cpp
+++ b/libc/bionic/fchmod.cpp
@@ -33,11 +33,11 @@
#include <unistd.h>
#include <stdio.h>
-extern "C" int __fchmod(int, mode_t);
+extern "C" int ___fchmod(int, mode_t);
int fchmod(int fd, mode_t mode) {
int saved_errno = errno;
- int result = __fchmod(fd, mode);
+ int result = ___fchmod(fd, mode);
if ((result == 0) || (errno != EBADF)) {
return result;
diff --git a/libc/bionic/fchmodat.cpp b/libc/bionic/fchmodat.cpp
index c28e15ac7..1f83c4b9b 100644
--- a/libc/bionic/fchmodat.cpp
+++ b/libc/bionic/fchmodat.cpp
@@ -34,7 +34,7 @@
#include "private/ErrnoRestorer.h"
-extern "C" int __fchmodat(int, const char*, mode_t);
+extern "C" int ___fchmodat(int, const char*, mode_t);
int fchmodat(int dirfd, const char* pathname, mode_t mode, int flags) {
if ((flags & ~AT_SYMLINK_NOFOLLOW) != 0) {
@@ -63,5 +63,5 @@ int fchmodat(int dirfd, const char* pathname, mode_t mode, int flags) {
return result;
}
- return __fchmodat(dirfd, pathname, mode);
+ return ___fchmodat(dirfd, pathname, mode);
}
diff --git a/libc/tools/gensyscalls.py b/libc/tools/gensyscalls.py
index 4e240777a..7e11418db 100755
--- a/libc/tools/gensyscalls.py
+++ b/libc/tools/gensyscalls.py
@@ -286,8 +286,9 @@ def add_footer(pointer_length, stub, syscall):
for alias in aliases:
stub += function_alias % { "func" : syscall["func"], "alias" : alias }
- # Use hidden visibility for any functions beginning with underscores.
- if pointer_length == 64 and syscall["func"].startswith("__"):
+ # Use hidden visibility on LP64 for any functions beginning with underscores.
+ # Force hidden visibility for any functions which begin with 3 underscores
+ if (pointer_length == 64 and syscall["func"].startswith("__")) or syscall["func"].startswith("___"):
stub += '.hidden ' + syscall["func"] + '\n'
return stub