summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat (limited to 'sys-libs/glibc/files/2.7/glibc-2.7-hardened-inittls-nosysenter.patch')
-rw-r--r--sys-libs/glibc/files/2.7/glibc-2.7-hardened-inittls-nosysenter.patch273
1 files changed, 273 insertions, 0 deletions
diff --git a/sys-libs/glibc/files/2.7/glibc-2.7-hardened-inittls-nosysenter.patch b/sys-libs/glibc/files/2.7/glibc-2.7-hardened-inittls-nosysenter.patch
new file mode 100644
index 0000000..ecf57a9
--- /dev/null
+++ b/sys-libs/glibc/files/2.7/glibc-2.7-hardened-inittls-nosysenter.patch
@@ -0,0 +1,273 @@
+When building glibc PIE (which is not something upstream support),
+several modifications are necessary to the glibc build process.
+
+First, any syscalls in PIEs must be of the PIC variant, otherwise
+textrels ensue. Then, any syscalls made before the initialisation
+of the TLS will fail on i386, as the sysenter variant on i386 uses
+the TLS, giving rise to a chicken-and-egg situation. This patch
+defines a PIC syscall variant that doesn't use sysenter, even when the sysenter
+version is normally used, and uses the non-sysenter version for the brk
+syscall that is performed by the TLS initialisation. Further, the TLS
+initialisation is moved in this case prior to the initialisation of
+dl_osversion, as that requires further syscalls.
+
+csu/libc-start.c: Move initial TLS initialization to before the
+initialisation of dl_osversion, when INTERNAL_SYSCALL_NOSYSENTER is defined
+
+csu/libc-tls.c: Use the no-sysenter version of sbrk when
+INTERNAL_SYSCALL_NOSYSENTER is defined.
+
+misc/sbrk.c: Define a no-sysenter version of sbrk, using the no-sysenter
+version of brk - if INTERNAL_SYSCALL_NOSYSENTER is defined.
+
+misc/brk.c: Define a no-sysenter version of brk if
+INTERNAL_SYSCALL_NOSYSENTER is defined.
+
+sysdeps/unix/sysv/linux/i386/sysdep.h: Define INTERNAL_SYSCALL_NOSYSENTER
+Make INTERNAL_SYSCALL always use the PIC variant, even if not SHARED.
+
+Patch by Kevin F. Quinn <kevquinn@gentoo.org>
+
+--- csu/libc-start.c
++++ csu/libc-start.c
+@@ -28,6 +28,7 @@
+ extern int __libc_multiple_libcs;
+
+ #include <tls.h>
++#include <sysdep.h>
+ #ifndef SHARED
+ # include <dl-osinfo.h>
+ extern void __pthread_initialize_minimal (void);
+@@ -129,6 +130,11 @@
+ # endif
+ _dl_aux_init (auxvec);
+ # endif
++# ifdef INTERNAL_SYSCALL_NOSYSENTER
++ /* Do the initial TLS initialization before _dl_osversion,
++ since the latter uses the uname syscall. */
++ __pthread_initialize_minimal ();
++# endif
+ # ifdef DL_SYSDEP_OSCHECK
+ if (!__libc_multiple_libcs)
+ {
+@@ -138,10 +144,12 @@
+ }
+ # endif
+
++# ifndef INTERNAL_SYSCALL_NOSYSENTER
+ /* Initialize the thread library at least a bit since the libgcc
+ functions are using thread functions if these are available and
+ we need to setup errno. */
+ __pthread_initialize_minimal ();
++# endif
+
+ /* Set up the stack checker's canary. */
+ uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard ();
+--- csu/libc-tls.c
++++ csu/libc-tls.c
+@@ -23,6 +23,7 @@
+ #include <unistd.h>
+ #include <stdio.h>
+ #include <sys/param.h>
++#include <sysdep.h>
+
+
+ #ifdef SHARED
+@@ -29,6 +30,9 @@
+ #error makefile bug, this file is for static only
+ #endif
+
++#ifdef INTERNAL_SYSCALL_NOSYSENTER
++extern void *__sbrk_nosysenter (intptr_t __delta);
++#endif
+ extern ElfW(Phdr) *_dl_phdr;
+ extern size_t _dl_phnum;
+
+@@ -141,14 +145,26 @@
+
+ The initialized value of _dl_tls_static_size is provided by dl-open.c
+ to request some surplus that permits dynamic loading of modules with
+- IE-model TLS. */
++ IE-model TLS.
++
++ Where the normal sbrk would use a syscall that needs the TLS (i386)
++ use the special non-sysenter version instead. */
+ #if TLS_TCB_AT_TP
+ tcb_offset = roundup (memsz + GL(dl_tls_static_size), tcbalign);
++# ifdef INTERNAL_SYSCALL_NOSYSENTER
++ tlsblock = __sbrk_nosysenter (tcb_offset + tcbsize + max_align);
++# else
+ tlsblock = __sbrk (tcb_offset + tcbsize + max_align);
++# endif
+ #elif TLS_DTV_AT_TP
+ tcb_offset = roundup (tcbsize, align ?: 1);
++# ifdef INTERNAL_SYSCALL_NOSYSENTER
++ tlsblock = __sbrk_nosysenter (tcb_offset + memsz + max_align
++ + TLS_PRE_TCB_SIZE + GL(dl_tls_static_size));
++# else
+ tlsblock = __sbrk (tcb_offset + memsz + max_align
+ + TLS_PRE_TCB_SIZE + GL(dl_tls_static_size));
++# endif
+ tlsblock += TLS_PRE_TCB_SIZE;
+ #else
+ /* In case a model with a different layout for the TCB and DTV
+--- misc/sbrk.c
++++ misc/sbrk.c
+@@ -18,6 +18,7 @@
+
+ #include <unistd.h>
+ #include <errno.h>
++#include <sysdep.h>
+
+ /* Defined in brk.c. */
+ extern void *__curbrk;
+@@ -29,6 +30,35 @@
+ /* Extend the process's data space by INCREMENT.
+ If INCREMENT is negative, shrink data space by - INCREMENT.
+ Return start of new space allocated, or -1 for errors. */
++#ifdef INTERNAL_SYSCALL_NOSYSENTER
++/* This version is used by csu/libc-tls.c whem initialising the TLS
++ if the SYSENTER version requires the TLS (which it does on i386).
++ Obviously using the TLS before it is initialised is broken. */
++extern int __brk_nosysenter (void *addr);
++void *
++__sbrk_nosysenter (intptr_t increment)
++{
++ void *oldbrk;
++
++ /* If this is not part of the dynamic library or the library is used
++ via dynamic loading in a statically linked program update
++ __curbrk from the kernel's brk value. That way two separate
++ instances of __brk and __sbrk can share the heap, returning
++ interleaved pieces of it. */
++ if (__curbrk == NULL || __libc_multiple_libcs)
++ if (__brk_nosysenter (0) < 0) /* Initialize the break. */
++ return (void *) -1;
++
++ if (increment == 0)
++ return __curbrk;
++
++ oldbrk = __curbrk;
++ if (__brk_nosysenter (oldbrk + increment) < 0)
++ return (void *) -1;
++
++ return oldbrk;
++}
++#endif
+ void *
+ __sbrk (intptr_t increment)
+ {
+--- sysdeps/unix/sysv/linux/i386/brk.c
++++ sysdeps/unix/sysv/linux/i386/brk.c
+@@ -31,6 +31,30 @@
+ linker. */
+ weak_alias (__curbrk, ___brk_addr)
+
++#ifdef INTERNAL_SYSCALL_NOSYSENTER
++/* This version is used by csu/libc-tls.c whem initialising the TLS
++ * if the SYSENTER version requires the TLS (which it does on i386).
++ * Obviously using the TLS before it is initialised is broken. */
++int
++__brk_nosysenter (void *addr)
++{
++ void *__unbounded newbrk;
++
++ INTERNAL_SYSCALL_DECL (err);
++ newbrk = (void *__unbounded) INTERNAL_SYSCALL_NOSYSENTER (brk, err, 1,
++ __ptrvalue (addr));
++
++ __curbrk = newbrk;
++
++ if (newbrk < addr)
++ {
++ __set_errno (ENOMEM);
++ return -1;
++ }
++
++ return 0;
++}
++#endif
+ int
+ __brk (void *addr)
+ {
+--- sysdeps/unix/sysv/linux/i386/sysdep.h
++++ sysdeps/unix/sysv/linux/i386/sysdep.h
+@@ -187,7 +187,7 @@
+ /* The original calling convention for system calls on Linux/i386 is
+ to use int $0x80. */
+ #ifdef I386_USE_SYSENTER
+-# ifdef SHARED
++# if defined SHARED || defined __PIC__
+ # define ENTER_KERNEL call *%gs:SYSINFO_OFFSET
+ # else
+ # define ENTER_KERNEL call *_dl_sysinfo
+@@ -358,7 +358,7 @@
+ possible to use more than four parameters. */
+ #undef INTERNAL_SYSCALL
+ #ifdef I386_USE_SYSENTER
+-# ifdef SHARED
++# if defined SHARED || defined __PIC__
+ # define INTERNAL_SYSCALL(name, err, nr, args...) \
+ ({ \
+ register unsigned int resultvar; \
+@@ -384,6 +384,18 @@
+ : "0" (name), "i" (offsetof (tcbhead_t, sysinfo)) \
+ ASMFMT_##nr(args) : "memory", "cc"); \
+ (int) resultvar; })
++# define INTERNAL_SYSCALL_NOSYSENTER(name, err, nr, args...) \
++ ({ \
++ register unsigned int resultvar; \
++ EXTRAVAR_##nr \
++ asm volatile ( \
++ LOADARGS_NOSYSENTER_##nr \
++ "movl %1, %%eax\n\t" \
++ "int $0x80\n\t" \
++ RESTOREARGS_NOSYSENTER_##nr \
++ : "=a" (resultvar) \
++ : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc"); \
++ (int) resultvar; })
+ # else
+ # define INTERNAL_SYSCALL(name, err, nr, args...) \
+ ({ \
+@@ -447,12 +459,20 @@
+
+ #define LOADARGS_0
+ #ifdef __PIC__
+-# if defined I386_USE_SYSENTER && defined SHARED
++# if defined I386_USE_SYSENTER && ( defined SHARED || defined __PIC__ )
+ # define LOADARGS_1 \
+ "bpushl .L__X'%k3, %k3\n\t"
+ # define LOADARGS_5 \
+ "movl %%ebx, %4\n\t" \
+ "movl %3, %%ebx\n\t"
++# define LOADARGS_NOSYSENTER_1 \
++ "bpushl .L__X'%k2, %k2\n\t"
++# define LOADARGS_NOSYSENTER_2 LOADARGS_NOSYSENTER_1
++# define LOADARGS_NOSYSENTER_3 LOADARGS_3
++# define LOADARGS_NOSYSENTER_4 LOADARGS_3
++# define LOADARGS_NOSYSENTER_5 \
++ "movl %%ebx, %3\n\t" \
++ "movl %2, %%ebx\n\t"
+ # else
+ # define LOADARGS_1 \
+ "bpushl .L__X'%k2, %k2\n\t"
+@@ -474,11 +495,18 @@
+
+ #define RESTOREARGS_0
+ #ifdef __PIC__
+-# if defined I386_USE_SYSENTER && defined SHARED
++# if defined I386_USE_SYSENTER && ( defined SHARED || defined __PIC__ )
+ # define RESTOREARGS_1 \
+ "bpopl .L__X'%k3, %k3\n\t"
+ # define RESTOREARGS_5 \
+ "movl %4, %%ebx"
++# define RESTOREARGS_NOSYSENTER_1 \
++ "bpopl .L__X'%k2, %k2\n\t"
++# define RESTOREARGS_NOSYSENTER_2 RESTOREARGS_NOSYSENTER_1
++# define RESTOREARGS_NOSYSENTER_3 RESTOREARGS_3
++# define RESTOREARGS_NOSYSENTER_4 RESTOREARGS_3
++# define RESTOREARGS_NOSYSENTER_5 \
++ "movl %3, %%ebx"
+ # else
+ # define RESTOREARGS_1 \
+ "bpopl .L__X'%k2, %k2\n\t"