new file mode 100644
@@ -0,0 +1,69 @@
+/* ELF symbol resolve functions for VDSO objects. PowerPC version.
+ Copyright (C) 2005-2019 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#ifndef _DL_VDSO_POWERPC_H
+#define _DL_VDSO_POWERPC_H 1
+
+#if (defined(__PPC64__) || defined(__powerpc64__)) && _CALL_ELF != 2
+
+# include <dl-machine.h>
+# define get_vdso_symbol __get_vdso_symbol
+# define get_vdso_mangle_symbol __get_vdso_mangle_symbol
+# include_next <dl-vdso.h>
+# undef get_vdso_symbol
+# undef get_vdso_mangle_symbol
+
+/* The correct solution is for _dl_vdso_vsym to return the address of the OPD
+ for the kernel VDSO function. That address would then be stored in the
+ __vdso_* variables and returned as the result of the IFUNC resolver function.
+ Yet, the kernel does not contain any OPD entries for the VDSO functions
+ (incomplete implementation). However, PLT relocations for IFUNCs still expect
+ the address of an OPD to be returned from the IFUNC resolver function (since
+ PLT entries on PPC64 are just copies of OPDs). The solution for now is to
+ create an artificial static OPD for each VDSO function returned by a resolver
+ function. The TOC value is set to a non-zero value to avoid triggering lazy
+ symbol resolution via .glink0/.plt0 for a zero TOC (requires thread-safe PLT
+ sequences) when the dynamic linker isn't prepared for it e.g. RTLD_NOW. None
+ of the kernel VDSO routines use the TOC or AUX values so any non-zero value
+ will work. Note that function pointer comparisons will not use this artificial
+ static OPD since those are resolved via ADDR64 relocations and will point at
+ the non-IFUNC default OPD for the symbol. Lastly, because the IFUNC relocations
+ are processed immediately at startup the resolver functions and this code need
+ not be thread-safe, but if the caller writes to a PLT slot it must do so in a
+ thread-safe manner with all the required barriers. */
+#define get_vdso_symbol(symbol) \
+ ({ \
+ static Elf64_FuncDesc vdso_opd_##symbol = { .fd_toc = ~0x0 }; \
+ vdso_opd_##symbol.fd_func = (Elf64_Addr) __get_vdso_symbol (symbol); \
+ (void*)&vdso_opd_##symbol; \
+ })
+
+#define get_vdso_mangle_symbol(symbol) \
+ ({ \
+ static Elf64_FuncDesc vdso_opd_##symbol = { .fd_toc = ~0x0 }; \
+ vdso_opd_##symbol.fd_func = (Elf64_Addr) __get_vdso_symbol (symbol); \
+ void *vdsop = &vdso_opd_##symbol; \
+ PTR_MANGLE (vdsop); \
+ vdsop; \
+ })
+
+#else
+# include_next <dl-vdso.h>
+#endif
+
+#endif
@@ -23,17 +23,11 @@
#include <not-cancel.h>
#include <libc-vdso.h>
-uint64_t
-__get_timebase_freq (void)
+static uint64_t
+get_timebase_freq_fallback (void)
{
hp_timing_t result = 0L;
-#ifdef SHARED
- /* The vDSO does not return an error (it clear cr0.so on returning). */
- INTERNAL_SYSCALL_DECL (err);
- result =
- INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK (get_tbfreq, err, uint64_t, 0);
-#else
/* We read the information from the /proc filesystem. /proc/cpuinfo
contains at least one line like:
timebase : 33333333
@@ -99,8 +93,18 @@ __get_timebase_freq (void)
}
}
}
-#endif
return result;
}
+
+uint64_t
+__get_timebase_freq (void)
+{
+ /* The vDSO does not have a fallback mechanism (such calling a syscall). */
+ __typeof (VDSO_SYMBOL (get_tbfreq)) vdsop = VDSO_SYMBOL (get_tbfreq);
+ if (vdsop == NULL)
+ return get_timebase_freq_fallback ();
+ PTR_DEMANGLE (vdsop);
+ return vdsop ();
+}
weak_alias (__get_timebase_freq, __ppc_get_timebase_freq)
@@ -58,13 +58,13 @@ __gettimeofday_syscall (struct timeval *tv, struct timezone *tz)
}
# define INIT_ARCH() \
- void *vdso_gettimeofday = get_vdso_symbol ("__kernel_gettimeofday")
+ void *vdso_gettimeofday = get_vdso_symbol (HAVE_GETTIMEOFDAY_VSYSCALL)
/* If the vDSO is not available we fall back syscall. */
libc_ifunc_hidden (__redirect___gettimeofday, __gettimeofday,
vdso_gettimeofday
- ? VDSO_IFUNC_RET (vdso_gettimeofday)
+ ? vdso_gettimeofday
: (void *) __gettimeofday_syscall);
libc_hidden_def (__gettimeofday)
@@ -32,34 +32,4 @@ extern void *VDSO_SYMBOL(sigtramp32);
extern void *VDSO_SYMBOL(sigtramp_rt32);
#endif
-#if (defined(__PPC64__) || defined(__powerpc64__)) && _CALL_ELF != 2
-/* The correct solution is for _dl_vdso_vsym to return the address of the OPD
- for the kernel VDSO function. That address would then be stored in the
- __vdso_* variables and returned as the result of the IFUNC resolver function.
- Yet, the kernel does not contain any OPD entries for the VDSO functions
- (incomplete implementation). However, PLT relocations for IFUNCs still expect
- the address of an OPD to be returned from the IFUNC resolver function (since
- PLT entries on PPC64 are just copies of OPDs). The solution for now is to
- create an artificial static OPD for each VDSO function returned by a resolver
- function. The TOC value is set to a non-zero value to avoid triggering lazy
- symbol resolution via .glink0/.plt0 for a zero TOC (requires thread-safe PLT
- sequences) when the dynamic linker isn't prepared for it e.g. RTLD_NOW. None
- of the kernel VDSO routines use the TOC or AUX values so any non-zero value
- will work. Note that function pointer comparisons will not use this artificial
- static OPD since those are resolved via ADDR64 relocations and will point at
- the non-IFUNC default OPD for the symbol. Lastly, because the IFUNC relocations
- are processed immediately at startup the resolver functions and this code need
- not be thread-safe, but if the caller writes to a PLT slot it must do so in a
- thread-safe manner with all the required barriers. */
-#define VDSO_IFUNC_RET(value) \
- ({ \
- static Elf64_FuncDesc vdso_opd = { .fd_toc = ~0x0 }; \
- vdso_opd.fd_func = (Elf64_Addr)value; \
- &vdso_opd; \
- })
-
-#else
-#define VDSO_IFUNC_RET(value) ((void *) (value))
-#endif
-
#endif /* _LIBC_VDSO_H */
@@ -34,43 +34,6 @@
# include <errno.h>
-/* Define a macro which expands inline into the wrapper code for a VDSO
- call. This use is for internal calls that do not need to handle errors
- normally. It will never touch errno.
- On powerpc a system call basically clobbers the same registers like a
- function call, with the exception of LR (which is needed for the
- "sc; bnslr+" sequence) and CR (where only CR0.SO is clobbered to signal
- an error return status). */
-# define INTERNAL_VSYSCALL_CALL_TYPE(funcptr, err, nr, type, args...) \
- ({ \
- register void *r0 __asm__ ("r0"); \
- register long int r3 __asm__ ("r3"); \
- register long int r4 __asm__ ("r4"); \
- register long int r5 __asm__ ("r5"); \
- register long int r6 __asm__ ("r6"); \
- register long int r7 __asm__ ("r7"); \
- register long int r8 __asm__ ("r8"); \
- register long int r9 __asm__ ("r9"); \
- register long int r10 __asm__ ("r10"); \
- register long int r11 __asm__ ("r11"); \
- register long int r12 __asm__ ("r12"); \
- register type rval __asm__ ("r3"); \
- LOADARGS_##nr (funcptr, args); \
- __asm__ __volatile__ \
- ("mtctr %0\n\t" \
- "bctrl\n\t" \
- "mfcr %0" \
- : "+r" (r0), "+r" (r3), "+r" (r4), "+r" (r5), "+r" (r6), "+r" (r7), \
- "+r" (r8), "+r" (r9), "+r" (r10), "+r" (r11), "+r" (r12) \
- : : "cr0", "ctr", "lr", "memory"); \
- err = (long int) r0; \
- __asm__ __volatile__ ("" : "=r" (rval) : "r" (r3), "r" (r4)); \
- rval; \
- })
-
-#define INTERNAL_VSYSCALL_CALL(funcptr, err, nr, args...) \
- INTERNAL_VSYSCALL_CALL_TYPE(funcptr, err, nr, long int, args)
-
# undef INLINE_SYSCALL
# define INLINE_SYSCALL(name, nr, args...) \
({ \
@@ -45,59 +45,9 @@
#endif /* __ASSEMBLER__ */
-/* This version is for internal uses when there is no desire
- to set errno */
-#define INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK(name, err, type, nr, args...) \
- ({ \
- type sc_ret = ENOSYS; \
- \
- __typeof (__vdso_##name) vdsop = __vdso_##name; \
- PTR_DEMANGLE (vdsop); \
- if (vdsop != NULL) \
- sc_ret = \
- INTERNAL_VSYSCALL_CALL_TYPE (vdsop, err, type, nr, ##args); \
- else \
- err = 1 << 28; \
- sc_ret; \
- })
-
-/* Define a macro which expands inline into the wrapper code for a system
- call. This use is for internal calls that do not need to handle errors
- normally. It will never touch errno. This returns just what the kernel
- gave back in the non-error (CR0.SO cleared) case, otherwise (CR0.SO set)
- the negation of the return value in the kernel gets reverted. */
-
-#define INTERNAL_VSYSCALL_CALL_TYPE(funcptr, err, type, nr, args...) \
- ({ \
- register void *r0 __asm__ ("r0"); \
- register long int r3 __asm__ ("r3"); \
- register long int r4 __asm__ ("r4"); \
- register long int r5 __asm__ ("r5"); \
- register long int r6 __asm__ ("r6"); \
- register long int r7 __asm__ ("r7"); \
- register long int r8 __asm__ ("r8"); \
- register type rval __asm__ ("r3"); \
- LOADARGS_##nr (funcptr, args); \
- __asm__ __volatile__ \
- ("mtctr %0\n\t" \
- "bctrl\n\t" \
- "mfcr %0\n\t" \
- "0:" \
- : "+r" (r0), "+r" (r3), "+r" (r4), "+r" (r5), "+r" (r6), \
- "+r" (r7), "+r" (r8) \
- : : "r9", "r10", "r11", "r12", "cr0", "ctr", "lr", "memory"); \
- err = (long int) r0; \
- __asm__ __volatile__ ("" : "=r" (rval) : "r" (r3)); \
- rval; \
- })
-
-#define INTERNAL_VSYSCALL_CALL(funcptr, err, nr, args...) \
- INTERNAL_VSYSCALL_CALL_TYPE(funcptr, err, long int, nr, args)
-
-#undef INLINE_SYSCALL
-
/* This version is for kernels that implement system calls that
behave like function calls as far as register saving. */
+#undef INLINE_SYSCALL
#define INLINE_SYSCALL(name, nr, args...) \
({ \
INTERNAL_SYSCALL_DECL (sc_err); \
@@ -24,6 +24,7 @@
#define HAVE_CLOCK_GETTIME_VSYSCALL "__kernel_clock_gettime"
#define HAVE_GETCPU_VSYSCALL "__kernel_getcpu"
#define HAVE_TIME_VSYSCALL "__kernel_time"
+#define HAVE_GETTIMEOFDAY_VSYSCALL "__kernel_gettimeofday"
#define HAVE_GET_TBFREQ "__kernel_get_tbfreq"
#if defined(__PPC64__) || defined(__powerpc64__)
@@ -32,3 +33,12 @@
# define HAVE_SIGTRAMP_32 "__kernel_sigtramp32"
# define HAVE_SIGTRAMP_RT32 "__kernel_sigtramp_rt32"
#endif
+
+#ifndef __ASSEMBLER__
+
+/* PowerPC vDSO symbols always succeed, so there is no need to emulate a
+ function call and check for CR0.SO value. */
+#define INTERNAL_VSYSCALL_CALL(funcptr, err, nr, args...) \
+ ({ err = 0; funcptr (args); })
+
+#endif /* __ASSEMBLER__ */
@@ -67,12 +67,12 @@ time_syscall (time_t *t)
}
# define INIT_ARCH() \
- void *vdso_time = get_vdso_symbol ("__kernel_time");
+ void *vdso_time = get_vdso_symbol (HAVE_TIME_VSYSCALL);
/* If the vDSO is not available we fall back to the syscall. */
libc_ifunc_hidden (__redirect_time, time,
vdso_time
- ? VDSO_IFUNC_RET (vdso_time)
+ ? vdso_time
: (void *) time_syscall);
libc_hidden_def (time)