| Message ID | 20190614152908.8101-8-adhemerval.zanella@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [01/12] m68k: Remove vDSO support | expand |
Adhemerval Zanella <adhemerval.zanella@linaro.org> writes: > * sysdeps/unix/sysv/linux/powerpc/dl-vdso.h: New file. > * sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c > (get_timebase_freq_fallback): New symbol. > (__get_timebase_freq): Call vDSO as a function pointer instead of > arch-specific macros. > * .../unix/sysv/linux/powerpc/gettimeofday.c (gettimeofday): Use > get_vdso_symbol. It's the first time a see a ChangeLog entry starting with '\t* ...'. Is this really valid? > diff --git a/sysdeps/unix/sysv/linux/powerpc/sysdep.h b/sysdeps/unix/sysv/linux/powerpc/sysdep.h > index 20167615c8..cf967a8c33 100644 > --- a/sysdeps/unix/sysv/linux/powerpc/sysdep.h > +++ b/sysdeps/unix/sysv/linux/powerpc/sysdep.h > @@ -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); }) After applying this patch, rt/cpu-clock1 started to fail with: clock_gettime on reaped PID 26033 clock fffffffffffcd272 => Success clock_getres on reaped PID 26033 clock fffffffffffcd272 => Success Both cases are expecting to receive errno = EINVAL instead of Success. Isn't CR0.SO important? Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/kernel/vdso64/gettimeofday.S#n190 -- Tulio Magno
On 17/06/2019 18:48, Tulio Magno Quites Machado Filho wrote: > Adhemerval Zanella <adhemerval.zanella@linaro.org> writes: > >> * sysdeps/unix/sysv/linux/powerpc/dl-vdso.h: New file. >> * sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c >> (get_timebase_freq_fallback): New symbol. >> (__get_timebase_freq): Call vDSO as a function pointer instead of >> arch-specific macros. >> * .../unix/sysv/linux/powerpc/gettimeofday.c (gettimeofday): Use >> get_vdso_symbol. > > It's the first time a see a ChangeLog entry starting with '\t* ...'. > Is this really valid? > >> diff --git a/sysdeps/unix/sysv/linux/powerpc/sysdep.h b/sysdeps/unix/sysv/linux/powerpc/sysdep.h >> index 20167615c8..cf967a8c33 100644 >> --- a/sysdeps/unix/sysv/linux/powerpc/sysdep.h >> +++ b/sysdeps/unix/sysv/linux/powerpc/sysdep.h >> @@ -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); }) > > After applying this patch, rt/cpu-clock1 started to fail with: > > clock_gettime on reaped PID 26033 clock fffffffffffcd272 => Success > clock_getres on reaped PID 26033 clock fffffffffffcd272 => Success > > Both cases are expecting to receive errno = EINVAL instead of Success. > > Isn't CR0.SO important? > > Reference: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/kernel/vdso64/gettimeofday.S#n190 > In fact we can't really remove the CR0.SO check because the vDSO symbol might itself fallback to a syscall (the case of rt/cpu-clock1 where is check for invalid clockid). The vDSO simplification turned out to be less than I expected, but it is moving towards consolidate the time and gettimeofday. Updated patch below. --- Subject: [PATCH 08/12] powerpc: Simplify vsyscall internal macros This patch simplifies the powerpc internal macros for vDSO calls by: - Removing INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK, used solely on get_timebase_freq. - Adjust INTERNAL_VSYSCALL_CALL_TYPE powerpc32 to follow powerpc64 argument ordering. - Use HAVE_*_VSYSCALL instead of explicit strings. - Make powerpc libc-vdso.h include generic implementation. No semantic change expected, checked on powerpc-linux-gnu-power4, powerpc64-linux-gnu, and powerpc64le-linux-gnu. * sysdeps/unix/sysv/linux/libc-vdso.h (VDSO_IFUNC_RET): Define if not defined. * sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c (__get_timebase_freq): Remove use of INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK. (get_timebase_freq_fallback): New symbol. * sysdeps/unix/sysv/linux/powerpc/gettimeofday.c (time): Use HAVE_GETTIMEOFDAY_VSYSCALL. * sysdeps/unix/sysv/linux/powerpc/time.c (gettimeofday): Use HAVE_TIME_VSYSCALL. * sysdeps/unix/sysv/linux/powerpc/libc-vdso.h: Include generic implementation. * sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h (INTERNAL_VSYSCALL_CALL_TYPE): Make calling convention similar to powerpc64. (INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK): Remove macro. * .../sysv/linux/powerpc/powerpc64/sysdep.h (INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK): Likewise. * sysdeps/unix/sysv/linux/powerpc/sysdep.h (HAVE_GETTIMEOFDAY_VSYSCALL): Define. --- sysdeps/unix/sysv/linux/libc-vdso.h | 7 ++++++ .../sysv/linux/powerpc/get_timebase_freq.c | 24 ++++++++++++------- .../unix/sysv/linux/powerpc/gettimeofday.c | 2 +- sysdeps/unix/sysv/linux/powerpc/libc-vdso.h | 24 ++++++++++--------- .../sysv/linux/powerpc/powerpc32/sysdep.h | 18 ++------------ .../sysv/linux/powerpc/powerpc64/sysdep.h | 19 +-------------- sysdeps/unix/sysv/linux/powerpc/sysdep.h | 1 + sysdeps/unix/sysv/linux/powerpc/time.c | 2 +- 8 files changed, 41 insertions(+), 56 deletions(-) diff --git a/sysdeps/unix/sysv/linux/libc-vdso.h b/sysdeps/unix/sysv/linux/libc-vdso.h index f681868137..199ae9a033 100644 --- a/sysdeps/unix/sysv/linux/libc-vdso.h +++ b/sysdeps/unix/sysv/linux/libc-vdso.h @@ -21,6 +21,13 @@ #define VDSO_SYMBOL(__name) __vdso_##__name +/* Adjust the return IFUNC value from a vDSO symbol accordingly required + architecture ABI. It is used for powerpc64 elfv1 to create a ODP + entry since kernvel vDSO does not provide it. */ +#ifndef VDSO_IFUNC_RET +# define VDSO_IFUNC_RET(__value) (__value) +#endif + #ifdef HAVE_CLOCK_GETTIME_VSYSCALL extern int (*VDSO_SYMBOL(clock_gettime)) (clockid_t, struct timespec *); #endif diff --git a/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c b/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c index 23e7694d87..57eb0e19d9 100644 --- a/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c +++ b/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c @@ -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 +93,20 @@ __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); + PTR_DEMANGLE (vdsop); + if (vdsop == NULL) + return get_timebase_freq_fallback (); + + INTERNAL_SYSCALL_DECL (err); + return INTERNAL_VSYSCALL_CALL_TYPE (vdsop, err, uint64_t, 0); +} weak_alias (__get_timebase_freq, __ppc_get_timebase_freq) diff --git a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c index 6b92e2807b..47859abf7a 100644 --- a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c +++ b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c @@ -58,7 +58,7 @@ __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. */ diff --git a/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h b/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h index 47e925493b..170adcc964 100644 --- a/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h +++ b/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h @@ -22,17 +22,9 @@ #include <sysdep.h> #include <sysdep-vdso.h> -#include_next <libc-vdso.h> - -extern unsigned long long (*VDSO_SYMBOL(get_tbfreq)) (void); -#if defined(__PPC64__) || defined(__powerpc64__) -extern void *VDSO_SYMBOL(sigtramp_rt64); -#else -extern void *VDSO_SYMBOL(sigtramp32); -extern void *VDSO_SYMBOL(sigtramp_rt32); -#endif #if (defined(__PPC64__) || defined(__powerpc64__)) && _CALL_ELF != 2 +# include <dl-machine.h> /* 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. @@ -51,7 +43,7 @@ extern void *VDSO_SYMBOL(sigtramp_rt32); 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) \ +# define VDSO_IFUNC_RET(value) \ ({ \ static Elf64_FuncDesc vdso_opd = { .fd_toc = ~0x0 }; \ vdso_opd.fd_func = (Elf64_Addr)value; \ @@ -59,7 +51,17 @@ extern void *VDSO_SYMBOL(sigtramp_rt32); }) #else -#define VDSO_IFUNC_RET(value) ((void *) (value)) +# define VDSO_IFUNC_RET(value) ((void *) (value)) +#endif + +#include_next <libc-vdso.h> + +extern unsigned long long (*VDSO_SYMBOL(get_tbfreq)) (void); +#if defined(__PPC64__) || defined(__powerpc64__) +extern void *VDSO_SYMBOL(sigtramp_rt64); +#else +extern void *VDSO_SYMBOL(sigtramp32); +extern void *VDSO_SYMBOL(sigtramp_rt32); #endif #endif /* _LIBC_VDSO_H */ diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h b/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h index f459543fcd..703c668a92 100644 --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h @@ -41,7 +41,7 @@ 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...) \ +# define INTERNAL_VSYSCALL_CALL_TYPE(funcptr, err, type, nr, args...) \ ({ \ register void *r0 __asm__ ("r0"); \ register long int r3 __asm__ ("r3"); \ @@ -69,7 +69,7 @@ }) #define INTERNAL_VSYSCALL_CALL(funcptr, err, nr, args...) \ - INTERNAL_VSYSCALL_CALL_TYPE(funcptr, err, nr, long int, args) + INTERNAL_VSYSCALL_CALL_TYPE(funcptr, err, long int, nr, args) # undef INLINE_SYSCALL # define INLINE_SYSCALL(name, nr, args...) \ @@ -131,20 +131,6 @@ # undef INTERNAL_SYSCALL_ERRNO # define INTERNAL_SYSCALL_ERRNO(val, err) (val) -# 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, nr, type, ##args); \ - else \ - err = 1 << 28; \ - sc_ret; \ - }) - # define LOADARGS_0(name, dummy) \ r0 = name # define LOADARGS_1(name, __arg1) \ diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h b/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h index 06222f52e6..e7b2fce05f 100644 --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h @@ -45,22 +45,6 @@ #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 @@ -94,10 +78,9 @@ #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); \ diff --git a/sysdeps/unix/sysv/linux/powerpc/sysdep.h b/sysdeps/unix/sysv/linux/powerpc/sysdep.h index 20167615c8..357d1b5243 100644 --- a/sysdeps/unix/sysv/linux/powerpc/sysdep.h +++ b/sysdeps/unix/sysv/linux/powerpc/sysdep.h @@ -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__) diff --git a/sysdeps/unix/sysv/linux/powerpc/time.c b/sysdeps/unix/sysv/linux/powerpc/time.c index 53fd119b00..4856da0862 100644 --- a/sysdeps/unix/sysv/linux/powerpc/time.c +++ b/sysdeps/unix/sysv/linux/powerpc/time.c @@ -67,7 +67,7 @@ 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, -- 2.17.1
Adhemerval Zanella <adhemerval.zanella@linaro.org> writes: > Subject: [PATCH 08/12] powerpc: Simplify vsyscall internal macros > > This patch simplifies the powerpc internal macros for vDSO calls > by: > > - Removing INTERNAL_VSYSCALL_NO_SYSCALL_FALLBACK, used solely on > get_timebase_freq. > > - Adjust INTERNAL_VSYSCALL_CALL_TYPE powerpc32 to follow powerpc64 > argument ordering. > > - Use HAVE_*_VSYSCALL instead of explicit strings. > > - Make powerpc libc-vdso.h include generic implementation. > > No semantic change expected, checked on powerpc-linux-gnu-power4, > powerpc64-linux-gnu, and powerpc64le-linux-gnu. LGTM. Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com> -- Tulio Magno
diff --git a/sysdeps/unix/sysv/linux/powerpc/dl-vdso.h b/sysdeps/unix/sysv/linux/powerpc/dl-vdso.h new file mode 100644 index 0000000000..f6858f02b2 --- /dev/null +++ b/sysdeps/unix/sysv/linux/powerpc/dl-vdso.h @@ -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 diff --git a/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c b/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c index 23e7694d87..b551412356 100644 --- a/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c +++ b/sysdeps/unix/sysv/linux/powerpc/get_timebase_freq.c @@ -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) diff --git a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c index 6b92e2807b..7a4e3cca0c 100644 --- a/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c +++ b/sysdeps/unix/sysv/linux/powerpc/gettimeofday.c @@ -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) diff --git a/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h b/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h index 47e925493b..c2da7bd7f1 100644 --- a/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h +++ b/sysdeps/unix/sysv/linux/powerpc/libc-vdso.h @@ -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 */ diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h b/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h index f459543fcd..889c6ac117 100644 --- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.h +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/sysdep.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...) \ ({ \ diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h b/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h index 06222f52e6..4e507db00d 100644 --- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h @@ -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); \ diff --git a/sysdeps/unix/sysv/linux/powerpc/sysdep.h b/sysdeps/unix/sysv/linux/powerpc/sysdep.h index 20167615c8..cf967a8c33 100644 --- a/sysdeps/unix/sysv/linux/powerpc/sysdep.h +++ b/sysdeps/unix/sysv/linux/powerpc/sysdep.h @@ -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__ */ diff --git a/sysdeps/unix/sysv/linux/powerpc/time.c b/sysdeps/unix/sysv/linux/powerpc/time.c index 53fd119b00..ca6721cf95 100644 --- a/sysdeps/unix/sysv/linux/powerpc/time.c +++ b/sysdeps/unix/sysv/linux/powerpc/time.c @@ -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)