powerpc/vdso: Switch VDSO to generic C implementation.

With the C VDSO, the performance is slightly lower, but it is worth
it as it will ease maintenance and evolution, and also brings clocks
that are not supported with the ASM VDSO.

On an 8xx at 132 MHz, vdsotest with the ASM VDSO:
  gettimeofday:    		  vdso:  828 nsec/call
  clock-getres-realtime-coarse:   vdso:  391 nsec/call
  clock-gettime-realtime-coarse:  vdso:  614 nsec/call
  clock-getres-realtime:    	  vdso:  460 nsec/call
  clock-gettime-realtime:    	  vdso:  876 nsec/call
  clock-getres-monotonic-coarse:  vdso:  399 nsec/call
  clock-gettime-monotonic-coarse: vdso:  691 nsec/call
  clock-getres-monotonic:    	  vdso:  460 nsec/call
  clock-gettime-monotonic:    	  vdso: 1026 nsec/call

On an 8xx at 132 MHz, vdsotest with the C VDSO:
  gettimeofday:    		  vdso:  955 nsec/call
  clock-getres-realtime-coarse:   vdso:  545 nsec/call
  clock-gettime-realtime-coarse:  vdso:  592 nsec/call
  clock-getres-realtime:          vdso:  545 nsec/call
  clock-gettime-realtime:    	  vdso:  941 nsec/call
  clock-getres-monotonic-coarse:  vdso:  545 nsec/call
  clock-gettime-monotonic-coarse: vdso:  591 nsec/call
  clock-getres-monotonic:         vdso:  545 nsec/call
  clock-gettime-monotonic:        vdso:  940 nsec/call

It is even better for gettime with monotonic clocks.

Unsupported clocks with ASM VDSO:
  clock-gettime-boottime:         vdso: 3851 nsec/call
  clock-gettime-tai:      	  vdso: 3852 nsec/call
  clock-gettime-monotonic-raw:    vdso: 3396 nsec/call

Same clocks with C VDSO:
  clock-gettime-tai:              vdso:  941 nsec/call
  clock-gettime-monotonic-raw:    vdso: 1001 nsec/call
  clock-gettime-monotonic-coarse: vdso:  591 nsec/call

On an 8321E at 333 MHz, vdsotest with the ASM VDSO:
  gettimeofday:     		  vdso: 220 nsec/call
  clock-getres-realtime-coarse:   vdso: 102 nsec/call
  clock-gettime-realtime-coarse:  vdso: 178 nsec/call
  clock-getres-realtime:          vdso: 129 nsec/call
  clock-gettime-realtime:    	  vdso: 235 nsec/call
  clock-getres-monotonic-coarse:  vdso: 105 nsec/call
  clock-gettime-monotonic-coarse: vdso: 208 nsec/call
  clock-getres-monotonic:         vdso: 129 nsec/call
  clock-gettime-monotonic:        vdso: 274 nsec/call

On an 8321E at 333 MHz, vdsotest with the C VDSO:
  gettimeofday:    		  vdso: 272 nsec/call
  clock-getres-realtime-coarse:   vdso: 160 nsec/call
  clock-gettime-realtime-coarse:  vdso: 184 nsec/call
  clock-getres-realtime:          vdso: 166 nsec/call
  clock-gettime-realtime:         vdso: 281 nsec/call
  clock-getres-monotonic-coarse:  vdso: 160 nsec/call
  clock-gettime-monotonic-coarse: vdso: 184 nsec/call
  clock-getres-monotonic:         vdso: 169 nsec/call
  clock-gettime-monotonic:        vdso: 275 nsec/call

On a Power9 Nimbus DD2.2 at 3.8GHz, with the ASM VDSO:
  clock-gettime-monotonic:    	  vdso:  35 nsec/call
  clock-getres-monotonic:    	  vdso:  16 nsec/call
  clock-gettime-monotonic-coarse: vdso:  18 nsec/call
  clock-getres-monotonic-coarse:  vdso: 522 nsec/call
  clock-gettime-monotonic-raw:    vdso: 598 nsec/call
  clock-getres-monotonic-raw:     vdso: 520 nsec/call
  clock-gettime-realtime:    	  vdso:  34 nsec/call
  clock-getres-realtime:    	  vdso:  16 nsec/call
  clock-gettime-realtime-coarse:  vdso:  18 nsec/call
  clock-getres-realtime-coarse:   vdso: 517 nsec/call
  getcpu:    			  vdso:   8 nsec/call
  gettimeofday:    		  vdso:  25 nsec/call

And with the C VDSO:
  clock-gettime-monotonic:    	  vdso:  37 nsec/call
  clock-getres-monotonic:    	  vdso:  20 nsec/call
  clock-gettime-monotonic-coarse: vdso:  21 nsec/call
  clock-getres-monotonic-coarse:  vdso:  19 nsec/call
  clock-gettime-monotonic-raw:    vdso:  38 nsec/call
  clock-getres-monotonic-raw:     vdso:  20 nsec/call
  clock-gettime-realtime:    	  vdso:  37 nsec/call
  clock-getres-realtime:    	  vdso:  20 nsec/call
  clock-gettime-realtime-coarse:  vdso:  20 nsec/call
  clock-getres-realtime-coarse:   vdso:  19 nsec/call
  getcpu:    			  vdso:   8 nsec/call
  gettimeofday:    		  vdso:  28 nsec/call

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201126131006.2431205-8-mpe@ellerman.id.au
This commit is contained in:
Christophe Leroy 2020-11-27 00:10:05 +11:00 committed by Michael Ellerman
parent 7fec9f5d41
commit ab037dd87a
12 changed files with 105 additions and 690 deletions

View File

@ -176,6 +176,7 @@ config PPC
select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER
select GENERIC_TIME_VSYSCALL
select GENERIC_GETTIMEOFDAY
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_HUGE_VMAP if PPC_BOOK3S_64 && PPC_RADIX_MMU
select HAVE_ARCH_JUMP_LABEL
@ -206,6 +207,7 @@ config PPC
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER
select HAVE_GCC_PLUGINS if GCC_VERSION >= 50200 # plugin support on gcc <= 5.1 is buggy on PPC
select HAVE_GENERIC_VDSO
select HAVE_HW_BREAKPOINT if PERF_EVENTS && (PPC_BOOK3S || PPC_8xx)
select HAVE_IDE
select HAVE_IOREMAP_PROT

View File

@ -0,0 +1,25 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_POWERPC_VDSO_VSYSCALL_H
#define _ASM_POWERPC_VDSO_VSYSCALL_H
#ifndef __ASSEMBLY__
#include <linux/timekeeper_internal.h>
#include <asm/vdso_datapage.h>
/*
* Update the vDSO data page to keep in sync with kernel timekeeping.
*/
static __always_inline
struct vdso_data *__arch_get_k_vdso_data(void)
{
return vdso_data->data;
}
#define __arch_get_k_vdso_data __arch_get_k_vdso_data
/* The asm-generic header needs to be included after the definitions above */
#include <asm-generic/vdso/vsyscall.h>
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_POWERPC_VDSO_VSYSCALL_H */

View File

@ -36,6 +36,7 @@
#include <linux/unistd.h>
#include <linux/time.h>
#include <vdso/datapage.h>
#define SYSCALL_MAP_SIZE ((NR_syscalls + 31) / 32)
@ -45,7 +46,7 @@
#ifdef CONFIG_PPC64
struct vdso_data {
struct vdso_arch_data {
__u8 eye_catcher[16]; /* Eyecatcher: SYSTEMCFG:PPC64 0x00 */
struct { /* Systemcfg version numbers */
__u32 major; /* Major number 0x10 */
@ -59,13 +60,13 @@ struct vdso_data {
__u32 processor; /* Processor type 0x1C */
__u64 processorCount; /* # of physical processors 0x20 */
__u64 physicalMemorySize; /* Size of real memory(B) 0x28 */
__u64 tb_orig_stamp; /* Timebase at boot 0x30 */
__u64 tb_orig_stamp; /* (NU) Timebase at boot 0x30 */
__u64 tb_ticks_per_sec; /* Timebase tics / sec 0x38 */
__u64 tb_to_xs; /* Inverse of TB to 2^20 0x40 */
__u64 stamp_xsec; /* 0x48 */
__u64 tb_update_count; /* Timebase atomicity ctr 0x50 */
__u32 tz_minuteswest; /* Minutes west of Greenwich 0x58 */
__u32 tz_dsttime; /* Type of dst correction 0x5C */
__u64 tb_to_xs; /* (NU) Inverse of TB to 2^20 0x40 */
__u64 stamp_xsec; /* (NU) 0x48 */
__u64 tb_update_count; /* (NU) Timebase atomicity ctr 0x50 */
__u32 tz_minuteswest; /* (NU) Min. west of Greenwich 0x58 */
__u32 tz_dsttime; /* (NU) Type of dst correction 0x5C */
__u32 dcache_size; /* L1 d-cache size 0x60 */
__u32 dcache_line_size; /* L1 d-cache line size 0x64 */
__u32 icache_size; /* L1 i-cache size 0x68 */
@ -78,14 +79,10 @@ struct vdso_data {
__u32 icache_block_size; /* L1 i-cache block size */
__u32 dcache_log_block_size; /* L1 d-cache log block size */
__u32 icache_log_block_size; /* L1 i-cache log block size */
__u32 stamp_sec_fraction; /* fractional seconds of stamp_xtime */
__s32 wtom_clock_nsec; /* Wall to monotonic clock nsec */
__s64 wtom_clock_sec; /* Wall to monotonic clock sec */
__s64 stamp_xtime_sec; /* xtime secs as at tb_orig_stamp */
__s64 stamp_xtime_nsec; /* xtime nsecs as at tb_orig_stamp */
__u32 hrtimer_res; /* hrtimer resolution */
__u32 syscall_map_64[SYSCALL_MAP_SIZE]; /* map of syscalls */
__u32 syscall_map_32[SYSCALL_MAP_SIZE]; /* map of syscalls */
struct vdso_data data[CS_BASES];
};
#else /* CONFIG_PPC64 */
@ -93,26 +90,15 @@ struct vdso_data {
/*
* And here is the simpler 32 bits version
*/
struct vdso_data {
__u64 tb_orig_stamp; /* Timebase at boot 0x30 */
struct vdso_arch_data {
__u64 tb_ticks_per_sec; /* Timebase tics / sec 0x38 */
__u64 tb_to_xs; /* Inverse of TB to 2^20 0x40 */
__u64 stamp_xsec; /* 0x48 */
__u32 tb_update_count; /* Timebase atomicity ctr 0x50 */
__u32 tz_minuteswest; /* Minutes west of Greenwich 0x58 */
__u32 tz_dsttime; /* Type of dst correction 0x5C */
__s32 wtom_clock_sec; /* Wall to monotonic clock */
__s32 wtom_clock_nsec;
__s32 stamp_xtime_sec; /* xtime seconds as at tb_orig_stamp */
__s32 stamp_xtime_nsec; /* xtime nsecs as at tb_orig_stamp */
__u32 stamp_sec_fraction; /* fractional seconds of stamp_xtime */
__u32 hrtimer_res; /* hrtimer resolution */
__u32 syscall_map_32[SYSCALL_MAP_SIZE]; /* map of syscalls */
struct vdso_data data[CS_BASES];
};
#endif /* CONFIG_PPC64 */
extern struct vdso_data *vdso_data;
extern struct vdso_arch_data *vdso_data;
#else /* __ASSEMBLY__ */

View File

@ -398,47 +398,16 @@ int main(void)
#endif /* ! CONFIG_PPC64 */
/* datapage offsets for use by vdso */
OFFSET(CFG_TB_ORIG_STAMP, vdso_data, tb_orig_stamp);
OFFSET(CFG_TB_TICKS_PER_SEC, vdso_data, tb_ticks_per_sec);
OFFSET(CFG_TB_TO_XS, vdso_data, tb_to_xs);
OFFSET(CFG_TB_UPDATE_COUNT, vdso_data, tb_update_count);
OFFSET(CFG_TZ_MINUTEWEST, vdso_data, tz_minuteswest);
OFFSET(CFG_TZ_DSTTIME, vdso_data, tz_dsttime);
OFFSET(CFG_SYSCALL_MAP32, vdso_data, syscall_map_32);
OFFSET(WTOM_CLOCK_SEC, vdso_data, wtom_clock_sec);
OFFSET(WTOM_CLOCK_NSEC, vdso_data, wtom_clock_nsec);
OFFSET(STAMP_XTIME_SEC, vdso_data, stamp_xtime_sec);
OFFSET(STAMP_XTIME_NSEC, vdso_data, stamp_xtime_nsec);
OFFSET(STAMP_SEC_FRAC, vdso_data, stamp_sec_fraction);
OFFSET(CLOCK_HRTIMER_RES, vdso_data, hrtimer_res);
OFFSET(VDSO_DATA_OFFSET, vdso_arch_data, data);
OFFSET(CFG_TB_TICKS_PER_SEC, vdso_arch_data, tb_ticks_per_sec);
OFFSET(CFG_SYSCALL_MAP32, vdso_arch_data, syscall_map_32);
#ifdef CONFIG_PPC64
OFFSET(CFG_ICACHE_BLOCKSZ, vdso_data, icache_block_size);
OFFSET(CFG_DCACHE_BLOCKSZ, vdso_data, dcache_block_size);
OFFSET(CFG_ICACHE_LOGBLOCKSZ, vdso_data, icache_log_block_size);
OFFSET(CFG_DCACHE_LOGBLOCKSZ, vdso_data, dcache_log_block_size);
OFFSET(CFG_SYSCALL_MAP64, vdso_data, syscall_map_64);
OFFSET(TVAL64_TV_SEC, __kernel_old_timeval, tv_sec);
OFFSET(TVAL64_TV_USEC, __kernel_old_timeval, tv_usec);
OFFSET(CFG_ICACHE_BLOCKSZ, vdso_arch_data, icache_block_size);
OFFSET(CFG_DCACHE_BLOCKSZ, vdso_arch_data, dcache_block_size);
OFFSET(CFG_ICACHE_LOGBLOCKSZ, vdso_arch_data, icache_log_block_size);
OFFSET(CFG_DCACHE_LOGBLOCKSZ, vdso_arch_data, dcache_log_block_size);
OFFSET(CFG_SYSCALL_MAP64, vdso_arch_data, syscall_map_64);
#endif
OFFSET(TSPC64_TV_SEC, __kernel_timespec, tv_sec);
OFFSET(TSPC64_TV_NSEC, __kernel_timespec, tv_nsec);
OFFSET(TVAL32_TV_SEC, old_timeval32, tv_sec);
OFFSET(TVAL32_TV_USEC, old_timeval32, tv_usec);
OFFSET(TSPC32_TV_SEC, old_timespec32, tv_sec);
OFFSET(TSPC32_TV_NSEC, old_timespec32, tv_nsec);
/* timeval/timezone offsets for use by vdso */
OFFSET(TZONE_TZ_MINWEST, timezone, tz_minuteswest);
OFFSET(TZONE_TZ_DSTTIME, timezone, tz_dsttime);
/* Other bits used by the vdso */
DEFINE(CLOCK_REALTIME, CLOCK_REALTIME);
DEFINE(CLOCK_MONOTONIC, CLOCK_MONOTONIC);
DEFINE(CLOCK_REALTIME_COARSE, CLOCK_REALTIME_COARSE);
DEFINE(CLOCK_MONOTONIC_COARSE, CLOCK_MONOTONIC_COARSE);
DEFINE(CLOCK_MAX, CLOCK_TAI);
DEFINE(NSEC_PER_SEC, NSEC_PER_SEC);
DEFINE(EINVAL, EINVAL);
DEFINE(KTIME_LOW_RES, KTIME_LOW_RES);
#ifdef CONFIG_BUG
DEFINE(BUG_ENTRY_SIZE, sizeof(struct bug_entry));

View File

@ -82,6 +82,7 @@ static struct clocksource clocksource_timebase = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.mask = CLOCKSOURCE_MASK(64),
.read = timebase_read,
.vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER,
};
#define DECREMENTER_DEFAULT_MAX 0x7FFFFFFF
@ -831,95 +832,6 @@ static notrace u64 timebase_read(struct clocksource *cs)
return (u64)get_tb();
}
void update_vsyscall(struct timekeeper *tk)
{
struct timespec64 xt;
struct clocksource *clock = tk->tkr_mono.clock;
u32 mult = tk->tkr_mono.mult;
u32 shift = tk->tkr_mono.shift;
u64 cycle_last = tk->tkr_mono.cycle_last;
u64 new_tb_to_xs, new_stamp_xsec;
u64 frac_sec;
if (clock != &clocksource_timebase)
return;
xt.tv_sec = tk->xtime_sec;
xt.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
/* Make userspace gettimeofday spin until we're done. */
++vdso_data->tb_update_count;
smp_mb();
/*
* This computes ((2^20 / 1e9) * mult) >> shift as a
* 0.64 fixed-point fraction.
* The computation in the else clause below won't overflow
* (as long as the timebase frequency is >= 1.049 MHz)
* but loses precision because we lose the low bits of the constant
* in the shift. Note that 19342813113834067 ~= 2^(20+64) / 1e9.
* For a shift of 24 the error is about 0.5e-9, or about 0.5ns
* over a second. (Shift values are usually 22, 23 or 24.)
* For high frequency clocks such as the 512MHz timebase clock
* on POWER[6789], the mult value is small (e.g. 32768000)
* and so we can shift the constant by 16 initially
* (295147905179 ~= 2^(20+64-16) / 1e9) and then do the
* remaining shifts after the multiplication, which gives a
* more accurate result (e.g. with mult = 32768000, shift = 24,
* the error is only about 1.2e-12, or 0.7ns over 10 minutes).
*/
if (mult <= 62500000 && clock->shift >= 16)
new_tb_to_xs = ((u64) mult * 295147905179ULL) >> (clock->shift - 16);
else
new_tb_to_xs = (u64) mult * (19342813113834067ULL >> clock->shift);
/*
* Compute the fractional second in units of 2^-32 seconds.
* The fractional second is tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift
* in nanoseconds, so multiplying that by 2^32 / 1e9 gives
* it in units of 2^-32 seconds.
* We assume shift <= 32 because clocks_calc_mult_shift()
* generates shift values in the range 0 - 32.
*/
frac_sec = tk->tkr_mono.xtime_nsec << (32 - shift);
do_div(frac_sec, NSEC_PER_SEC);
/*
* Work out new stamp_xsec value for any legacy users of systemcfg.
* stamp_xsec is in units of 2^-20 seconds.
*/
new_stamp_xsec = frac_sec >> 12;
new_stamp_xsec += tk->xtime_sec * XSEC_PER_SEC;
/*
* tb_update_count is used to allow the userspace gettimeofday code
* to assure itself that it sees a consistent view of the tb_to_xs and
* stamp_xsec variables. It reads the tb_update_count, then reads
* tb_to_xs and stamp_xsec and then reads tb_update_count again. If
* the two values of tb_update_count match and are even then the
* tb_to_xs and stamp_xsec values are consistent. If not, then it
* loops back and reads them again until this criteria is met.
*/
vdso_data->tb_orig_stamp = cycle_last;
vdso_data->stamp_xsec = new_stamp_xsec;
vdso_data->tb_to_xs = new_tb_to_xs;
vdso_data->wtom_clock_sec = tk->wall_to_monotonic.tv_sec;
vdso_data->wtom_clock_nsec = tk->wall_to_monotonic.tv_nsec;
vdso_data->stamp_xtime_sec = xt.tv_sec;
vdso_data->stamp_xtime_nsec = xt.tv_nsec;
vdso_data->stamp_sec_fraction = frac_sec;
vdso_data->hrtimer_res = hrtimer_resolution;
smp_wmb();
++(vdso_data->tb_update_count);
}
void update_vsyscall_tz(void)
{
vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
vdso_data->tz_dsttime = sys_tz.tz_dsttime;
}
static void __init clocksource_init(void)
{
struct clocksource *clock = &clocksource_timebase;
@ -1079,7 +991,6 @@ void __init time_init(void)
sys_tz.tz_dsttime = 0;
}
vdso_data->tb_update_count = 0;
vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
/* initialise and enable the large decrementer (if we have one) */

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@ -17,6 +17,7 @@
#include <linux/elf.h>
#include <linux/security.h>
#include <linux/memblock.h>
#include <vdso/datapage.h>
#include <asm/processor.h>
#include <asm/mmu.h>
@ -70,10 +71,10 @@ static int vdso_ready;
* with it, it will become dynamically allocated
*/
static union {
struct vdso_data data;
struct vdso_arch_data data;
u8 page[PAGE_SIZE];
} vdso_data_store __page_aligned_data;
struct vdso_data *vdso_data = &vdso_data_store.data;
struct vdso_arch_data *vdso_data = &vdso_data_store.data;
/* Format of the patch table */
struct vdso_patch_def

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@ -2,8 +2,20 @@
# List of files in the vdso, has to be asm only for now
ARCH_REL_TYPE_ABS := R_PPC_JUMP_SLOT|R_PPC_GLOB_DAT|R_PPC_ADDR32|R_PPC_ADDR24|R_PPC_ADDR16|R_PPC_ADDR16_LO|R_PPC_ADDR16_HI|R_PPC_ADDR16_HA|R_PPC_ADDR14|R_PPC_ADDR14_BRTAKEN|R_PPC_ADDR14_BRNTAKEN
include $(srctree)/lib/vdso/Makefile
obj-vdso32 = sigtramp.o gettimeofday.o datapage.o cacheflush.o note.o getcpu.o
ifneq ($(c-gettimeofday-y),)
CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y)
CFLAGS_vgettimeofday.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
CFLAGS_vgettimeofday.o += $(call cc-option, -fno-stack-protector)
CFLAGS_vgettimeofday.o += -DDISABLE_BRANCH_PROFILING
CFLAGS_vgettimeofday.o += -ffreestanding -fasynchronous-unwind-tables
CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE)
endif
# Build rules
ifdef CROSS32_COMPILE
@ -15,6 +27,7 @@ endif
CC32FLAGS :=
ifdef CONFIG_PPC64
CC32FLAGS += -m32
KBUILD_CFLAGS := $(filter-out -mcmodel=medium,$(KBUILD_CFLAGS))
endif
targets := $(obj-vdso32) vdso32.so vdso32.so.dbg
@ -23,6 +36,7 @@ obj-vdso32 := $(addprefix $(obj)/, $(obj-vdso32))
GCOV_PROFILE := n
KCOV_INSTRUMENT := n
UBSAN_SANITIZE := n
KASAN_SANITIZE := n
ccflags-y := -shared -fno-common -fno-builtin -nostdlib \
-Wl,-soname=linux-vdso32.so.1 -Wl,--hash-style=both
@ -36,8 +50,8 @@ CPPFLAGS_vdso32.lds += -P -C -Upowerpc
$(obj)/vdso32_wrapper.o : $(obj)/vdso32.so
# link rule for the .so file, .lds has to be first
$(obj)/vdso32.so.dbg: $(src)/vdso32.lds $(obj-vdso32) FORCE
$(call if_changed,vdso32ld)
$(obj)/vdso32.so.dbg: $(src)/vdso32.lds $(obj-vdso32) $(obj)/vgettimeofday.o FORCE
$(call if_changed,vdso32ld_and_check)
# strip rule for the .so file
$(obj)/%.so: OBJCOPYFLAGS := -S
@ -47,12 +61,16 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE
# assembly rules for the .S files
$(obj-vdso32): %.o: %.S FORCE
$(call if_changed_dep,vdso32as)
$(obj)/vgettimeofday.o: %.o: %.c FORCE
$(call if_changed_dep,vdso32cc)
# actual build commands
quiet_cmd_vdso32ld = VDSO32L $@
cmd_vdso32ld = $(VDSOCC) $(c_flags) $(CC32FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^)
quiet_cmd_vdso32ld_and_check = VDSO32L $@
cmd_vdso32ld_and_check = $(VDSOCC) $(c_flags) $(CC32FLAGS) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^) ; $(cmd_vdso_check)
quiet_cmd_vdso32as = VDSO32A $@
cmd_vdso32as = $(VDSOCC) $(a_flags) $(CC32FLAGS) -c -o $@ $<
quiet_cmd_vdso32cc = VDSO32C $@
cmd_vdso32cc = $(VDSOCC) $(c_flags) $(CC32FLAGS) -c -o $@ $<
# install commands for the unstripped file
quiet_cmd_vdso_install = INSTALL $@

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@ -12,13 +12,7 @@
#include <asm/vdso_datapage.h>
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
/* Offset for the low 32-bit part of a field of long type */
#ifdef CONFIG_PPC64
#define LOPART 4
#else
#define LOPART 0
#endif
#include <asm/vdso/gettimeofday.h>
.text
/*
@ -28,32 +22,7 @@
*
*/
V_FUNCTION_BEGIN(__kernel_gettimeofday)
.cfi_startproc
mflr r12
.cfi_register lr,r12
mr. r10,r3 /* r10 saves tv */
mr r11,r4 /* r11 saves tz */
get_datapage r9, r0
beq 3f
LOAD_REG_IMMEDIATE(r7, 1000000) /* load up USEC_PER_SEC */
bl __do_get_tspec@local /* get sec/usec from tb & kernel */
stw r3,TVAL32_TV_SEC(r10)
stw r4,TVAL32_TV_USEC(r10)
3: cmplwi r11,0 /* check if tz is NULL */
mtlr r12
crclr cr0*4+so
li r3,0
beqlr
lwz r4,CFG_TZ_MINUTEWEST(r9)/* fill tz */
lwz r5,CFG_TZ_DSTTIME(r9)
stw r4,TZONE_TZ_MINWEST(r11)
stw r5,TZONE_TZ_DSTTIME(r11)
blr
.cfi_endproc
cvdso_call __c_kernel_gettimeofday
V_FUNCTION_END(__kernel_gettimeofday)
/*
@ -63,127 +32,7 @@ V_FUNCTION_END(__kernel_gettimeofday)
*
*/
V_FUNCTION_BEGIN(__kernel_clock_gettime)
.cfi_startproc
/* Check for supported clock IDs */
cmpli cr0,r3,CLOCK_REALTIME
cmpli cr1,r3,CLOCK_MONOTONIC
cror cr0*4+eq,cr0*4+eq,cr1*4+eq
cmpli cr5,r3,CLOCK_REALTIME_COARSE
cmpli cr6,r3,CLOCK_MONOTONIC_COARSE
cror cr5*4+eq,cr5*4+eq,cr6*4+eq
cror cr0*4+eq,cr0*4+eq,cr5*4+eq
bne cr0, .Lgettime_fallback
mflr r12 /* r12 saves lr */
.cfi_register lr,r12
mr r11,r4 /* r11 saves tp */
get_datapage r9, r0
LOAD_REG_IMMEDIATE(r7, NSEC_PER_SEC) /* load up NSEC_PER_SEC */
beq cr5, .Lcoarse_clocks
.Lprecise_clocks:
bl __do_get_tspec@local /* get sec/nsec from tb & kernel */
bne cr1, .Lfinish /* not monotonic -> all done */
/*
* CLOCK_MONOTONIC
*/
/* now we must fixup using wall to monotonic. We need to snapshot
* that value and do the counter trick again. Fortunately, we still
* have the counter value in r8 that was returned by __do_get_xsec.
* At this point, r3,r4 contain our sec/nsec values, r5 and r6
* can be used, r7 contains NSEC_PER_SEC.
*/
lwz r5,(WTOM_CLOCK_SEC+LOPART)(r9)
lwz r6,WTOM_CLOCK_NSEC(r9)
/* We now have our offset in r5,r6. We create a fake dependency
* on that value and re-check the counter
*/
or r0,r6,r5
xor r0,r0,r0
add r9,r9,r0
lwz r0,(CFG_TB_UPDATE_COUNT+LOPART)(r9)
cmpl cr0,r8,r0 /* check if updated */
bne- .Lprecise_clocks
b .Lfinish_monotonic
/*
* For coarse clocks we get data directly from the vdso data page, so
* we don't need to call __do_get_tspec, but we still need to do the
* counter trick.
*/
.Lcoarse_clocks:
lwz r8,(CFG_TB_UPDATE_COUNT+LOPART)(r9)
andi. r0,r8,1 /* pending update ? loop */
bne- .Lcoarse_clocks
add r9,r9,r0 /* r0 is already 0 */
/*
* CLOCK_REALTIME_COARSE, below values are needed for MONOTONIC_COARSE
* too
*/
lwz r3,STAMP_XTIME_SEC+LOPART(r9)
lwz r4,STAMP_XTIME_NSEC+LOPART(r9)
bne cr6,1f
/* CLOCK_MONOTONIC_COARSE */
lwz r5,(WTOM_CLOCK_SEC+LOPART)(r9)
lwz r6,WTOM_CLOCK_NSEC(r9)
/* check if counter has updated */
or r0,r6,r5
1: or r0,r0,r3
or r0,r0,r4
xor r0,r0,r0
add r3,r3,r0
lwz r0,CFG_TB_UPDATE_COUNT+LOPART(r9)
cmpl cr0,r0,r8 /* check if updated */
bne- .Lcoarse_clocks
/* Counter has not updated, so continue calculating proper values for
* sec and nsec if monotonic coarse, or just return with the proper
* values for realtime.
*/
bne cr6, .Lfinish
/* Calculate and store result. Note that this mimics the C code,
* which may cause funny results if nsec goes negative... is that
* possible at all ?
*/
.Lfinish_monotonic:
add r3,r3,r5
add r4,r4,r6
cmpw cr0,r4,r7
cmpwi cr1,r4,0
blt 1f
subf r4,r7,r4
addi r3,r3,1
1: bge cr1, .Lfinish
addi r3,r3,-1
add r4,r4,r7
.Lfinish:
stw r3,TSPC32_TV_SEC(r11)
stw r4,TSPC32_TV_NSEC(r11)
mtlr r12
crclr cr0*4+so
li r3,0
blr
/*
* syscall fallback
*/
.Lgettime_fallback:
li r0,__NR_clock_gettime
.cfi_restore lr
sc
blr
.cfi_endproc
cvdso_call __c_kernel_clock_gettime
V_FUNCTION_END(__kernel_clock_gettime)
@ -194,37 +43,7 @@ V_FUNCTION_END(__kernel_clock_gettime)
*
*/
V_FUNCTION_BEGIN(__kernel_clock_getres)
.cfi_startproc
/* Check for supported clock IDs */
cmplwi cr0, r3, CLOCK_MAX
cmpwi cr1, r3, CLOCK_REALTIME_COARSE
cmpwi cr7, r3, CLOCK_MONOTONIC_COARSE
bgt cr0, 99f
LOAD_REG_IMMEDIATE(r5, KTIME_LOW_RES)
beq cr1, 1f
beq cr7, 1f
mflr r12
.cfi_register lr,r12
get_datapage r3, r0
lwz r5, CLOCK_HRTIMER_RES(r3)
mtlr r12
1: li r3,0
cmpli cr0,r4,0
crclr cr0*4+so
beqlr
stw r3,TSPC32_TV_SEC(r4)
stw r5,TSPC32_TV_NSEC(r4)
blr
/*
* syscall fallback
*/
99:
li r0,__NR_clock_getres
sc
blr
.cfi_endproc
cvdso_call __c_kernel_clock_getres
V_FUNCTION_END(__kernel_clock_getres)
@ -235,105 +54,5 @@ V_FUNCTION_END(__kernel_clock_getres)
*
*/
V_FUNCTION_BEGIN(__kernel_time)
.cfi_startproc
mflr r12
.cfi_register lr,r12
mr r11,r3 /* r11 holds t */
get_datapage r9, r0
lwz r3,STAMP_XTIME_SEC+LOPART(r9)
cmplwi r11,0 /* check if t is NULL */
mtlr r12
crclr cr0*4+so
beqlr
stw r3,0(r11) /* store result at *t */
blr
.cfi_endproc
cvdso_call_time __c_kernel_time
V_FUNCTION_END(__kernel_time)
/*
* This is the core of clock_gettime() and gettimeofday(),
* it returns the current time in r3 (seconds) and r4.
* On entry, r7 gives the resolution of r4, either USEC_PER_SEC
* or NSEC_PER_SEC, giving r4 in microseconds or nanoseconds.
* It expects the datapage ptr in r9 and doesn't clobber it.
* It clobbers r0, r5 and r6.
* On return, r8 contains the counter value that can be reused.
* This clobbers cr0 but not any other cr field.
*/
__do_get_tspec:
.cfi_startproc
/* Check for update count & load values. We use the low
* order 32 bits of the update count
*/
1: lwz r8,(CFG_TB_UPDATE_COUNT+LOPART)(r9)
andi. r0,r8,1 /* pending update ? loop */
bne- 1b
xor r0,r8,r8 /* create dependency */
add r9,r9,r0
/* Load orig stamp (offset to TB) */
lwz r5,CFG_TB_ORIG_STAMP(r9)
lwz r6,(CFG_TB_ORIG_STAMP+4)(r9)
/* Get a stable TB value */
2: MFTBU(r3)
MFTBL(r4)
MFTBU(r0)
cmplw cr0,r3,r0
bne- 2b
/* Subtract tb orig stamp and shift left 12 bits.
*/
subfc r4,r6,r4
subfe r0,r5,r3
slwi r0,r0,12
rlwimi. r0,r4,12,20,31
slwi r4,r4,12
/*
* Load scale factor & do multiplication.
* We only use the high 32 bits of the tb_to_xs value.
* Even with a 1GHz timebase clock, the high 32 bits of
* tb_to_xs will be at least 4 million, so the error from
* ignoring the low 32 bits will be no more than 0.25ppm.
* The error will just make the clock run very very slightly
* slow until the next time the kernel updates the VDSO data,
* at which point the clock will catch up to the kernel's value,
* so there is no long-term error accumulation.
*/
lwz r5,CFG_TB_TO_XS(r9) /* load values */
mulhwu r4,r4,r5
li r3,0
beq+ 4f /* skip high part computation if 0 */
mulhwu r3,r0,r5
mullw r5,r0,r5
addc r4,r4,r5
addze r3,r3
4:
/* At this point, we have seconds since the xtime stamp
* as a 32.32 fixed-point number in r3 and r4.
* Load & add the xtime stamp.
*/
lwz r5,STAMP_XTIME_SEC+LOPART(r9)
lwz r6,STAMP_SEC_FRAC(r9)
addc r4,r4,r6
adde r3,r3,r5
/* We create a fake dependency on the result in r3/r4
* and re-check the counter
*/
or r6,r4,r3
xor r0,r6,r6
add r9,r9,r0
lwz r0,(CFG_TB_UPDATE_COUNT+LOPART)(r9)
cmplw cr0,r8,r0 /* check if updated */
bne- 1b
mulhwu r4,r4,r7 /* convert to micro or nanoseconds */
blr
.cfi_endproc

View File

@ -111,6 +111,7 @@ SECTIONS
*(.note.GNU-stack)
*(.data .data.* .gnu.linkonce.d.* .sdata*)
*(.bss .sbss .dynbss .dynsbss)
*(.got1)
}
}

View File

@ -1,8 +1,20 @@
# SPDX-License-Identifier: GPL-2.0
# List of files in the vdso, has to be asm only for now
ARCH_REL_TYPE_ABS := R_PPC_JUMP_SLOT|R_PPC_GLOB_DAT|R_PPC_ADDR32|R_PPC_ADDR24|R_PPC_ADDR16|R_PPC_ADDR16_LO|R_PPC_ADDR16_HI|R_PPC_ADDR16_HA|R_PPC_ADDR14|R_PPC_ADDR14_BRTAKEN|R_PPC_ADDR14_BRNTAKEN
include $(srctree)/lib/vdso/Makefile
obj-vdso64 = sigtramp.o gettimeofday.o datapage.o cacheflush.o note.o getcpu.o
ifneq ($(c-gettimeofday-y),)
CFLAGS_vgettimeofday.o += -include $(c-gettimeofday-y)
CFLAGS_vgettimeofday.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
CFLAGS_vgettimeofday.o += $(call cc-option, -fno-stack-protector)
CFLAGS_vgettimeofday.o += -DDISABLE_BRANCH_PROFILING
CFLAGS_vgettimeofday.o += -ffreestanding -fasynchronous-unwind-tables
CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE)
endif
# Build rules
targets := $(obj-vdso64) vdso64.so vdso64.so.dbg
@ -11,6 +23,7 @@ obj-vdso64 := $(addprefix $(obj)/, $(obj-vdso64))
GCOV_PROFILE := n
KCOV_INSTRUMENT := n
UBSAN_SANITIZE := n
KASAN_SANITIZE := n
ccflags-y := -shared -fno-common -fno-builtin -nostdlib \
-Wl,-soname=linux-vdso64.so.1 -Wl,--hash-style=both
@ -20,12 +33,14 @@ obj-y += vdso64_wrapper.o
targets += vdso64.lds
CPPFLAGS_vdso64.lds += -P -C -U$(ARCH)
$(obj)/vgettimeofday.o: %.o: %.c FORCE
# Force dependency (incbin is bad)
$(obj)/vdso64_wrapper.o : $(obj)/vdso64.so
# link rule for the .so file, .lds has to be first
$(obj)/vdso64.so.dbg: $(src)/vdso64.lds $(obj-vdso64) FORCE
$(call if_changed,vdso64ld)
$(obj)/vdso64.so.dbg: $(src)/vdso64.lds $(obj-vdso64) $(obj)/vgettimeofday.o FORCE
$(call if_changed,vdso64ld_and_check)
# strip rule for the .so file
$(obj)/%.so: OBJCOPYFLAGS := -S
@ -33,8 +48,8 @@ $(obj)/%.so: $(obj)/%.so.dbg FORCE
$(call if_changed,objcopy)
# actual build commands
quiet_cmd_vdso64ld = VDSO64L $@
cmd_vdso64ld = $(CC) $(c_flags) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^)
quiet_cmd_vdso64ld_and_check = VDSO64L $@
cmd_vdso64ld_and_check = $(CC) $(c_flags) -o $@ -Wl,-T$(filter %.lds,$^) $(filter %.o,$^); $(cmd_vdso_check)
# install commands for the unstripped file
quiet_cmd_vdso_install = INSTALL $@

View File

@ -12,6 +12,7 @@
#include <asm/vdso_datapage.h>
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
#include <asm/vdso/gettimeofday.h>
.text
/*
@ -21,31 +22,7 @@
*
*/
V_FUNCTION_BEGIN(__kernel_gettimeofday)
.cfi_startproc
mflr r12
.cfi_register lr,r12
mr r11,r3 /* r11 holds tv */
mr r10,r4 /* r10 holds tz */
get_datapage r3, r0
cmpldi r11,0 /* check if tv is NULL */
beq 2f
lis r7,1000000@ha /* load up USEC_PER_SEC */
addi r7,r7,1000000@l
bl V_LOCAL_FUNC(__do_get_tspec) /* get sec/us from tb & kernel */
std r4,TVAL64_TV_SEC(r11) /* store sec in tv */
std r5,TVAL64_TV_USEC(r11) /* store usec in tv */
2: cmpldi r10,0 /* check if tz is NULL */
beq 1f
lwz r4,CFG_TZ_MINUTEWEST(r3)/* fill tz */
lwz r5,CFG_TZ_DSTTIME(r3)
stw r4,TZONE_TZ_MINWEST(r10)
stw r5,TZONE_TZ_DSTTIME(r10)
1: mtlr r12
crclr cr0*4+so
li r3,0 /* always success */
blr
.cfi_endproc
cvdso_call __c_kernel_gettimeofday
V_FUNCTION_END(__kernel_gettimeofday)
@ -56,120 +33,7 @@ V_FUNCTION_END(__kernel_gettimeofday)
*
*/
V_FUNCTION_BEGIN(__kernel_clock_gettime)
.cfi_startproc
/* Check for supported clock IDs */
cmpwi cr0,r3,CLOCK_REALTIME
cmpwi cr1,r3,CLOCK_MONOTONIC
cror cr0*4+eq,cr0*4+eq,cr1*4+eq
cmpwi cr5,r3,CLOCK_REALTIME_COARSE
cmpwi cr6,r3,CLOCK_MONOTONIC_COARSE
cror cr5*4+eq,cr5*4+eq,cr6*4+eq
cror cr0*4+eq,cr0*4+eq,cr5*4+eq
bne cr0,99f
mflr r12 /* r12 saves lr */
.cfi_register lr,r12
mr r11,r4 /* r11 saves tp */
get_datapage r3, r0
lis r7,NSEC_PER_SEC@h /* want nanoseconds */
ori r7,r7,NSEC_PER_SEC@l
beq cr5,70f
50: bl V_LOCAL_FUNC(__do_get_tspec) /* get time from tb & kernel */
bne cr1,80f /* if not monotonic, all done */
/*
* CLOCK_MONOTONIC
*/
/* now we must fixup using wall to monotonic. We need to snapshot
* that value and do the counter trick again. Fortunately, we still
* have the counter value in r8 that was returned by __do_get_tspec.
* At this point, r4,r5 contain our sec/nsec values.
*/
ld r6,WTOM_CLOCK_SEC(r3)
lwa r9,WTOM_CLOCK_NSEC(r3)
/* We now have our result in r6,r9. We create a fake dependency
* on that result and re-check the counter
*/
or r0,r6,r9
xor r0,r0,r0
add r3,r3,r0
ld r0,CFG_TB_UPDATE_COUNT(r3)
cmpld cr0,r0,r8 /* check if updated */
bne- 50b
b 78f
/*
* For coarse clocks we get data directly from the vdso data page, so
* we don't need to call __do_get_tspec, but we still need to do the
* counter trick.
*/
70: ld r8,CFG_TB_UPDATE_COUNT(r3)
andi. r0,r8,1 /* pending update ? loop */
bne- 70b
add r3,r3,r0 /* r0 is already 0 */
/*
* CLOCK_REALTIME_COARSE, below values are needed for MONOTONIC_COARSE
* too
*/
ld r4,STAMP_XTIME_SEC(r3)
ld r5,STAMP_XTIME_NSEC(r3)
bne cr6,75f
/* CLOCK_MONOTONIC_COARSE */
ld r6,WTOM_CLOCK_SEC(r3)
lwa r9,WTOM_CLOCK_NSEC(r3)
/* check if counter has updated */
or r0,r6,r9
75: or r0,r0,r4
or r0,r0,r5
xor r0,r0,r0
add r3,r3,r0
ld r0,CFG_TB_UPDATE_COUNT(r3)
cmpld cr0,r0,r8 /* check if updated */
bne- 70b
/* Counter has not updated, so continue calculating proper values for
* sec and nsec if monotonic coarse, or just return with the proper
* values for realtime.
*/
bne cr6,80f
/* Add wall->monotonic offset and check for overflow or underflow */
78: add r4,r4,r6
add r5,r5,r9
cmpd cr0,r5,r7
cmpdi cr1,r5,0
blt 79f
subf r5,r7,r5
addi r4,r4,1
79: bge cr1,80f
addi r4,r4,-1
add r5,r5,r7
80: std r4,TSPC64_TV_SEC(r11)
std r5,TSPC64_TV_NSEC(r11)
mtlr r12
crclr cr0*4+so
li r3,0
blr
/*
* syscall fallback
*/
99:
li r0,__NR_clock_gettime
.cfi_restore lr
sc
blr
.cfi_endproc
cvdso_call __c_kernel_clock_gettime
V_FUNCTION_END(__kernel_clock_gettime)
@ -180,34 +44,7 @@ V_FUNCTION_END(__kernel_clock_gettime)
*
*/
V_FUNCTION_BEGIN(__kernel_clock_getres)
.cfi_startproc
/* Check for supported clock IDs */
cmpwi cr0,r3,CLOCK_REALTIME
cmpwi cr1,r3,CLOCK_MONOTONIC
cror cr0*4+eq,cr0*4+eq,cr1*4+eq
bne cr0,99f
mflr r12
.cfi_register lr,r12
get_datapage r3, r0
lwz r5, CLOCK_HRTIMER_RES(r3)
mtlr r12
li r3,0
cmpldi cr0,r4,0
crclr cr0*4+so
beqlr
std r3,TSPC64_TV_SEC(r4)
std r5,TSPC64_TV_NSEC(r4)
blr
/*
* syscall fallback
*/
99:
li r0,__NR_clock_getres
sc
blr
.cfi_endproc
cvdso_call __c_kernel_clock_getres
V_FUNCTION_END(__kernel_clock_getres)
/*
@ -217,74 +54,5 @@ V_FUNCTION_END(__kernel_clock_getres)
*
*/
V_FUNCTION_BEGIN(__kernel_time)
.cfi_startproc
mflr r12
.cfi_register lr,r12
mr r11,r3 /* r11 holds t */
get_datapage r3, r0
ld r4,STAMP_XTIME_SEC(r3)
cmpldi r11,0 /* check if t is NULL */
beq 2f
std r4,0(r11) /* store result at *t */
2: mtlr r12
crclr cr0*4+so
mr r3,r4
blr
.cfi_endproc
cvdso_call_time __c_kernel_time
V_FUNCTION_END(__kernel_time)
/*
* This is the core of clock_gettime() and gettimeofday(),
* it returns the current time in r4 (seconds) and r5.
* On entry, r7 gives the resolution of r5, either USEC_PER_SEC
* or NSEC_PER_SEC, giving r5 in microseconds or nanoseconds.
* It expects the datapage ptr in r3 and doesn't clobber it.
* It clobbers r0, r6 and r9.
* On return, r8 contains the counter value that can be reused.
* This clobbers cr0 but not any other cr field.
*/
V_FUNCTION_BEGIN(__do_get_tspec)
.cfi_startproc
/* check for update count & load values */
1: ld r8,CFG_TB_UPDATE_COUNT(r3)
andi. r0,r8,1 /* pending update ? loop */
bne- 1b
xor r0,r8,r8 /* create dependency */
add r3,r3,r0
/* Get TB & offset it. We use the MFTB macro which will generate
* workaround code for Cell.
*/
MFTB(r6)
ld r9,CFG_TB_ORIG_STAMP(r3)
subf r6,r9,r6
/* Scale result */
ld r5,CFG_TB_TO_XS(r3)
sldi r6,r6,12 /* compute time since stamp_xtime */
mulhdu r6,r6,r5 /* in units of 2^-32 seconds */
/* Add stamp since epoch */
ld r4,STAMP_XTIME_SEC(r3)
lwz r5,STAMP_SEC_FRAC(r3)
or r0,r4,r5
or r0,r0,r6
xor r0,r0,r0
add r3,r3,r0
ld r0,CFG_TB_UPDATE_COUNT(r3)
cmpld r0,r8 /* check if updated */
bne- 1b /* reload if so */
/* convert to seconds & nanoseconds and add to stamp */
add r6,r6,r5 /* add on fractional seconds of xtime */
mulhwu r5,r6,r7 /* compute micro or nanoseconds and */
srdi r6,r6,32 /* seconds since stamp_xtime */
clrldi r5,r5,32
add r4,r4,r6
blr
.cfi_endproc
V_FUNCTION_END(__do_get_tspec)

View File

@ -61,7 +61,6 @@ SECTIONS
.gcc_except_table : { *(.gcc_except_table) }
.rela.dyn ALIGN(8) : { *(.rela.dyn) }
.opd ALIGN(8) : { KEEP (*(.opd)) }
.got ALIGN(8) : { *(.got .toc) }
_end = .;
@ -111,6 +110,7 @@ SECTIONS
*(.branch_lt)
*(.data .data.* .gnu.linkonce.d.* .sdata*)
*(.bss .sbss .dynbss .dynsbss)
*(.opd)
}
}