* [PATCH 1/2] kallsyms: architecture specific symbol lookups @ 2020-02-28 3:10 Nicholas Piggin 2020-02-28 3:10 ` [PATCH 2/2] powerpc/powernv: Wire up OPAL address lookups Nicholas Piggin 0 siblings, 1 reply; 4+ messages in thread From: Nicholas Piggin @ 2020-02-28 3:10 UTC (permalink / raw) To: linuxppc-dev; +Cc: linux-arch, skiboot, linux-kernel, Nicholas Piggin Provide CONFIG_ARCH_HAS_ADDRESS_LOOKUP which allows architectures to do their own symbol/address lookup if kernel and module lookups miss. powerpc will use this to deal with firmware symbols. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- include/linux/kallsyms.h | 20 ++++++++++++++++++++ kernel/kallsyms.c | 13 ++++++++++++- lib/Kconfig | 3 +++ 3 files changed, 35 insertions(+), 1 deletion(-) diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h index 657a83b943f0..8fdd44873373 100644 --- a/include/linux/kallsyms.h +++ b/include/linux/kallsyms.h @@ -83,6 +83,26 @@ extern int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize, unsigned long *offset); +#ifdef CONFIG_ARCH_HAS_ADDRESS_LOOKUP +const char *arch_address_lookup(unsigned long addr, + unsigned long *symbolsize, + unsigned long *offset, + char **modname, char *namebuf); +unsigned long arch_address_lookup_name(const char *name); +#else +static inline const char *arch_address_lookup(unsigned long addr, + unsigned long *symbolsize, + unsigned long *offset, + char **modname, char *namebuf) +{ + return NULL; +} +static inline unsigned long arch_address_lookup_name(const char *name) +{ + return 0; +} +#endif + /* Lookup an address. modname is set to NULL if it's in the kernel. */ const char *kallsyms_lookup(unsigned long addr, unsigned long *symbolsize, diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index a9b3f660dee7..580c762fadd8 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -164,6 +164,7 @@ static unsigned long kallsyms_sym_address(int idx) unsigned long kallsyms_lookup_name(const char *name) { char namebuf[KSYM_NAME_LEN]; + unsigned long ret; unsigned long i; unsigned int off; @@ -173,7 +174,12 @@ unsigned long kallsyms_lookup_name(const char *name) if (strcmp(namebuf, name) == 0) return kallsyms_sym_address(i); } - return module_kallsyms_lookup_name(name); + + ret = module_kallsyms_lookup_name(name); + if (ret) + return ret; + + return arch_address_lookup_name(name); } EXPORT_SYMBOL_GPL(kallsyms_lookup_name); @@ -311,6 +317,11 @@ const char *kallsyms_lookup(unsigned long addr, if (!ret) ret = ftrace_mod_address_lookup(addr, symbolsize, offset, modname, namebuf); + + if (!ret) + ret = arch_address_lookup(addr, symbolsize, + offset, modname, namebuf); + return ret; } diff --git a/lib/Kconfig b/lib/Kconfig index bc7e56370129..16d3b8dbcadf 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -80,6 +80,9 @@ config ARCH_USE_CMPXCHG_LOCKREF config ARCH_HAS_FAST_MULTIPLIER bool +config ARCH_HAS_ADDRESS_LOOKUP + bool + config INDIRECT_PIO bool "Access I/O in non-MMIO mode" depends on ARM64 -- 2.23.0 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/2] powerpc/powernv: Wire up OPAL address lookups 2020-02-28 3:10 [PATCH 1/2] kallsyms: architecture specific symbol lookups Nicholas Piggin @ 2020-02-28 3:10 ` Nicholas Piggin 2020-03-03 11:43 ` Michael Ellerman 0 siblings, 1 reply; 4+ messages in thread From: Nicholas Piggin @ 2020-02-28 3:10 UTC (permalink / raw) To: linuxppc-dev; +Cc: linux-arch, skiboot, linux-kernel, Nicholas Piggin Use ARCH_HAS_ADDRESS_LOOKUP to look up the opal symbol table. This allows crashes and xmon debugging to print firmware symbols. Oops: System Reset, sig: 6 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc2-dirty #903 NIP: 0000000030020434 LR: 000000003000378c CTR: 0000000030020414 REGS: c0000000fffc3d70 TRAP: 0100 Not tainted (5.6.0-rc2-dirty) MSR: 9000000002101002 <SF,HV,VEC,ME,RI> CR: 28022284 XER: 20040000 CFAR: 0000000030003788 IRQMASK: 3 GPR00: 000000003000378c 0000000031c13c90 0000000030136200 c0000000012cfa10 GPR04: c0000000012cfa10 0000000000000010 0000000000000000 0000000031c10060 GPR08: c0000000012cfaaf 0000000030003640 0000000000000000 0000000000000001 GPR12: 00000000300e0000 c000000001490000 0000000000000000 c00000000139c588 GPR16: 0000000031c10000 c00000000125a900 0000000000000000 c0000000012076a8 GPR20: c0000000012a3950 0000000000000001 0000000031c10060 c0000000012cfaaf GPR24: 0000000000000019 0000000030003640 0000000000000000 0000000000000000 GPR28: 0000000000000010 c0000000012cfa10 0000000000000000 0000000000000000 NIP [0000000030020434] .dummy_console_write_buffer_space+0x20/0x64 [OPAL] LR [000000003000378c] opal_entry+0x14c/0x17c [OPAL] This won't unwind the firmware stack (or its Linux caller) properly if firmware and kernel endians don't match, but that problem could be solved in powerpc's unwinder. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> --- arch/powerpc/Kconfig | 1 + arch/powerpc/include/asm/opal-api.h | 6 +++- arch/powerpc/include/asm/opal.h | 3 ++ arch/powerpc/platforms/powernv/opal-call.c | 2 ++ arch/powerpc/platforms/powernv/opal.c | 40 ++++++++++++++++++++++ 5 files changed, 51 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 497b7d0b2d7e..4d32b02d35e8 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -115,6 +115,7 @@ config PPC # Please keep this list sorted alphabetically. # select ARCH_32BIT_OFF_T if PPC32 + select ARCH_HAS_ADDRESS_LOOKUP if PPC_POWERNV select ARCH_HAS_DEBUG_VIRTUAL select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_ELF_RANDOMIZE diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h index c1f25a760eb1..c3a2a797177a 100644 --- a/arch/powerpc/include/asm/opal-api.h +++ b/arch/powerpc/include/asm/opal-api.h @@ -214,7 +214,11 @@ #define OPAL_SECVAR_GET 176 #define OPAL_SECVAR_GET_NEXT 177 #define OPAL_SECVAR_ENQUEUE_UPDATE 178 -#define OPAL_LAST 178 +#define OPAL_PHB_SET_OPTION 179 +#define OPAL_PHB_GET_OPTION 180 +#define OPAL_GET_SYMBOL 181 +#define OPAL_LOOKUP_SYMBOL 182 +#define OPAL_LAST 182 #define QUIESCE_HOLD 1 /* Spin all calls at entry */ #define QUIESCE_REJECT 2 /* Fail all calls with OPAL_BUSY */ diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h index 9986ac34b8e2..ef2d9273f06f 100644 --- a/arch/powerpc/include/asm/opal.h +++ b/arch/powerpc/include/asm/opal.h @@ -312,6 +312,9 @@ s64 opal_mpipl_query_tag(enum opal_mpipl_tags tag, u64 *addr); s64 opal_signal_system_reset(s32 cpu); s64 opal_quiesce(u64 shutdown_type, s32 cpu); +int64_t opal_get_symbol(uint64_t addr, __be64 *symaddr, __be64 *symsize, char *namebuf, uint64_t buflen); +int64_t opal_lookup_symbol(const char *name, __be64 *symaddr, __be64 *symsize); + /* Internal functions */ extern int early_init_dt_scan_opal(unsigned long node, const char *uname, int depth, void *data); diff --git a/arch/powerpc/platforms/powernv/opal-call.c b/arch/powerpc/platforms/powernv/opal-call.c index 5cd0f52d258f..ba11112d94df 100644 --- a/arch/powerpc/platforms/powernv/opal-call.c +++ b/arch/powerpc/platforms/powernv/opal-call.c @@ -293,3 +293,5 @@ OPAL_CALL(opal_mpipl_query_tag, OPAL_MPIPL_QUERY_TAG); OPAL_CALL(opal_secvar_get, OPAL_SECVAR_GET); OPAL_CALL(opal_secvar_get_next, OPAL_SECVAR_GET_NEXT); OPAL_CALL(opal_secvar_enqueue_update, OPAL_SECVAR_ENQUEUE_UPDATE); +OPAL_CALL(opal_get_symbol, OPAL_GET_SYMBOL); +OPAL_CALL(opal_lookup_symbol, OPAL_LOOKUP_SYMBOL); diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c index 2b3dfd0b6cdd..fdf6c4e6f7f9 100644 --- a/arch/powerpc/platforms/powernv/opal.c +++ b/arch/powerpc/platforms/powernv/opal.c @@ -107,6 +107,46 @@ void opal_configure_cores(void) cur_cpu_spec->cpu_restore(); } +const char *arch_address_lookup(unsigned long addr, + unsigned long *symbolsize, + unsigned long *offset, + char **modname, char *namebuf) +{ + __be64 symaddr; + __be64 symsize; + + if (!firmware_has_feature(FW_FEATURE_OPAL)) + return NULL; + + if (opal_get_symbol(addr, &symaddr, &symsize, namebuf, + cpu_to_be64(KSYM_NAME_LEN)) != OPAL_SUCCESS) + return NULL; + + *symbolsize = be64_to_cpu(symsize); + *offset = addr - be64_to_cpu(symaddr); + *modname = "OPAL"; + + return namebuf; +} + +unsigned long arch_address_lookup_name(const char *name) +{ + __be64 addr; + __be64 size; + + if (!firmware_has_feature(FW_FEATURE_OPAL)) + return 0; + + /* opal: prefix allows lookup of symbols that clash with kernel */ + if (!strncasecmp(name, "opal:", strlen("opal:"))) + name += strlen("opal:"); + + if (opal_lookup_symbol(name, &addr, &size) != OPAL_SUCCESS) + return 0; + + return be64_to_cpu(addr); +} + int __init early_init_dt_scan_opal(unsigned long node, const char *uname, int depth, void *data) { -- 2.23.0 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 2/2] powerpc/powernv: Wire up OPAL address lookups 2020-02-28 3:10 ` [PATCH 2/2] powerpc/powernv: Wire up OPAL address lookups Nicholas Piggin @ 2020-03-03 11:43 ` Michael Ellerman 2020-03-05 3:43 ` Nicholas Piggin 0 siblings, 1 reply; 4+ messages in thread From: Michael Ellerman @ 2020-03-03 11:43 UTC (permalink / raw) To: Nicholas Piggin, linuxppc-dev Cc: linux-arch, skiboot, linux-kernel, Nicholas Piggin Nicholas Piggin <npiggin@gmail.com> writes: > Use ARCH_HAS_ADDRESS_LOOKUP to look up the opal symbol table. This > allows crashes and xmon debugging to print firmware symbols. > > Oops: System Reset, sig: 6 [#1] > LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV > Modules linked in: > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc2-dirty #903 > NIP: 0000000030020434 LR: 000000003000378c CTR: 0000000030020414 > REGS: c0000000fffc3d70 TRAP: 0100 Not tainted (5.6.0-rc2-dirty) > MSR: 9000000002101002 <SF,HV,VEC,ME,RI> CR: 28022284 XER: 20040000 > CFAR: 0000000030003788 IRQMASK: 3 > GPR00: 000000003000378c 0000000031c13c90 0000000030136200 c0000000012cfa10 > GPR04: c0000000012cfa10 0000000000000010 0000000000000000 0000000031c10060 > GPR08: c0000000012cfaaf 0000000030003640 0000000000000000 0000000000000001 > GPR12: 00000000300e0000 c000000001490000 0000000000000000 c00000000139c588 > GPR16: 0000000031c10000 c00000000125a900 0000000000000000 c0000000012076a8 > GPR20: c0000000012a3950 0000000000000001 0000000031c10060 c0000000012cfaaf > GPR24: 0000000000000019 0000000030003640 0000000000000000 0000000000000000 > GPR28: 0000000000000010 c0000000012cfa10 0000000000000000 0000000000000000 > NIP [0000000030020434] .dummy_console_write_buffer_space+0x20/0x64 [OPAL] > LR [000000003000378c] opal_entry+0x14c/0x17c [OPAL] > > This won't unwind the firmware stack (or its Linux caller) properly if > firmware and kernel endians don't match, but that problem could be solved > in powerpc's unwinder. How well does this work if we're tracing opal calls at the time we oops :) Though it looks like that's already fishy because we don't do anything to disable tracing of opal_console_write(). I guess I'm a bit wary of adding numerous further opal calls in the oops path, I'm sure the opal symbol lookup code is bug free, but still. Could we instead suck in the opal symbols early on, and search them in Linux? I suspect you've thought of that and rejected it, but it would be good to document why. cheers > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 497b7d0b2d7e..4d32b02d35e8 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -115,6 +115,7 @@ config PPC > # Please keep this list sorted alphabetically. > # > select ARCH_32BIT_OFF_T if PPC32 > + select ARCH_HAS_ADDRESS_LOOKUP if PPC_POWERNV > select ARCH_HAS_DEBUG_VIRTUAL > select ARCH_HAS_DEVMEM_IS_ALLOWED > select ARCH_HAS_ELF_RANDOMIZE > diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h > index c1f25a760eb1..c3a2a797177a 100644 > --- a/arch/powerpc/include/asm/opal-api.h > +++ b/arch/powerpc/include/asm/opal-api.h > @@ -214,7 +214,11 @@ > #define OPAL_SECVAR_GET 176 > #define OPAL_SECVAR_GET_NEXT 177 > #define OPAL_SECVAR_ENQUEUE_UPDATE 178 > -#define OPAL_LAST 178 > +#define OPAL_PHB_SET_OPTION 179 > +#define OPAL_PHB_GET_OPTION 180 Only pull in the calls you need for this patch. > +#define OPAL_GET_SYMBOL 181 > +#define OPAL_LOOKUP_SYMBOL 182 > +#define OPAL_LAST 182 > > #define QUIESCE_HOLD 1 /* Spin all calls at entry */ > #define QUIESCE_REJECT 2 /* Fail all calls with OPAL_BUSY */ > diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h > index 9986ac34b8e2..ef2d9273f06f 100644 > --- a/arch/powerpc/include/asm/opal.h > +++ b/arch/powerpc/include/asm/opal.h > @@ -312,6 +312,9 @@ s64 opal_mpipl_query_tag(enum opal_mpipl_tags tag, u64 *addr); > s64 opal_signal_system_reset(s32 cpu); > s64 opal_quiesce(u64 shutdown_type, s32 cpu); > > +int64_t opal_get_symbol(uint64_t addr, __be64 *symaddr, __be64 *symsize, char *namebuf, uint64_t buflen); > +int64_t opal_lookup_symbol(const char *name, __be64 *symaddr, __be64 *symsize); > + > /* Internal functions */ > extern int early_init_dt_scan_opal(unsigned long node, const char *uname, > int depth, void *data); > diff --git a/arch/powerpc/platforms/powernv/opal-call.c b/arch/powerpc/platforms/powernv/opal-call.c > index 5cd0f52d258f..ba11112d94df 100644 > --- a/arch/powerpc/platforms/powernv/opal-call.c > +++ b/arch/powerpc/platforms/powernv/opal-call.c > @@ -293,3 +293,5 @@ OPAL_CALL(opal_mpipl_query_tag, OPAL_MPIPL_QUERY_TAG); > OPAL_CALL(opal_secvar_get, OPAL_SECVAR_GET); > OPAL_CALL(opal_secvar_get_next, OPAL_SECVAR_GET_NEXT); > OPAL_CALL(opal_secvar_enqueue_update, OPAL_SECVAR_ENQUEUE_UPDATE); > +OPAL_CALL(opal_get_symbol, OPAL_GET_SYMBOL); > +OPAL_CALL(opal_lookup_symbol, OPAL_LOOKUP_SYMBOL); > diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c > index 2b3dfd0b6cdd..fdf6c4e6f7f9 100644 > --- a/arch/powerpc/platforms/powernv/opal.c > +++ b/arch/powerpc/platforms/powernv/opal.c > @@ -107,6 +107,46 @@ void opal_configure_cores(void) > cur_cpu_spec->cpu_restore(); > } > > +const char *arch_address_lookup(unsigned long addr, > + unsigned long *symbolsize, > + unsigned long *offset, > + char **modname, char *namebuf) > +{ > + __be64 symaddr; > + __be64 symsize; > + > + if (!firmware_has_feature(FW_FEATURE_OPAL)) > + return NULL; > + > + if (opal_get_symbol(addr, &symaddr, &symsize, namebuf, > + cpu_to_be64(KSYM_NAME_LEN)) != OPAL_SUCCESS) > + return NULL; > + > + *symbolsize = be64_to_cpu(symsize); > + *offset = addr - be64_to_cpu(symaddr); > + *modname = "OPAL"; > + > + return namebuf; > +} > + > +unsigned long arch_address_lookup_name(const char *name) > +{ > + __be64 addr; > + __be64 size; > + > + if (!firmware_has_feature(FW_FEATURE_OPAL)) > + return 0; > + > + /* opal: prefix allows lookup of symbols that clash with kernel */ > + if (!strncasecmp(name, "opal:", strlen("opal:"))) > + name += strlen("opal:"); > + > + if (opal_lookup_symbol(name, &addr, &size) != OPAL_SUCCESS) > + return 0; > + > + return be64_to_cpu(addr); > +} > + > int __init early_init_dt_scan_opal(unsigned long node, > const char *uname, int depth, void *data) > { > -- > 2.23.0 ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 2/2] powerpc/powernv: Wire up OPAL address lookups 2020-03-03 11:43 ` Michael Ellerman @ 2020-03-05 3:43 ` Nicholas Piggin 0 siblings, 0 replies; 4+ messages in thread From: Nicholas Piggin @ 2020-03-05 3:43 UTC (permalink / raw) To: linuxppc-dev, Michael Ellerman; +Cc: linux-arch, skiboot, linux-kernel Michael Ellerman's on March 3, 2020 9:43 pm: > Nicholas Piggin <npiggin@gmail.com> writes: >> Use ARCH_HAS_ADDRESS_LOOKUP to look up the opal symbol table. This >> allows crashes and xmon debugging to print firmware symbols. >> >> Oops: System Reset, sig: 6 [#1] >> LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV >> Modules linked in: >> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc2-dirty #903 >> NIP: 0000000030020434 LR: 000000003000378c CTR: 0000000030020414 >> REGS: c0000000fffc3d70 TRAP: 0100 Not tainted (5.6.0-rc2-dirty) >> MSR: 9000000002101002 <SF,HV,VEC,ME,RI> CR: 28022284 XER: 20040000 >> CFAR: 0000000030003788 IRQMASK: 3 >> GPR00: 000000003000378c 0000000031c13c90 0000000030136200 c0000000012cfa10 >> GPR04: c0000000012cfa10 0000000000000010 0000000000000000 0000000031c10060 >> GPR08: c0000000012cfaaf 0000000030003640 0000000000000000 0000000000000001 >> GPR12: 00000000300e0000 c000000001490000 0000000000000000 c00000000139c588 >> GPR16: 0000000031c10000 c00000000125a900 0000000000000000 c0000000012076a8 >> GPR20: c0000000012a3950 0000000000000001 0000000031c10060 c0000000012cfaaf >> GPR24: 0000000000000019 0000000030003640 0000000000000000 0000000000000000 >> GPR28: 0000000000000010 c0000000012cfa10 0000000000000000 0000000000000000 >> NIP [0000000030020434] .dummy_console_write_buffer_space+0x20/0x64 [OPAL] >> LR [000000003000378c] opal_entry+0x14c/0x17c [OPAL] >> >> This won't unwind the firmware stack (or its Linux caller) properly if >> firmware and kernel endians don't match, but that problem could be solved >> in powerpc's unwinder. > > How well does this work if we're tracing opal calls at the time we oops :) > > Though it looks like that's already fishy because we don't do anything > to disable tracing of opal_console_write(). Yeah we don't do perfectly well in this case still. OPAL itself has locks in its console paths and some issues with stack reentrancy. We should do a bit better with cutting out more junk including tracing from crash paths, so this doesn't fundamentally make things harder. > I guess I'm a bit wary of adding numerous further opal calls in the oops > path, I'm sure the opal symbol lookup code is bug free, but still. There's a few, console write, event poll, reboot, and NMI IPI AFAIK, so we have to make the opal call path itself robust (it's getting there). > Could we instead suck in the opal symbols early on, and search them in > Linux? I suspect you've thought of that and rejected it, but it would be > good to document why. We could, I was thinking we might want OPAL to do something special with them like add module annotations [OPAL] vs [HOMER] or whatever, relocate itself after boot if we randomize where it's loaded etc. but perhaps none of those things really prevent the symbols being discovered at boot time. I don't know, it was easier? :) >> diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h >> index c1f25a760eb1..c3a2a797177a 100644 >> --- a/arch/powerpc/include/asm/opal-api.h >> +++ b/arch/powerpc/include/asm/opal-api.h >> @@ -214,7 +214,11 @@ >> #define OPAL_SECVAR_GET 176 >> #define OPAL_SECVAR_GET_NEXT 177 >> #define OPAL_SECVAR_ENQUEUE_UPDATE 178 >> -#define OPAL_LAST 178 >> +#define OPAL_PHB_SET_OPTION 179 >> +#define OPAL_PHB_GET_OPTION 180 > > Only pull in the calls you need for this patch. Ah okay I didn't realise that was the policy, makes sense. Thanks, Nick ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-03-05 3:46 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2020-02-28 3:10 [PATCH 1/2] kallsyms: architecture specific symbol lookups Nicholas Piggin 2020-02-28 3:10 ` [PATCH 2/2] powerpc/powernv: Wire up OPAL address lookups Nicholas Piggin 2020-03-03 11:43 ` Michael Ellerman 2020-03-05 3:43 ` Nicholas Piggin
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