| Summary: | on s390x, externalvar.exp gets libdwfl failures | ||
|---|---|---|---|
| Product: | systemtap | Reporter: | David Smith <dsmith> |
| Component: | translator | Assignee: | Unassigned <systemtap> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | fche |
| Priority: | P2 | ||
| Version: | unspecified | ||
| Target Milestone: | --- | ||
| Host: | s390x | Target: | |
| Build: | Last reconfirmed: | ||
I've retested this with elfutils-0.141 (the original report was against 0.137) and I see the same problem. (In reply to comment #1) > I've retested this with elfutils-0.141 (the original report was against 0.137) > and I see the same problem. Could you try against a systemtap that includes: commit e2d2c7b8ce287c62ca37c9a744341f7f5babd1ca Author: Mark Wielaard <mjw@redhat.com> Date: Thu Jun 24 21:00:56 2010 +0200 Improve dwflpp::emit_address internal error message. * dwflpp.cxx (dwflpp::emit_address): Be more explicit about context and what failed in case of internal error. That should give us a bit better error message about what is going wrong here. (In reply to comment #2) > (In reply to comment #1) > > I've retested this with elfutils-0.141 (the original report was against 0.137) > > and I see the same problem. > > Could you try against a systemtap that includes: > > commit e2d2c7b8ce287c62ca37c9a744341f7f5babd1ca Here you go: Running /root/src/testsuite/systemtap.base/externalvar.exp ... Executing on host: gcc /root/src/testsuite/systemtap.base/externalvar_lib.c -g -O0 -fPIC -shared -lm -o /root/s390x/testsuite/libexternalvar.so (timeout = 300) Executing on host: gcc /root/src/testsuite/systemtap.base/externalvar.c -g -O0 -L/root/s390x/testsuite -lexternalvar -Wl,-rpath,/root/s390x/testsuite -lm -o /root/s390x/testsuite/externalvar (timeout = 300) cmd: stap -d /root/s390x/testsuite/libexternalvar.so -d /root/s390x/testsuite/externalvar -c /root/s390x/testsuite/externalvar /root/src/testsuite/systemtap.base/externalvar.stp cmd output: semantic error: emit_address internal error, dwfl_addrmodule failed, address 0x1a70: identifier '$libvar' at /root/src/testsuite/systemtap.base/externalvar.stp:24:27 source: printf("libvar = %d\n", $libvar); ^ semantic error: emit_address internal error, dwfl_addrmodule failed, address 0x1a68: identifier '$lib_s' at :26:29 source: printf("lib_s->i = %d\n", $lib_s->i); ^ semantic error: emit_address internal error, dwfl_addrmodule failed, address 0x1a68: identifier '$lib_s' at :27:29 source: printf("lib_s->l = %d\n", $lib_s->l); ^ semantic error: emit_address internal error, dwfl_addrmodule failed, address 0x1a68: identifier '$lib_s' at :28:29 source: printf("lib_s->c = %d\n", $lib_s->c); ^ semantic error: emit_address internal error, dwfl_addrmodule failed, address 0x1a68: identifier '$lib_s' at :30:7 source: if ($lib_s == $lib_s->s1) ^ semantic error: emit_address internal error, dwfl_addrmodule failed, address 0x1a68: identifier '$lib_s' at :38:32 source: printf("lib_s->s2 = 0x%x\n", $lib_s->s2); ^ Pass 2: analysis failed. Try again with another '--vp 01' option. FAIL: externalvar line 1: expected "exevar_c = 42", Got "semantic error: emit_address internal error, dwfl_addrmodule failed, address 0x1a70: identifier '$libvar' at /root/src/testsuite/systemtap.base/externalvar.stp:24:27" testcase /root/src/testsuite/systemtap.base/externalvar.exp completed in 0 seconds (In reply to comment #3) > Here you go: > > Running /root/src/testsuite/systemtap.base/externalvar.exp ... > Executing on host: gcc /root/src/testsuite/systemtap.base/externalvar_lib.c -g > -O0 -fPIC -shared -lm -o /root/s390x/testsuite/libexternalvar.so (timeout > = 300) > Executing on host: gcc /root/src/testsuite/systemtap.base/externalvar.c -g -O0 > -L/root/s390x/testsuite -lexternalvar -Wl,-rpath,/root/s390x/testsuite -lm -o > /root/s390x/testsuite/externalvar (timeout = 300) > cmd: stap -d /root/s390x/testsuite/libexternalvar.so -d > /root/s390x/testsuite/externalvar -c /root/s390x/testsuite/externalvar > /root/src/testsuite/systemtap.base/externalvar.stp > cmd output: semantic error: emit_address internal error, dwfl_addrmodule failed, > address 0x1a70: identifier '$libvar' at > /root/src/testsuite/systemtap.base/externalvar.stp:24:27 > source: printf("libvar = %d\n", $libvar); > ^ OK, so this is for all the variables in the library. We think we found, libvar in this case, at address 0x1a70, we try to translate it to a location expression, so we ask libdwfl about it to determine which dwfl module exactly it is in. But then dwfl_addrmodule fails for some reason (but without it setting an error code). Could you try to build the libexternalvar.so as above (or just comment out the rm in the exp file) and see waht loc2c-test says about it? $ ./loc2c-test testsuite/libexternalvar.so 0x1a70 $ ./loc2c-test testsuite/libexternalvar.so 0x1a70 libvar and what does eu-readelf say about the lib_call function? $ eu-readelf -s testsuite/libexternalvar.so | grep lib_call > OK, so this is for all the variables in the library. We think we found, libvar > in this case, at address 0x1a70, we try to translate it to a location > expression, so we ask libdwfl about it to determine which dwfl module exactly it > is in. But then dwfl_addrmodule fails for some reason (but without it setting an > error code). > > Could you try to build the libexternalvar.so as above (or just comment out the > rm in the exp file) and see waht loc2c-test says about it? > > $ ./loc2c-test testsuite/libexternalvar.so 0x1a70 > > $ ./loc2c-test testsuite/libexternalvar.so 0x1a70 libvar After adding '-e', I get: # ./loc2c-test -e testsuite/libexternalvar.so 0x1a70 ./loc2c-test: dwfl_addrdie: address out of range # ./loc2c-test -e testsuite/libexternalvar.so 0x1a70 libvar ./loc2c-test: dwfl_addrdie: address out of range > and what does eu-readelf say about the lib_call function? > > $ eu-readelf -s testsuite/libexternalvar.so | grep lib_call # eu-readelf -s testsuite/libexternalvar.so | grep lib_call 48: 000000000000062c 18 FUNC LOCAL DEFAULT 10 lib_call (In reply to comment #5) > # ./loc2c-test -e testsuite/libexternalvar.so 0x1a70 > ./loc2c-test: dwfl_addrdie: address out of range > # ./loc2c-test -e testsuite/libexternalvar.so 0x1a70 libvar > ./loc2c-test: dwfl_addrdie: address out of range > > > and what does eu-readelf say about the lib_call function? > > > > $ eu-readelf -s testsuite/libexternalvar.so | grep lib_call > > # eu-readelf -s testsuite/libexternalvar.so | grep lib_call > 48: 000000000000062c 18 FUNC LOCAL DEFAULT 10 lib_call thanks. so we "guessed" the address of the lib_call function wrongly. how odd. I assume ./loc2c-test -e testsuite/libexternalvar.so 0x62c libvar does spit out the location information for libvar? Could you run stap -vvvvv -p4 -e 'probe process("testsuite/libexternalvar.so").function("lib_call") { printf("libvar = %d\n", $libvar); }' to see how/what/where we get that 0x1a70 address in the first place? (In reply to comment #6) > > > $ eu-readelf -s testsuite/libexternalvar.so | grep lib_call > > > > # eu-readelf -s testsuite/libexternalvar.so | grep lib_call > > 48: 000000000000062c 18 FUNC LOCAL DEFAULT 10 lib_call > > thanks. so we "guessed" the address of the lib_call function wrongly. how odd. I > assume ./loc2c-test -e testsuite/libexternalvar.so 0x62c libvar does spit out > the location information for libvar? # ./loc2c-test -e testsuite/libexternalvar.so 0x62c libvar #define PROBEADDR 0x62cULL static void print_value(struct pt_regs *regs) { intptr_t value; { uintptr_t addr; { // DWARF expression: 0x3(6768) { uintptr_t s0; s0 = 0x1a70UL; addr = s0; } } { int32_t value = deref (4, addr); value = value; } } /* max expression stack depth 1 */ printk (" ---> %ld\n", (unsigned long) value); return; deref_fault: printk (" => BAD ACCESS\n"); } > Could you run stap -vvvvv -p4 -e 'probe > process("testsuite/libexternalvar.so").function("lib_call") { printf("libvar = > %d\n", $libvar); }' to see how/what/where we get that 0x1a70 address in the > first place? # stap -vvvvv -p4 -e 'probe process("testsuite/libexternalvar.so").function("lib_call") { printf("libvar = %d\n", $libvar); }' SystemTap translator/driver (version 1.2/0.141 non-git sources) Copyright (C) 2005-2010 Red Hat, Inc. and others This is free software; see the source for copying conditions. Session arch: s390 release: 2.6.18-194.el5 Created temporary directory "/tmp/stapwJ00Va" Parsed kernel "/lib/modules/2.6.18-194.el5/build/.config", number of tuples: 744 Parsed kernel "/lib/modules/2.6.18-194.el5/build/Module.symvers", number of vmlinux exports: 2613 Searched "/usr/local/share/systemtap/tapset/s390/*.stp", found 3 Searched "/usr/local/share/systemtap/tapset/*.stp", found 68 Pass 1: parsed user script and 71 library script(s) using 29372virt/20904res/2628shr kb, in 190usr/10sys/204real ms. dwarf_builder::build for /root/s390x/testsuite/libexternalvar.so parsed 'lib_call', func 'lib_call' pattern '/root/s390x/testsuite/libexternalvar.so' matches module '/root/s390x/testsuite/libexternalvar.so' focused on module '/root/s390x/testsuite/libexternalvar.so = [0x10000-0x11a78, bias 0x0] file /root/s390x/testsuite/libexternalvar.so ELF machine s390| (code 22) focused on module '/root/s390x/testsuite/libexternalvar.so' module function cache /root/s390x/testsuite/libexternalvar.so size 2 module function cache /root/s390x/testsuite/libexternalvar.so hit lib_call selected function lib_call function cache /root/s390x/testsuite/libexternalvar.so:/root/src/testsuite/systemtap.base/externalvar_lib.c size 2 function cache /root/s390x/testsuite/libexternalvar.so:/root/src/testsuite/systemtap.base/externalvar_lib.c hit lib_call selected function lib_call prologue searching function 'lib_call' 0x62c-0x63e@/root/src/testsuite/systemtap.base/externalvar_lib.c:28 checking line record 0x62c@/root/src/testsuite/systemtap.base/externalvar_lib.c:28 checking line record 0x636@/root/src/testsuite/systemtap.base/externalvar_lib.c:30 prologue found function 'lib_call' = 0x636 probe lib_call@/root/src/testsuite/systemtap.base/externalvar_lib.c:28 process=/root/s390x/testsuite/libexternalvar.so reloc=.dynamic pc=0x636 entry-pc lookup (dwarf_entrypc dieoffset: 0x17c) = 0x62c (rc 0) finding location for local 'libvar' near address 0x636, module bias 0x10000 get_cfa_ops @0x10636, module_start @0x10000 not found cfa dwarf_builder releasing user dwflpp /root/s390x/testsuite/libexternalvar.so Eliding side-effect-free singleton block operator '{' at <input>:1:67 Resolution problem with probe process("/root/s390x/testsuite/libexternalvar.so").function("lib_call@/root/src/testsuite/systemtap.base/externalvar_lib.c:28") printf("libvar = %d\\n", $libvar) semantic error: emit_address internal error, dwfl_addrmodule failed, address 0x1a70: identifier '$libvar' at <input>:1:93 source: probe process("testsuite/libexternalvar.so").function("lib_call") { printf("libvar = %d\n", $libvar); } ^ Pass 2: analyzed script: 1 probe(s), 0 function(s), 0 embed(s), 0 global(s) using 29912virt/22076res/3304shr kb, in 10usr/0sys/16real ms. Pass 2: analysis failed. Try again with another '--vp 01' option. Running rm -rf /tmp/stapwJ00Va Spawn waitpid result (0x802): 0 Still reproducible with elfutils 0.152, stap 1.6. This is no longer reproducible with elfutils-0.152 and HEAD systemtap (post 2.3). Tested on s390x 2.6.18-348.el5. |
Here's the output of the externalvar.exp testcase on a RHEL5 s390x machine (running with elfutils-0.137-3.el5): Host: Linux ibm-z10-03.rhts.eng.bos.redhat.com 2.6.18-194.el5 #1 SMP Tue Mar 16 22:05:06 EDT 2010 s390x s390x s390x GNU/Linux Snapshot: version 1.2/0.137 non-git sources GCC: 4.1.2 [gcc (GCC) 4.1.2 20080704 (Red Hat 4.1.2-48)] Distro: Red Hat Enterprise Linux Server release 5.5 (Tikanga) Running /root/src/testsuite/systemtap.base/externalvar.exp ... Executing on host: gcc /root/src/testsuite/systemtap.base/externalvar_lib.c -g -O0 -fPIC -shared -lm -o /root/s390x/testsuite/libexternalvar.so (timeout = 300) Executing on host: gcc /root/src/testsuite/systemtap.base/externalvar.c -g -O0 -L/root/s390x/testsuite -lexternalvar -Wl,-rpath,/root/s390x/testsuite -lm -o /root/s390x/testsuite/externalvar (timeout = 300) cmd: stap -d /root/s390x/testsuite/libexternalvar.so -d /root/s390x/testsuite/externalvar -c /root/s390x/testsuite/externalvar /root/src/testsuite/systemtap.base/externalvar.stp cmd output: semantic error: libdwfl failure (dwfl_addrmodule): no error: identifier '$libvar' at /root/src/testsuite/systemtap.base/externalvar.stp:24:27 source: printf("libvar = %d\n", $libvar); ^ semantic error: libdwfl failure (dwfl_addrmodule): no error: identifier '$lib_s' at :26:29 source: printf("lib_s->i = %d\n", $lib_s->i); ^ semantic error: libdwfl failure (dwfl_addrmodule): no error: identifier '$lib_s' at :27:29 source: printf("lib_s->l = %d\n", $lib_s->l); ^ semantic error: libdwfl failure (dwfl_addrmodule): no error: identifier '$lib_s' at :28:29 source: printf("lib_s->c = %d\n", $lib_s->c); ^ semantic error: libdwfl failure (dwfl_addrmodule): no error: identifier '$lib_s' at :30:7 source: if ($lib_s == $lib_s->s1) ^ semantic error: libdwfl failure (dwfl_addrmodule): no error: identifier '$lib_s' at :38:32 source: printf("lib_s->s2 = 0x%x\n", $lib_s->s2); ^ Pass 2: analysis failed. Try again with another '--vp 01' option. FAIL: externalvar line 1: expected "exevar_c = 42", Got "semantic error: libdwfl failure (dwfl_addrmodule): no error: identifier '$libvar' at /root/src/testsuite/systemtap.base/externalvar.stp:24:27" testcase /root/src/testsuite/systemtap.base/externalvar.exp completed in 1 seconds (Note that this testcase doesn't pass on RHEL5 x86_64/ppc64 either, but because systemtap can't find the variables in the shared library during pass 5, not because of libdwfl errors in pass 2.)