From 74e795b9250610aef6364fb523f0aa839b47e17a Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Mon, 9 Jan 2023 10:41:12 +0100 Subject: [PATCH] [gdb/testsuite] Fix gdb.threads/dlopen-libpthread.exp for upstream glibc, again On an x86_64 laptop running ubuntu 22.04.1 with unity desktop: ... $ echo $XDG_CURRENT_DESKTOP Unity:Unity7:ubuntu ... I have: ... $ echo $LD_PRELOAD libgtk3-nocsd.so.0 ... due to package gtk3-nocsd, a package recommended by unity-session. Consequently, for each exec these dependencies are pulled in, including libpthread.so.0: ... $ lddtree /lib/x86_64-linux-gnu/libgtk3-nocsd.so.0 libgtk3-nocsd.so.0 => /lib/x86_64-linux-gnu/libgtk3-nocsd.so.0 (interpreter => none) libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 ld-linux-x86-64.so.2 => /lib/x86_64-linux-gnu/ld-linux-x86-64.so.2 ... So, while test-case gdb.threads/dlopen-libpthread.exp appears to run ok: ... # of expected passes 12 # of unsupported tests 1 ... with LD_PRELOAD="" we have instead: ... (gdb) PASS: gdb.threads/dlopen-libpthread.exp: continue to breakpoint: notify info sharedlibrary^M From To Syms Read Shared Object Library^M $hex $hex Yes /lib64/ld-linux-x86-64.so.2^M $hex $hex Yes /lib/x86_64-linux-gnu/libc.so.6^M $hex $hex Yes dlopen-libpthread.so^M (gdb) FAIL: gdb.threads/dlopen-libpthread.exp: libpthread.so found ... The problem is that libpthread is expected as dependency of dlopen-libpthread.so, but it's missing: ... $ lddtree dlopen-libpthread.so dlopen-libpthread.so => ./dlopen-libpthread.so (interpreter => none) libc.so.6 => $outputs/gdb.threads/dlopen-libpthread/dlopen-libpthread.so.d/libc.so.6 ld-linux-x86-64.so.2 => /lib/x86_64-linux-gnu/ld-linux-x86-64.so.2 ... due to having glibc 2.35, which has lipthread integrated into glibc. Fix this by: - adding a proc has_dependency - using [has_dependency $exec libpthread.so] as hint that libpthread may be preloaded - using ![has_dependency $shlib libpthread.so] to detect that the libpthread.so dependency is missing. Tested on x86_64-linux, with and without LD_PRELOAD="". --- .../gdb.threads/dlopen-libpthread.exp | 30 +++++++++++++++---- gdb/testsuite/lib/gdb.exp | 17 +++++++++++ 2 files changed, 41 insertions(+), 6 deletions(-) diff --git a/gdb/testsuite/gdb.threads/dlopen-libpthread.exp b/gdb/testsuite/gdb.threads/dlopen-libpthread.exp index 0b325ce622f..8259da3d682 100644 --- a/gdb/testsuite/gdb.threads/dlopen-libpthread.exp +++ b/gdb/testsuite/gdb.threads/dlopen-libpthread.exp @@ -61,16 +61,32 @@ foreach probe_name $probe_names { if { !$have_probe } { untested "no matching probes" + return -1 +} + +# We link the exec without -lpthread, but libpthread.so may already be loaded at main +# due to LD_PRELOAD. +set libpthread_maybe_preloaded 0 +set binfile [standard_output_file $executable] +if { [has_dependency $binfile libpthread\\.so] == 1 } { + set libpthread_maybe_preloaded 1 +} + +# We link the shlib with -lpthread, but since glibc 2.34 libpthread has been +# merged with libc, so libpthread.so may not be a dependency. +set libpthread_missing 0 +if { [has_dependency $binfile libpthread\\.so] == 0 } { + set libpthread_missing 1 } set test "libpthread.so not found" gdb_test_multiple "info sharedlibrary" $test { -re "/libpthread\\.so.*\r\n$gdb_prompt $" { - # With newer glibc, libpthread has been integrated into glibc so we - # can expect it to be already loaded at main. This means we no longer - # excercise the scenario we're trying to trigger, but continue - # nevertheless. - unsupported $test + if { $libpthread_maybe_preloaded } { + unsupported $test + } else { + fail $test + } } -re "/libc\\.so.*\r\n$gdb_prompt $" { pass $test @@ -85,4 +101,6 @@ gdb_breakpoint "notify" # Cannot find new threads: generic error gdb_continue_to_breakpoint "notify" ".* notify-here .*" -gdb_test "info sharedlibrary" {/libpthread\.so.*} "libpthread.so found" +if { !$libpthread_missing } { + gdb_test "info sharedlibrary" {/libpthread\.so.*} "libpthread.so found" +} diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp index c41d4698d66..39dfa67c344 100644 --- a/gdb/testsuite/lib/gdb.exp +++ b/gdb/testsuite/lib/gdb.exp @@ -9355,5 +9355,22 @@ proc decompress_bz2 { bz2 } { return $copy } +# Return 1 if the output of "ldd FILE" contains regexp DEP, 0 if it doesn't, +# and -1 if there was a problem running the command. + +proc has_dependency { file dep } { + set ldd [gdb_find_ldd] + set command "$ldd $file" + set result [remote_exec host $command] + set status [lindex $result 0] + set output [lindex $result 1] + verbose -log "status of $command is $status" + verbose -log "output of $command is $output" + if { $status != 0 || $output == "" } { + return -1 + } + return [regexp $dep $output] +} + # Always load compatibility stuff. load_lib future.exp base-commit: 8ec0b0b5df0ebe28c32900afc7ae8ff22b21f381 -- 2.35.3