pgsql: Rework signal handler infrastructure to pass sender info as argu - Mailing list pgsql-committers
| From | Andrew Dunstan |
|---|---|
| Subject | pgsql: Rework signal handler infrastructure to pass sender info as argu |
| Date | |
| Msg-id | E1wCyYE-001529-2i@gemulon.postgresql.org Whole thread |
| List | pgsql-committers |
Rework signal handler infrastructure to pass sender info as argument. Commit 095c9d4cf06 added errdetail() reporting of the PID and UID of the process that sent a termination signal. However, as noted by Andres Freund, the implementation had architectural problems: 1. wrapper_handler() in pqsignal.c contained SIGTERM-specific logic (setting ProcDieSenderPid/Uid), violating its role as a generic signal dispatch wrapper. 2. Using globals to pass sender info between wrapper_handler and the real handler is unsafe when signals nest on some platforms. 3. The syncrep.c errdetail used psprintf() to conditionally embed text via %s, breaking translatability. Adopt the approach proposed by Andres Freund: introduce a pg_signal_info struct that is passed as an argument to all signal handlers via the SIGNAL_ARGS macro. wrapper_handler populates it from siginfo_t when SA_SIGINFO is available, or with zeros otherwise. This keeps wrapper_handler fully generic and avoids any globals for passing signal metadata. Since pqsigfunc now has a different signature from the system's signal handler type, SIG_IGN and SIG_DFL can no longer be passed directly to pqsignal(). Introduce PG_SIG_IGN and PG_SIG_DFL macros that cast to the new pqsigfunc type, and update all call sites. The legacy pqsignal() in libpq retains its original signature via a local typedef. Only die() reads pg_siginfo today, copying the sender PID/UID into ProcDieSenderPid/Uid for later use by ProcessInterrupts(). Only the first SIGTERM's sender info is recorded. Also fix the syncrep.c translatability issue by using separate ereport calls with complete, independently translatable errdetail strings. Also make the psql TAP test require the DETAIL line on platforms with SA_SIGINFO, rather than making it unconditionally optional. On Windows, pg_signal_info uses uint32_t for pid and uid fields since pid_t/uid_t are not available early enough in the include chain. The Windows signal dispatch in pgwin32_dispatch_queued_signals() passes a zeroed pg_signal_info to handlers. Author: Andres Freund <andres@anarazel.de> Author: Jakub Wartak <jakub.wartak@enterprisedb.com> Reviewed-by: Andrew Dunstan <andrew@dunslane.net> Reviewed-by: Chao Li <li.evan.chao@gmail.com> Discussion: https://postgr.es/m/cwyyryh2veejuxbj5ifzyaejw7jhhqc5mrdeq56xckknsdecn2@6hzfcxde2nm5 Discussion: https://postgr.es/m/jygesyr7mwg7ovdbxpmjvvbi3hccptpkcreqb645h7f56puwbz@hmkkwi3melfe Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/3e2a1496bae628c379ca0a11ef5f5ba666f24ae8 Modified Files -------------- src/backend/bootstrap/bootstrap.c | 8 +-- src/backend/port/win32/signal.c | 14 +++-- src/backend/postmaster/autovacuum.c | 10 +-- src/backend/postmaster/bgworker.c | 14 ++--- src/backend/postmaster/bgwriter.c | 10 +-- src/backend/postmaster/checkpointer.c | 8 +-- src/backend/postmaster/datachecksum_state.c | 2 +- src/backend/postmaster/pgarch.c | 8 +-- src/backend/postmaster/postmaster.c | 12 ++-- src/backend/postmaster/startup.c | 6 +- src/backend/postmaster/syslogger.c | 14 ++--- src/backend/postmaster/walsummarizer.c | 10 +-- src/backend/postmaster/walwriter.c | 10 +-- src/backend/replication/logical/slotsync.c | 6 +- src/backend/replication/syncrep.c | 28 ++++----- src/backend/replication/walreceiver.c | 10 +-- src/backend/replication/walsender.c | 4 +- src/backend/storage/aio/method_worker.c | 6 +- src/backend/storage/file/fd.c | 4 +- src/backend/storage/ipc/waiteventset.c | 2 +- src/backend/tcop/postgres.c | 19 ++++-- src/bin/initdb/initdb.c | 4 +- src/bin/pg_ctl/pg_ctl.c | 2 +- src/bin/pg_dump/parallel.c | 8 +-- src/bin/psql/t/001_basic.pl | 5 +- src/fe_utils/print.c | 4 +- src/include/c.h | 29 ++++++--- src/include/port.h | 3 + src/interfaces/libpq/legacy-pqsignal.c | 8 ++- src/port/pqsignal.c | 96 ++++++++++++++++++++--------- src/test/regress/pg_regress.c | 2 +- src/tools/pgindent/typedefs.list | 1 + 32 files changed, 218 insertions(+), 149 deletions(-)
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