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https://github.com/git/git
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7559a1be8a
Blocked and ignored signals -- but not caught signals -- are inherited across exec. Some callers with sloppy signal-handling behavior can call git with SIGPIPE blocked or ignored, even non-deterministically. When SIGPIPE is blocked or ignored, several git commands can run indefinitely, ignoring EPIPE returns from write() calls, even when the process that called them has gone away. Our specific case involved a pipe of git diff-tree output to a script that reads a limited amount of diff data. In an ideal world, git would never be called with SIGPIPE blocked or ignored. But in the real world, several real potential callers, including Perl, Apache, and Unicorn, sometimes spawn subprocesses with SIGPIPE ignored. It is easier and more productive to harden git against this mistake than to clean it up in every potential parent process. Signed-off-by: Patrick Reynolds <patrick.reynolds@github.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
53 lines
1 KiB
Bash
Executable file
53 lines
1 KiB
Bash
Executable file
#!/bin/sh
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test_description='signals work as we expect'
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. ./test-lib.sh
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cat >expect <<EOF
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three
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two
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one
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EOF
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test_expect_success 'sigchain works' '
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test-sigchain >actual
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case "$?" in
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143) true ;; # POSIX w/ SIGTERM=15
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271) true ;; # ksh w/ SIGTERM=15
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3) true ;; # Windows
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*) false ;;
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esac &&
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test_cmp expect actual
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'
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test_expect_success !MINGW 'signals are propagated using shell convention' '
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# we use exec here to avoid any sub-shell interpretation
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# of the exit code
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git config alias.sigterm "!exec test-sigchain" &&
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test_expect_code 143 git sigterm
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'
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large_git () {
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for i in $(test_seq 1 100)
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do
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git diff --cached --binary || return
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done
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}
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test_expect_success 'create blob' '
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test-genrandom foo 16384 >file &&
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git add file
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'
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test_expect_success 'a constipated git dies with SIGPIPE' '
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OUT=$( ((large_git; echo $? 1>&3) | :) 3>&1 )
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test "$OUT" -eq 141
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'
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test_expect_success 'a constipated git dies with SIGPIPE even if parent ignores it' '
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OUT=$( ((trap "" PIPE; large_git; echo $? 1>&3) | :) 3>&1 )
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test "$OUT" -eq 141
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'
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test_done
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