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commit: d8b9a41d76de38cab079951cd494cdb491b55126 |
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Author: Mike Frysinger <vapier <AT> gentoo <DOT> org> |
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AuthorDate: Sun Oct 31 23:50:01 2021 +0000 |
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Commit: Mike Frysinger <vapier <AT> gentoo <DOT> org> |
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CommitDate: Sun Oct 31 23:50:01 2021 +0000 |
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URL: https://gitweb.gentoo.org/proj/sandbox.git/commit/?id=d8b9a41d |
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|
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libsandbox: do not use ptrace if it returns ENOSYS |
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|
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QEMU's linux-user does not implement ptrace for any architecture, and |
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any attempt to call it fails with ENOSYS. Detect that scenario. |
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|
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Closes: https://bugs.gentoo.org/648516 |
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Signed-off-by: Mike Frysinger <vapier <AT> gentoo.org> |
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|
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libsandbox/trace.c | 10 ++++++++-- |
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1 file changed, 8 insertions(+), 2 deletions(-) |
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|
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diff --git a/libsandbox/trace.c b/libsandbox/trace.c |
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index 4e01f6e..4ae58aa 100644 |
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--- a/libsandbox/trace.c |
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+++ b/libsandbox/trace.c |
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@@ -584,8 +584,14 @@ static char *flatten_args(char *const argv[]) |
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|
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bool trace_possible(const char *filename, char *const argv[], const void *data) |
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{ |
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- if (_trace_possible(data)) |
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- return true; |
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+ if (_trace_possible(data)) { |
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+ /* If we're in an environment like QEMU where ptrace doesn't work, then |
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+ * don't try to use it. If ptrace does work, this should fail with ESRCH. |
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+ */ |
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+ errno = 0; |
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+ ptrace(PTRACE_CONT, 0, NULL, NULL); |
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+ return errno == ENOSYS ? false : true; |
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+ } |
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|
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char *args = flatten_args(argv); |
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sb_eqawarn("Unable to trace static ELF: %s: %s\n", filename, args); |
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