* [PATCH 5.15 259/567] perf llvm: Fix inadvertent file creation
[not found] <20230307165905.838066027@linuxfoundation.org>
@ 2023-03-07 16:59 ` Greg Kroah-Hartman
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From: Greg Kroah-Hartman @ 2023-03-07 16:59 UTC (permalink / raw)
To: stable
Cc: Greg Kroah-Hartman, patches, Ian Rogers, Alexander Shishkin,
Andrii Nakryiko, bpf, Ingo Molnar, Jiri Olsa, llvm, Mark Rutland,
Namhyung Kim, Nathan Chancellor, Nick Desaulniers, Peter Zijlstra,
Tom Rix, Arnaldo Carvalho de Melo, Sasha Levin
From: Ian Rogers <irogers@google.com>
[ Upstream commit 9f19aab47ced012eddef1e2bc96007efc7713b61 ]
The LLVM template is first echo-ed into command_out and then
command_out executed. The echo surrounds the template with double
quotes, however, the template itself may contain quotes. This is
generally innocuous but in tools/perf/tests/bpf-script-test-prologue.c
we see:
...
SEC("func=null_lseek file->f_mode offset orig")
...
where the first double quote ends the double quote of the echo, then
the > redirects output into a file called f_mode.
To avoid this inadvertent behavior substitute redirects and similar
characters to be ASCII control codes, then substitute the output in
the echo back again.
Fixes: 5eab5a7ee032acaa ("perf llvm: Display eBPF compiling command in debug output")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: bpf@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: llvm@lists.linux.dev
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20230105082609.344538-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/util/llvm-utils.c | 25 ++++++++++++++++++++++++-
1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c
index 96c8ef60f4f84..8ee3a947b1599 100644
--- a/tools/perf/util/llvm-utils.c
+++ b/tools/perf/util/llvm-utils.c
@@ -531,14 +531,37 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
pr_debug("llvm compiling command template: %s\n", template);
+ /*
+ * Below, substitute control characters for values that can cause the
+ * echo to misbehave, then substitute the values back.
+ */
err = -ENOMEM;
- if (asprintf(&command_echo, "echo -n \"%s\"", template) < 0)
+ if (asprintf(&command_echo, "echo -n \a%s\a", template) < 0)
goto errout;
+#define SWAP_CHAR(a, b) do { if (*p == a) *p = b; } while (0)
+ for (char *p = command_echo; *p; p++) {
+ SWAP_CHAR('<', '\001');
+ SWAP_CHAR('>', '\002');
+ SWAP_CHAR('"', '\003');
+ SWAP_CHAR('\'', '\004');
+ SWAP_CHAR('|', '\005');
+ SWAP_CHAR('&', '\006');
+ SWAP_CHAR('\a', '"');
+ }
err = read_from_pipe(command_echo, (void **) &command_out, NULL);
if (err)
goto errout;
+ for (char *p = command_out; *p; p++) {
+ SWAP_CHAR('\001', '<');
+ SWAP_CHAR('\002', '>');
+ SWAP_CHAR('\003', '"');
+ SWAP_CHAR('\004', '\'');
+ SWAP_CHAR('\005', '|');
+ SWAP_CHAR('\006', '&');
+ }
+#undef SWAP_CHAR
pr_debug("llvm compiling command : %s\n", command_out);
err = read_from_pipe(template, &obj_buf, &obj_buf_sz);
--
2.39.2
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