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Blame SOURCES/0330-manager-flush-memory-stream-before-using-the-buffer.patch

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From 0fca5aae90d5a4e292db8db7b9c31c8390799368 Mon Sep 17 00:00:00 2001
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From: Daniel Mack <zonque@gmail.com>
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Date: Fri, 7 Mar 2014 14:43:59 +0100
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Subject: [PATCH] manager: flush memory stream before using the buffer
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When the manager receives a SIGUSR2 signal, it opens a memory stream
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with open_memstream(), uses the returned file handle for logging, and
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dumps the logged content with log_dump().
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However, the char* buffer is only safe to use after the file handle has
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been flushed with fflush, as the man pages states:
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  When the stream is closed (fclose(3)) or flushed (fflush(3)), the
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  locations pointed to by ptr and sizeloc are updated to contain,
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  respectively, a pointer to the buffer and the current size of  the
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  buffer.
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  These values remain valid only as long as the caller performs no
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  further output on the stream.  If further output is performed, then the
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  stream must again be flushed before trying to access these variables.
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Without that call, dump remains NULL and the daemon crashes in
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log_dump().
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Conflicts:
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	src/core/manager.c
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(cherry-picked from b2cdc6664ef6b56e47d38649d69b9943d9f9f5d0)
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Resolves: #1147524
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---
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 src/core/manager.c | 17 +++++++++--------
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 1 file changed, 9 insertions(+), 8 deletions(-)
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diff --git a/src/core/manager.c b/src/core/manager.c
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index 4ad26e1..e48ea36 100644
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--- a/src/core/manager.c
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+++ b/src/core/manager.c
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@@ -1536,11 +1536,12 @@ static int manager_process_signal_fd(Manager *m) {
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                 }
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                 case SIGUSR2: {
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-                        FILE *f;
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-                        char *dump = NULL;
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+                        _cleanup_free_ char *dump = NULL;
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+                        _cleanup_fclose_ FILE *f = NULL;
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                         size_t size;
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-                        if (!(f = open_memstream(&dump, &size))) {
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+                        f = open_memstream(&dump, &size);
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+                        if (!f) {
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                                 log_warning("Failed to allocate memory stream.");
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                                 break;
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                         }
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@@ -1549,16 +1550,16 @@ static int manager_process_signal_fd(Manager *m) {
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                         manager_dump_jobs(m, f, "\t");
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                         if (ferror(f)) {
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-                                fclose(f);
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-                                free(dump);
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                                 log_warning("Failed to write status stream");
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                                 break;
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                         }
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-                        fclose(f);
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-                        log_dump(LOG_INFO, dump);
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-                        free(dump);
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+                        if (fflush(f)) {
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+                                log_warning("Failed to flush status stream");
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+                                break;
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+                        }
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+                        log_dump(LOG_INFO, dump);
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                         break;
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                 }
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