# [PATCH] mingw: avoid using strbuf in syslog 3 messages from 2011-10-06 to 2011-10-06. Participants: Erik Faye-Lund, Brandon Casey. Thread: https://gitlist.dev/t/28606 ## Erik Faye-Lund, 2011-10-06 16:57 Subject: [PATCH] mingw: avoid using strbuf in syslog Message-ID: <1317920244-6320-1-git-send-email-kusmabite@gmail.com> URL: https://gitlist.dev/e/1317920244-6320-1-git-send-email-kusmabite%40gmail.com ``` strbuf can call die, which again can call syslog from git-daemon. Endless recursion is no fun; fix it by hand-rolling the logic. Signed-off-by: Erik Faye-Lund --- Fixes the problem Brandon pointed out... compat/win32/syslog.c | 26 ++++++++++++++------------ 1 files changed, 14 insertions(+), 12 deletions(-) diff --git a/compat/win32/syslog.c b/compat/win32/syslog.c index 42b95a9..3b8e2b7 100644 --- a/compat/win32/syslog.c +++ b/compat/win32/syslog.c @@ -1,5 +1,4 @@ #include "../../git-compat-util.h" -#include "../../strbuf.h" static HANDLE ms_eventlog; @@ -16,13 +15,8 @@ void openlog(const char *ident, int logopt, int facility) void syslog(int priority, const char *fmt, ...) { - struct strbuf sb = STRBUF_INIT; - struct strbuf_expand_dict_entry dict[] = { - {"1", "% 1"}, - {NULL, NULL} - }; WORD logtype; - char *str; + char *str, *pos; int str_len; va_list ap; @@ -39,11 +33,20 @@ void syslog(int priority, const char *fmt, ...) } str = malloc(str_len + 1); + if (!str) + return; /* no chance to report error */ + va_start(ap, fmt); vsnprintf(str, str_len + 1, fmt, ap); va_end(ap); - strbuf_expand(&sb, str, strbuf_expand_dict_cb, &dict); - free(str); + + while ((pos = strstr(str, "%1")) != NULL) { + str = realloc(str, ++str_len + 1); + if (!str) + return; + memmove(pos + 2, pos + 1, strlen(pos)); + pos[1] = ' '; + } switch (priority) { case LOG_EMERG: @@ -66,7 +69,6 @@ void syslog(int priority, const char *fmt, ...) } ReportEventA(ms_eventlog, logtype, 0, 0, NULL, 1, 0, - (const char **)&sb.buf, NULL); - - strbuf_release(&sb); + (const char **)&str, NULL); + free(str); } -- 1.7.6.msysgit.0.579.ga3d6f ``` ## Brandon Casey, 2011-10-06 17:27 Subject: Re: [PATCH] mingw: avoid using strbuf in syslog Message-ID: URL: https://gitlist.dev/e/CA%2BsFfMediaCnzFH6uKfVc_Bb%2BW%2BAA1nO%2BOdvB8vWjjrsD1kh9w%40mail.gmail.com In-Reply-To: <1317920244-6320-1-git-send-email-kusmabite@gmail.com> ``` On Thu, Oct 6, 2011 at 11:57 AM, Erik Faye-Lund wrote: > strbuf can call die, which again can call syslog from git-daemon. > > Endless recursion is no fun; fix it by hand-rolling the logic. > > Signed-off-by: Erik Faye-Lund > --- > Fixes the problem Brandon pointed out... Actually, Johannes should get that credit. He brought up the whole recursion issue. >  compat/win32/syslog.c |   26 ++++++++++++++------------ >  1 files changed, 14 insertions(+), 12 deletions(-) > > diff --git a/compat/win32/syslog.c b/compat/win32/syslog.c > index 42b95a9..3b8e2b7 100644 > --- a/compat/win32/syslog.c > +++ b/compat/win32/syslog.c > @@ -1,5 +1,4 @@ >  #include "../../git-compat-util.h" > -#include "../../strbuf.h" > >  static HANDLE ms_eventlog; > > @@ -16,13 +15,8 @@ void openlog(const char *ident, int logopt, int facility) > >  void syslog(int priority, const char *fmt, ...) >  { > -       struct strbuf sb = STRBUF_INIT; > -       struct strbuf_expand_dict_entry dict[] = { > -               {"1", "% 1"}, > -               {NULL, NULL} > -       }; >        WORD logtype; > -       char *str; > +       char *str, *pos; >        int str_len; >        va_list ap; > > @@ -39,11 +33,20 @@ void syslog(int priority, const char *fmt, ...) >        } > >        str = malloc(str_len + 1); > +       if (!str) > +               return; /* no chance to report error */ > + Just above this, warning() is used to at least print a message to stderr if vsnprintf() fails. It could be used here, and below when realloc fails. >        va_start(ap, fmt); >        vsnprintf(str, str_len + 1, fmt, ap); >        va_end(ap); > -       strbuf_expand(&sb, str, strbuf_expand_dict_cb, &dict); > -       free(str); > + > +       while ((pos = strstr(str, "%1")) != NULL) { > +               str = realloc(str, ++str_len + 1); > +               if (!str) > +                       return; > +               memmove(pos + 2, pos + 1, strlen(pos)); > +               pos[1] = ' '; > +       } > >        switch (priority) { >        case LOG_EMERG: -Brandon ``` ## Erik Faye-Lund, 2011-10-06 17:32 Subject: Re: [PATCH] mingw: avoid using strbuf in syslog Message-ID: URL: https://gitlist.dev/e/CABPQNSYUzmHgFO9VzHRX-or8b5h%2BHEXapBoiQDWRA_4KWi9nAQ%40mail.gmail.com In-Reply-To: ``` On Thu, Oct 6, 2011 at 7:27 PM, Brandon Casey wrote: > On Thu, Oct 6, 2011 at 11:57 AM, Erik Faye-Lund wrote: >> strbuf can call die, which again can call syslog from git-daemon. >> >> Endless recursion is no fun; fix it by hand-rolling the logic. >> >> Signed-off-by: Erik Faye-Lund >> --- >> Fixes the problem Brandon pointed out... > > Actually, Johannes should get that credit.  He brought up the whole > recursion issue. > OK, I didn't spot that one. But it's not in the commit message, though. Perhaps it should be? >>  compat/win32/syslog.c |   26 ++++++++++++++------------ >>  1 files changed, 14 insertions(+), 12 deletions(-) >> >> diff --git a/compat/win32/syslog.c b/compat/win32/syslog.c >> index 42b95a9..3b8e2b7 100644 >> --- a/compat/win32/syslog.c >> +++ b/compat/win32/syslog.c >> @@ -1,5 +1,4 @@ >>  #include "../../git-compat-util.h" >> -#include "../../strbuf.h" >> >>  static HANDLE ms_eventlog; >> >> @@ -16,13 +15,8 @@ void openlog(const char *ident, int logopt, int facility) >> >>  void syslog(int priority, const char *fmt, ...) >>  { >> -       struct strbuf sb = STRBUF_INIT; >> -       struct strbuf_expand_dict_entry dict[] = { >> -               {"1", "% 1"}, >> -               {NULL, NULL} >> -       }; >>        WORD logtype; >> -       char *str; >> +       char *str, *pos; >>        int str_len; >>        va_list ap; >> >> @@ -39,11 +33,20 @@ void syslog(int priority, const char *fmt, ...) >>        } >> >>        str = malloc(str_len + 1); >> +       if (!str) >> +               return; /* no chance to report error */ >> + > > Just above this, warning() is used to at least print a message to > stderr if vsnprintf() fails.  It could be used here, and below when > realloc fails. > Good point, so this should be squashed in: --- diff --git a/compat/win32/syslog.c b/compat/win32/syslog.c index 3b8e2b7..d015e43 100644 --- a/compat/win32/syslog.c +++ b/compat/win32/syslog.c @@ -33,8 +33,10 @@ void syslog(int priority, const char *fmt, ...) } str = malloc(str_len + 1); - if (!str) - return; /* no chance to report error */ + if (!str) { + warning("malloc failed: '%s'", strerror(errno)); + return; + } va_start(ap, fmt); vsnprintf(str, str_len + 1, fmt, ap); @@ -42,8 +44,10 @@ void syslog(int priority, const char *fmt, ...) while ((pos = strstr(str, "%1")) != NULL) { str = realloc(str, ++str_len + 1); - if (!str) + if (!str) { + warning("realloc failed: '%s'", strerror(errno)); return; + } memmove(pos + 2, pos + 1, strlen(pos)); pos[1] = ' '; } ```