# [PATCH] compat: make sure git_mmap is not expected to write 4 messages from 2018-10-23 to 2018-10-24. Participants: carlo, Johannes Schindelin, Carlo Marcelo Arenas Belón, Junio C Hamano. Thread: https://gitlist.dev/t/49644 ## carlo, 2018-10-23 05:12 Subject: [PATCH] compat: make sure git_mmap is not expected to write Message-ID: <20181023051216.64266-1-carenas@gmail.com> URL: https://gitlist.dev/e/20181023051216.64266-1-carenas%40gmail.com ``` in f48000fc ("Yank writing-back support from gitfakemmap.", 2005-10-08) support for writting back changes was removed but the specific prot flag that would be used was not checked for) Signed-off-by: Carlo Marcelo Arenas Belón --- compat/mmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/compat/mmap.c b/compat/mmap.c index 7f662fef7b..14d31010df 100644 --- a/compat/mmap.c +++ b/compat/mmap.c @@ -4,7 +4,7 @@ void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t of { size_t n = 0; - if (start != NULL || !(flags & MAP_PRIVATE)) + if (start != NULL || flags != MAP_PRIVATE || prot != PROT_READ) die("Invalid usage of mmap when built with NO_MMAP"); start = xmalloc(length); -- 2.19.1 ``` ## Johannes Schindelin, 2018-10-23 10:13 Subject: Re: [PATCH] compat: make sure git_mmap is not expected to write Message-ID: URL: https://gitlist.dev/e/nycvar.QRO.7.76.6.1810231212190.4546%40tvgsbejvaqbjf.bet In-Reply-To: <20181023051216.64266-1-carenas@gmail.com> ``` Hi carlo, your mail's "From:" line does not record your full name, but the Signed-off-by: line does. Let's use the latter? On Mon, 22 Oct 2018, carlo wrote: > in f48000fc ("Yank writing-back support from gitfakemmap.", 2005-10-08) > support for writting back changes was removed but the specific prot > flag that would be used was not checked for) > > Signed-off-by: Carlo Marcelo Arenas Belón ACK! Thank you, Johannes > --- > compat/mmap.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/compat/mmap.c b/compat/mmap.c > index 7f662fef7b..14d31010df 100644 > --- a/compat/mmap.c > +++ b/compat/mmap.c > @@ -4,7 +4,7 @@ void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t of > { > size_t n = 0; > > - if (start != NULL || !(flags & MAP_PRIVATE)) > + if (start != NULL || flags != MAP_PRIVATE || prot != PROT_READ) > die("Invalid usage of mmap when built with NO_MMAP"); > > start = xmalloc(length); > -- > 2.19.1 > > ``` ## Carlo Marcelo Arenas Belón, 2018-10-23 12:35 Subject: [PATCH v2] compat: make sure git_mmap is not expected to write Message-ID: <20181023123519.91317-1-carenas@gmail.com> URL: https://gitlist.dev/e/20181023123519.91317-1-carenas%40gmail.com In-Reply-To: ``` in f48000fc ("Yank writing-back support from gitfakemmap.", 2005-10-08) support for writting back changes was removed but the specific prot flag that would be used was not checked for Acked-by: Johannes Schindelin Signed-off-by: Carlo Marcelo Arenas Belón --- Changes in v2: * reset-author to match signature * cleanup commit message and add ACK compat/mmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/compat/mmap.c b/compat/mmap.c index 7f662fef7b..14d31010df 100644 --- a/compat/mmap.c +++ b/compat/mmap.c @@ -4,7 +4,7 @@ void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t of { size_t n = 0; - if (start != NULL || !(flags & MAP_PRIVATE)) + if (start != NULL || flags != MAP_PRIVATE || prot != PROT_READ) die("Invalid usage of mmap when built with NO_MMAP"); start = xmalloc(length); -- 2.19.1 ``` ## Junio C Hamano, 2018-10-24 01:43 Subject: Re: [PATCH v2] compat: make sure git_mmap is not expected to write Message-ID: URL: https://gitlist.dev/e/xmqqr2ggqftu.fsf%40gitster-ct.c.googlers.com In-Reply-To: <20181023123519.91317-1-carenas@gmail.com> ``` Carlo Marcelo Arenas Belón writes: > in f48000fc ("Yank writing-back support from gitfakemmap.", 2005-10-08) > support for writting back changes was removed but the specific prot > flag that would be used was not checked for > > Acked-by: Johannes Schindelin > Signed-off-by: Carlo Marcelo Arenas Belón > --- > Changes in v2: > > * reset-author to match signature > * cleanup commit message and add ACK Thanks. Looking good. > compat/mmap.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/compat/mmap.c b/compat/mmap.c > index 7f662fef7b..14d31010df 100644 > --- a/compat/mmap.c > +++ b/compat/mmap.c > @@ -4,7 +4,7 @@ void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t of > { > size_t n = 0; > > - if (start != NULL || !(flags & MAP_PRIVATE)) > + if (start != NULL || flags != MAP_PRIVATE || prot != PROT_READ) > die("Invalid usage of mmap when built with NO_MMAP"); > > start = xmalloc(length); ```