[systemd-devel] [PATCH] journal: Fix sd_journal_enumerate_unique skipping values
Jan Janssen
medhefgo at web.de
Mon Oct 6 09:36:34 PDT 2014
*bump*
On 2014-09-06 10:36, Jan Janssen wrote:
> sd_journal_enumerate_unique will lock its mmap window to prevent it
> from being released by calling mmap_cache_get with keep_always=true.
> This call may return windows that are wider, but compatible with the
> parameters provided to it.
>
> This can result in a mismatch where the window to be released cannot
> properly be selected, because we have more than one window matching the
> parameters of mmap_cache_release. Therefore, introduce a release_cookie
> to be used when releasing the window.
>
> https://bugs.freedesktop.org/show_bug.cgi?id=79380
> ---
> src/journal/journal-file.c | 2 +-
> src/journal/journal-file.h | 11 ++++-------
> src/journal/journal-verify.c | 2 +-
> src/journal/mmap-cache.c | 32 +++++++++++++++++++-------------
> src/journal/mmap-cache.h | 8 +++-----
> src/journal/sd-journal.c | 11 ++++++-----
> src/journal/test-mmap-cache.c | 10 +++++-----
> 7 files changed, 39 insertions(+), 37 deletions(-)
>
> diff --git a/src/journal/journal-file.c b/src/journal/journal-file.c
> index 7286e14..0ed51ed 100644
> --- a/src/journal/journal-file.c
> +++ b/src/journal/journal-file.c
> @@ -391,7 +391,7 @@ static int journal_file_move_to(JournalFile *f, int context, bool keep_always, u
> return -EADDRNOTAVAIL;
> }
>
> - return mmap_cache_get(f->mmap, f->fd, f->prot, context, keep_always, offset, size, &f->last_stat, ret);
> + return mmap_cache_get(f->mmap, f->fd, f->prot, context, keep_always, offset, size, &f->last_stat, ret, NULL);
> }
>
> static uint64_t minimum_header_size(Object *o) {
> diff --git a/src/journal/journal-file.h b/src/journal/journal-file.h
> index da2ef3b..da1b793 100644
> --- a/src/journal/journal-file.h
> +++ b/src/journal/journal-file.h
> @@ -212,17 +212,14 @@ static unsigned type_to_context(int type) {
> return type > 0 && type < _OBJECT_TYPE_MAX ? type : 0;
> }
>
> -static inline int journal_file_object_keep(JournalFile *f, Object *o, uint64_t offset) {
> +static inline int journal_file_object_keep(JournalFile *f, Object *o, uint64_t offset, void **release_cookie) {
> unsigned context = type_to_context(o->object.type);
> uint64_t s = le64toh(o->object.size);
>
> return mmap_cache_get(f->mmap, f->fd, f->prot, context, true,
> - offset, s, &f->last_stat, NULL);
> + offset, s, &f->last_stat, NULL, release_cookie);
> }
>
> -static inline int journal_file_object_release(JournalFile *f, Object *o, uint64_t offset) {
> - unsigned context = type_to_context(o->object.type);
> - uint64_t s = le64toh(o->object.size);
> -
> - return mmap_cache_release(f->mmap, f->fd, f->prot, context, offset, s);
> +static inline int journal_file_object_release(JournalFile *f, void *release_cookie) {
> + return mmap_cache_release(f->mmap, f->fd, release_cookie);
> }
> diff --git a/src/journal/journal-verify.c b/src/journal/journal-verify.c
> index 6c8ca8c..a1c34ac 100644
> --- a/src/journal/journal-verify.c
> +++ b/src/journal/journal-verify.c
> @@ -368,7 +368,7 @@ static int contains_uint64(MMapCache *m, int fd, uint64_t n, uint64_t p) {
>
> c = (a + b) / 2;
>
> - r = mmap_cache_get(m, fd, PROT_READ|PROT_WRITE, 0, false, c * sizeof(uint64_t), sizeof(uint64_t), NULL, (void **) &z);
> + r = mmap_cache_get(m, fd, PROT_READ|PROT_WRITE, 0, false, c * sizeof(uint64_t), sizeof(uint64_t), NULL, (void **) &z, NULL);
> if (r < 0)
> return r;
>
> diff --git a/src/journal/mmap-cache.c b/src/journal/mmap-cache.c
> index 7dbbb5e..64bc8da 100644
> --- a/src/journal/mmap-cache.c
> +++ b/src/journal/mmap-cache.c
> @@ -352,7 +352,8 @@ static int try_context(
> bool keep_always,
> uint64_t offset,
> size_t size,
> - void **ret) {
> + void **ret,
> + void **release_cookie) {
>
> Context *c;
>
> @@ -381,6 +382,8 @@ static int try_context(
>
> if (ret)
> *ret = (uint8_t*) c->window->ptr + (offset - c->window->offset);
> + if (keep_always && release_cookie)
> + *release_cookie = c->window;
> return 1;
> }
>
> @@ -392,7 +395,8 @@ static int find_mmap(
> bool keep_always,
> uint64_t offset,
> size_t size,
> - void **ret) {
> + void **ret,
> + void **release_cookie) {
>
> FileDescriptor *f;
> Window *w;
> @@ -425,6 +429,8 @@ static int find_mmap(
>
> if (ret)
> *ret = (uint8_t*) w->ptr + (offset - w->offset);
> + if (keep_always && release_cookie)
> + *release_cookie = c->window;
> return 1;
> }
>
> @@ -437,7 +443,8 @@ static int add_mmap(
> uint64_t offset,
> size_t size,
> struct stat *st,
> - void **ret) {
> + void **ret,
> + void **release_cookie) {
>
> uint64_t woffset, wsize;
> Context *c;
> @@ -521,6 +528,8 @@ static int add_mmap(
>
> if (ret)
> *ret = (uint8_t*) w->ptr + (offset - w->offset);
> + if (keep_always && release_cookie)
> + *release_cookie = c->window;
> return 1;
> }
>
> @@ -533,7 +542,8 @@ int mmap_cache_get(
> uint64_t offset,
> size_t size,
> struct stat *st,
> - void **ret) {
> + void **ret,
> + void **release_cookie) {
>
> int r;
>
> @@ -543,14 +553,14 @@ int mmap_cache_get(
> assert(size > 0);
>
> /* Check whether the current context is the right one already */
> - r = try_context(m, fd, prot, context, keep_always, offset, size, ret);
> + r = try_context(m, fd, prot, context, keep_always, offset, size, ret, release_cookie);
> if (r != 0) {
> m->n_hit ++;
> return r;
> }
>
> /* Search for a matching mmap */
> - r = find_mmap(m, fd, prot, context, keep_always, offset, size, ret);
> + r = find_mmap(m, fd, prot, context, keep_always, offset, size, ret, release_cookie);
> if (r != 0) {
> m->n_hit ++;
> return r;
> @@ -559,16 +569,13 @@ int mmap_cache_get(
> m->n_missed++;
>
> /* Create a new mmap */
> - return add_mmap(m, fd, prot, context, keep_always, offset, size, st, ret);
> + return add_mmap(m, fd, prot, context, keep_always, offset, size, st, ret, release_cookie);
> }
>
> int mmap_cache_release(
> MMapCache *m,
> int fd,
> - int prot,
> - unsigned context,
> - uint64_t offset,
> - size_t size) {
> + void *release_cookie) {
>
> FileDescriptor *f;
> Window *w;
> @@ -576,7 +583,6 @@ int mmap_cache_release(
> assert(m);
> assert(m->n_ref > 0);
> assert(fd >= 0);
> - assert(size > 0);
>
> f = hashmap_get(m->fds, INT_TO_PTR(fd + 1));
> if (!f)
> @@ -585,7 +591,7 @@ int mmap_cache_release(
> assert(f->fd == fd);
>
> LIST_FOREACH(by_fd, w, f->windows)
> - if (window_matches(w, fd, prot, offset, size))
> + if (w == release_cookie)
> break;
>
> if (!w)
> diff --git a/src/journal/mmap-cache.h b/src/journal/mmap-cache.h
> index 647555a..76e5316 100644
> --- a/src/journal/mmap-cache.h
> +++ b/src/journal/mmap-cache.h
> @@ -40,14 +40,12 @@ int mmap_cache_get(
> uint64_t offset,
> size_t size,
> struct stat *st,
> - void **ret);
> + void **ret,
> + void **release_cookie);
> int mmap_cache_release(
> MMapCache *m,
> int fd,
> - int prot,
> - unsigned context,
> - uint64_t offset,
> - size_t size);
> + void *release_cookie);
> void mmap_cache_close_fd(MMapCache *m, int fd);
> void mmap_cache_close_context(MMapCache *m, unsigned context);
>
> diff --git a/src/journal/sd-journal.c b/src/journal/sd-journal.c
> index 693707c..edb60bb 100644
> --- a/src/journal/sd-journal.c
> +++ b/src/journal/sd-journal.c
> @@ -2520,6 +2520,7 @@ _public_ int sd_journal_enumerate_unique(sd_journal *j, const void **data, size_
> size_t ol;
> bool found;
> int r;
> + void *release_cookie;
>
> /* Proceed to next data object in the field's linked list */
> if (j->unique_offset == 0) {
> @@ -2563,7 +2564,7 @@ _public_ int sd_journal_enumerate_unique(sd_journal *j, const void **data, size_
> return -EBADMSG;
> }
>
> - r = journal_file_object_keep(j->unique_file, o, j->unique_offset);
> + r = journal_file_object_keep(j->unique_file, o, j->unique_offset, &release_cookie);
> if (r < 0)
> return r;
>
> @@ -2611,13 +2612,13 @@ _public_ int sd_journal_enumerate_unique(sd_journal *j, const void **data, size_
> found = true;
> }
>
> - if (found)
> - continue;
> -
> - r = journal_file_object_release(j->unique_file, o, j->unique_offset);
> + r = journal_file_object_release(j->unique_file, release_cookie);
> if (r < 0)
> return r;
>
> + if (found)
> + continue;
> +
> r = return_data(j, j->unique_file, o, data, l);
> if (r < 0)
> return r;
> diff --git a/src/journal/test-mmap-cache.c b/src/journal/test-mmap-cache.c
> index b7bb260..778e884 100644
> --- a/src/journal/test-mmap-cache.c
> +++ b/src/journal/test-mmap-cache.c
> @@ -49,23 +49,23 @@ int main(int argc, char *argv[]) {
> assert(z >= 0);
> unlink(pz);
>
> - r = mmap_cache_get(m, x, PROT_READ, 0, false, 1, 2, NULL, &p);
> + r = mmap_cache_get(m, x, PROT_READ, 0, false, 1, 2, NULL, &p, NULL);
> assert(r >= 0);
>
> - r = mmap_cache_get(m, x, PROT_READ, 0, false, 2, 2, NULL, &q);
> + r = mmap_cache_get(m, x, PROT_READ, 0, false, 2, 2, NULL, &q, NULL);
> assert(r >= 0);
>
> assert((uint8_t*) p + 1 == (uint8_t*) q);
>
> - r = mmap_cache_get(m, x, PROT_READ, 1, false, 3, 2, NULL, &q);
> + r = mmap_cache_get(m, x, PROT_READ, 1, false, 3, 2, NULL, &q, NULL);
> assert(r >= 0);
>
> assert((uint8_t*) p + 2 == (uint8_t*) q);
>
> - r = mmap_cache_get(m, x, PROT_READ, 0, false, 16ULL*1024ULL*1024ULL, 2, NULL, &p);
> + r = mmap_cache_get(m, x, PROT_READ, 0, false, 16ULL*1024ULL*1024ULL, 2, NULL, &p, NULL);
> assert(r >= 0);
>
> - r = mmap_cache_get(m, x, PROT_READ, 1, false, 16ULL*1024ULL*1024ULL+1, 2, NULL, &q);
> + r = mmap_cache_get(m, x, PROT_READ, 1, false, 16ULL*1024ULL*1024ULL+1, 2, NULL, &q, NULL);
> assert(r >= 0);
>
> assert((uint8_t*) p + 1 == (uint8_t*) q);
>
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