| Message ID | 20210505170055.1415360-6-philmd@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | misc: Replace alloca() by g_malloc() | expand |
On Wed, May 05, 2021 at 07:00:55PM +0200, Philippe Mathieu-Daudé wrote: > The ALLOCA(3) man-page mentions its "use is discouraged". > > Replace it by a g_malloc() call. > > Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Acked-by: David Gibson <david@gibson.dropbear.id.au> > --- > target/ppc/kvm.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c > index 104a308abb5..ae62daddf7d 100644 > --- a/target/ppc/kvm.c > +++ b/target/ppc/kvm.c > @@ -2698,11 +2698,11 @@ int kvmppc_save_htab(QEMUFile *f, int fd, size_t bufsize, int64_t max_ns) > int kvmppc_load_htab_chunk(QEMUFile *f, int fd, uint32_t index, > uint16_t n_valid, uint16_t n_invalid, Error **errp) > { > - struct kvm_get_htab_header *buf; > - size_t chunksize = sizeof(*buf) + n_valid * HASH_PTE_SIZE_64; > + size_t chunksize = sizeof(struct kvm_get_htab_header) > + + n_valid * HASH_PTE_SIZE_64; > ssize_t rc; > + g_autofree struct kvm_get_htab_header *buf = g_malloc(chunksize); > > - buf = alloca(chunksize); > buf->index = index; > buf->n_valid = n_valid; > buf->n_invalid = n_invalid; > @@ -2741,10 +2741,10 @@ void kvmppc_read_hptes(ppc_hash_pte64_t *hptes, hwaddr ptex, int n) > i = 0; > while (i < n) { > struct kvm_get_htab_header *hdr; > + char buf[sizeof(*hdr) + HPTES_PER_GROUP * HASH_PTE_SIZE_64]; > int m = n < HPTES_PER_GROUP ? n : HPTES_PER_GROUP; > - char buf[sizeof(*hdr) + m * HASH_PTE_SIZE_64]; > > - rc = read(fd, buf, sizeof(buf)); > + rc = read(fd, buf, sizeof(*hdr) + m * HASH_PTE_SIZE_64); > if (rc < 0) { > hw_error("kvmppc_read_hptes: Unable to read HPTEs"); > }
On Wed, 5 May 2021 19:00:55 +0200 Philippe Mathieu-Daudé <philmd@redhat.com> wrote: > The ALLOCA(3) man-page mentions its "use is discouraged". > > Replace it by a g_malloc() call. > > Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> > --- > target/ppc/kvm.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c > index 104a308abb5..ae62daddf7d 100644 > --- a/target/ppc/kvm.c > +++ b/target/ppc/kvm.c > @@ -2698,11 +2698,11 @@ int kvmppc_save_htab(QEMUFile *f, int fd, size_t bufsize, int64_t max_ns) > int kvmppc_load_htab_chunk(QEMUFile *f, int fd, uint32_t index, > uint16_t n_valid, uint16_t n_invalid, Error **errp) > { > - struct kvm_get_htab_header *buf; > - size_t chunksize = sizeof(*buf) + n_valid * HASH_PTE_SIZE_64; > + size_t chunksize = sizeof(struct kvm_get_htab_header) It is a bit unfortunate to introduce a new dependency on the struct type. What about the following ? - struct kvm_get_htab_header *buf; + g_autofree struct kvm_get_htab_header *buf = NULL; size_t chunksize = sizeof(*buf) + n_valid * HASH_PTE_SIZE_64; ssize_t rc; - buf = alloca(chunksize); + buf = g_malloc(chunksize); g_autofree struct kvm_get_htab_header *buf = NULL; size_t chunksize = sizeof(*buf) + n_valid * HASH_PTE_SIZE_64; > + + n_valid * HASH_PTE_SIZE_64; > ssize_t rc; > + g_autofree struct kvm_get_htab_header *buf = g_malloc(chunksize); > > - buf = alloca(chunksize); > buf->index = index; > buf->n_valid = n_valid; > buf->n_invalid = n_invalid; > @@ -2741,10 +2741,10 @@ void kvmppc_read_hptes(ppc_hash_pte64_t *hptes, hwaddr ptex, int n) > i = 0; > while (i < n) { > struct kvm_get_htab_header *hdr; > + char buf[sizeof(*hdr) + HPTES_PER_GROUP * HASH_PTE_SIZE_64]; > int m = n < HPTES_PER_GROUP ? n : HPTES_PER_GROUP; > - char buf[sizeof(*hdr) + m * HASH_PTE_SIZE_64]; > > - rc = read(fd, buf, sizeof(buf)); > + rc = read(fd, buf, sizeof(*hdr) + m * HASH_PTE_SIZE_64); > if (rc < 0) { > hw_error("kvmppc_read_hptes: Unable to read HPTEs"); > }
On 5/6/21 10:41 AM, Greg Kurz wrote: > On Wed, 5 May 2021 19:00:55 +0200 > Philippe Mathieu-Daudé <philmd@redhat.com> wrote: > >> The ALLOCA(3) man-page mentions its "use is discouraged". >> >> Replace it by a g_malloc() call. >> >> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> >> --- >> target/ppc/kvm.c | 10 +++++----- >> 1 file changed, 5 insertions(+), 5 deletions(-) >> >> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c >> index 104a308abb5..ae62daddf7d 100644 >> --- a/target/ppc/kvm.c >> +++ b/target/ppc/kvm.c >> @@ -2698,11 +2698,11 @@ int kvmppc_save_htab(QEMUFile *f, int fd, size_t bufsize, int64_t max_ns) >> int kvmppc_load_htab_chunk(QEMUFile *f, int fd, uint32_t index, >> uint16_t n_valid, uint16_t n_invalid, Error **errp) >> { >> - struct kvm_get_htab_header *buf; >> - size_t chunksize = sizeof(*buf) + n_valid * HASH_PTE_SIZE_64; >> + size_t chunksize = sizeof(struct kvm_get_htab_header) > > It is a bit unfortunate to introduce a new dependency on the struct type. > > What about the following ? > > - struct kvm_get_htab_header *buf; > + g_autofree struct kvm_get_htab_header *buf = NULL; > size_t chunksize = sizeof(*buf) + n_valid * HASH_PTE_SIZE_64; > ssize_t rc; > > - buf = alloca(chunksize); > + buf = g_malloc(chunksize); OK.
diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c index 104a308abb5..ae62daddf7d 100644 --- a/target/ppc/kvm.c +++ b/target/ppc/kvm.c @@ -2698,11 +2698,11 @@ int kvmppc_save_htab(QEMUFile *f, int fd, size_t bufsize, int64_t max_ns) int kvmppc_load_htab_chunk(QEMUFile *f, int fd, uint32_t index, uint16_t n_valid, uint16_t n_invalid, Error **errp) { - struct kvm_get_htab_header *buf; - size_t chunksize = sizeof(*buf) + n_valid * HASH_PTE_SIZE_64; + size_t chunksize = sizeof(struct kvm_get_htab_header) + + n_valid * HASH_PTE_SIZE_64; ssize_t rc; + g_autofree struct kvm_get_htab_header *buf = g_malloc(chunksize); - buf = alloca(chunksize); buf->index = index; buf->n_valid = n_valid; buf->n_invalid = n_invalid; @@ -2741,10 +2741,10 @@ void kvmppc_read_hptes(ppc_hash_pte64_t *hptes, hwaddr ptex, int n) i = 0; while (i < n) { struct kvm_get_htab_header *hdr; + char buf[sizeof(*hdr) + HPTES_PER_GROUP * HASH_PTE_SIZE_64]; int m = n < HPTES_PER_GROUP ? n : HPTES_PER_GROUP; - char buf[sizeof(*hdr) + m * HASH_PTE_SIZE_64]; - rc = read(fd, buf, sizeof(buf)); + rc = read(fd, buf, sizeof(*hdr) + m * HASH_PTE_SIZE_64); if (rc < 0) { hw_error("kvmppc_read_hptes: Unable to read HPTEs"); }
The ALLOCA(3) man-page mentions its "use is discouraged". Replace it by a g_malloc() call. Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> --- target/ppc/kvm.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)