| Message ID | 20161201051433.17168-3-bobby.prani@gmail.com |
|---|---|
| State | New |
| Headers | show |
Pranith Kumar <bobby.prani@gmail.com> writes: > From: Marc-André Lureau <marcandre.lureau@redhat.com> > > tests/tcg/mmap test fails with values other than default target page > size. When creating a map beyond EOF, extra anonymous pages are added up > to the target page boundary. Currently, this operation is performed only > when qemu_real_host_page_size < TARGET_PAGE_SIZE, but it should be > performed if the configured page size (qemu -p) is larger than > qemu_real_host_page_size too. > > (also fixes some style issues to please checkpatch) > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> > Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> but again doesn't really need to be in this series > --- > linux-user/mmap.c | 27 ++++++++++++++------------- > 1 file changed, 14 insertions(+), 13 deletions(-) > > diff --git a/linux-user/mmap.c b/linux-user/mmap.c > index 61685bf..0794a43 100644 > --- a/linux-user/mmap.c > +++ b/linux-user/mmap.c > @@ -418,31 +418,32 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, > } > > /* When mapping files into a memory area larger than the file, accesses > - to pages beyond the file size will cause a SIGBUS. > + to pages beyond the file size will cause a SIGBUS. > > For example, if mmaping a file of 100 bytes on a host with 4K pages > emulating a target with 8K pages, the target expects to be able to > access the first 8K. But the host will trap us on any access beyond > - 4K. > + 4K. > > When emulating a target with a larger page-size than the hosts, we > may need to truncate file maps at EOF and add extra anonymous pages > up to the targets page boundary. */ > > - if ((qemu_real_host_page_size < TARGET_PAGE_SIZE) > - && !(flags & MAP_ANONYMOUS)) { > - struct stat sb; > + if ((qemu_real_host_page_size < qemu_host_page_size) && > + !(flags & MAP_ANONYMOUS)) { > + struct stat sb; > > - if (fstat (fd, &sb) == -1) > - goto fail; > + if (fstat(fd, &sb) == -1) { > + goto fail; > + } > > /* Are we trying to create a map beyond EOF?. */ > - if (offset + len > sb.st_size) { > - /* If so, truncate the file map at eof aligned with > - the hosts real pagesize. Additional anonymous maps > - will be created beyond EOF. */ > - len = REAL_HOST_PAGE_ALIGN(sb.st_size - offset); > - } > + if (offset + len > sb.st_size) { > + /* If so, truncate the file map at eof aligned with > + the hosts real pagesize. Additional anonymous maps > + will be created beyond EOF. */ > + len = REAL_HOST_PAGE_ALIGN(sb.st_size - offset); > + } > } > > if (!(flags & MAP_FIXED)) { -- Alex Bennée
Le 01/12/2016 à 06:14, Pranith Kumar a écrit : > From: Marc-André Lureau <marcandre.lureau@redhat.com> > > tests/tcg/mmap test fails with values other than default target page > size. When creating a map beyond EOF, extra anonymous pages are added up > to the target page boundary. Currently, this operation is performed only > when qemu_real_host_page_size < TARGET_PAGE_SIZE, but it should be > performed if the configured page size (qemu -p) is larger than > qemu_real_host_page_size too. > > (also fixes some style issues to please checkpatch) > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> > Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> > --- > linux-user/mmap.c | 27 ++++++++++++++------------- > 1 file changed, 14 insertions(+), 13 deletions(-) > > diff --git a/linux-user/mmap.c b/linux-user/mmap.c > index 61685bf..0794a43 100644 > --- a/linux-user/mmap.c > +++ b/linux-user/mmap.c > @@ -418,31 +418,32 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, > } > > /* When mapping files into a memory area larger than the file, accesses > - to pages beyond the file size will cause a SIGBUS. > + to pages beyond the file size will cause a SIGBUS. > > For example, if mmaping a file of 100 bytes on a host with 4K pages > emulating a target with 8K pages, the target expects to be able to > access the first 8K. But the host will trap us on any access beyond > - 4K. > + 4K. You should not mix coding style update and fix: this hides what it is done in the patch: one word change. I think checkpatch only requires changes around the fix. > When emulating a target with a larger page-size than the hosts, we > may need to truncate file maps at EOF and add extra anonymous pages > up to the targets page boundary. */ > > - if ((qemu_real_host_page_size < TARGET_PAGE_SIZE) > - && !(flags & MAP_ANONYMOUS)) { > - struct stat sb; > + if ((qemu_real_host_page_size < qemu_host_page_size) && So it appears to be the fix :) Reviewed-by: Laurent Vivier <laurent@vivier.eu> Thanks, Laurent
diff --git a/linux-user/mmap.c b/linux-user/mmap.c index 61685bf..0794a43 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -418,31 +418,32 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, } /* When mapping files into a memory area larger than the file, accesses - to pages beyond the file size will cause a SIGBUS. + to pages beyond the file size will cause a SIGBUS. For example, if mmaping a file of 100 bytes on a host with 4K pages emulating a target with 8K pages, the target expects to be able to access the first 8K. But the host will trap us on any access beyond - 4K. + 4K. When emulating a target with a larger page-size than the hosts, we may need to truncate file maps at EOF and add extra anonymous pages up to the targets page boundary. */ - if ((qemu_real_host_page_size < TARGET_PAGE_SIZE) - && !(flags & MAP_ANONYMOUS)) { - struct stat sb; + if ((qemu_real_host_page_size < qemu_host_page_size) && + !(flags & MAP_ANONYMOUS)) { + struct stat sb; - if (fstat (fd, &sb) == -1) - goto fail; + if (fstat(fd, &sb) == -1) { + goto fail; + } /* Are we trying to create a map beyond EOF?. */ - if (offset + len > sb.st_size) { - /* If so, truncate the file map at eof aligned with - the hosts real pagesize. Additional anonymous maps - will be created beyond EOF. */ - len = REAL_HOST_PAGE_ALIGN(sb.st_size - offset); - } + if (offset + len > sb.st_size) { + /* If so, truncate the file map at eof aligned with + the hosts real pagesize. Additional anonymous maps + will be created beyond EOF. */ + len = REAL_HOST_PAGE_ALIGN(sb.st_size - offset); + } } if (!(flags & MAP_FIXED)) {