Re: [Qemu-block] [PATCH 0/3] block/qcow*: Don't take address of fields in packed structs
On 10 October 2018 at 11:55, Kevin Wolf wrote: > Am 09.10.2018 um 19:24 hat Peter Maydell geschrieben: >> Taking the address of a field in a packed struct is a bad idea, because >> it might not be actually aligned enough for that pointer type (and >> thus cause a crash on dereference on some host architectures). Newer >> versions of clang warn about this. Avoid the bug by not using the >> "modify in place" byte swapping functions. >> >> There are a few places in the affected files where the in-place swap >> function is used on something other than a packed struct field; we >> convert those anyway, for consistency. >> >> Patches produced mechanically using spatch; in one case I also >> did a little hand-editing to wrap overlong lines that checkpatch >> would otherwise complain about. >> >> (clang also complains about other files in block: vdi.c, vpc.c, >> vhdx.h, vhdx.c, vhdx-endian.c, vhdx-log.c -- I may produce patches >> for those later if nobody else gets there first.) >> >> thanks >> -- PMM >> >> Peter Maydell (3): >> block/qcow2: Don't take address of fields in packed structs >> block/qcow: Don't take address of fields in packed structs >> block/qcow2-bitmap: Don't take address of fields in packed structs > > Thanks, applied to the block branch. Ping? This doesn't seem to have made it into master, unless I've missed it... thanks -- PMM
Re: [Qemu-block] [PATCH 0/3] block/qcow*: Don't take address of fields in packed structs
Am 09.10.2018 um 19:24 hat Peter Maydell geschrieben: > Taking the address of a field in a packed struct is a bad idea, because > it might not be actually aligned enough for that pointer type (and > thus cause a crash on dereference on some host architectures). Newer > versions of clang warn about this. Avoid the bug by not using the > "modify in place" byte swapping functions. > > There are a few places in the affected files where the in-place swap > function is used on something other than a packed struct field; we > convert those anyway, for consistency. > > Patches produced mechanically using spatch; in one case I also > did a little hand-editing to wrap overlong lines that checkpatch > would otherwise complain about. > > (clang also complains about other files in block: vdi.c, vpc.c, > vhdx.h, vhdx.c, vhdx-endian.c, vhdx-log.c -- I may produce patches > for those later if nobody else gets there first.) > > thanks > -- PMM > > Peter Maydell (3): > block/qcow2: Don't take address of fields in packed structs > block/qcow: Don't take address of fields in packed structs > block/qcow2-bitmap: Don't take address of fields in packed structs Thanks, applied to the block branch. Kevin
Re: [Qemu-block] [PATCH 0/3] block/qcow*: Don't take address of fields in packed structs
On 10/09/2018 01:24 PM, Peter Maydell wrote: > Taking the address of a field in a packed struct is a bad idea, because > it might not be actually aligned enough for that pointer type (and > thus cause a crash on dereference on some host architectures). Newer > versions of clang warn about this. Avoid the bug by not using the > "modify in place" byte swapping functions. > > There are a few places in the affected files where the in-place swap > function is used on something other than a packed struct field; we > convert those anyway, for consistency. > > Patches produced mechanically using spatch; in one case I also > did a little hand-editing to wrap overlong lines that checkpatch > would otherwise complain about. > > (clang also complains about other files in block: vdi.c, vpc.c, > vhdx.h, vhdx.c, vhdx-endian.c, vhdx-log.c -- I may produce patches > for those later if nobody else gets there first.) > > thanks > -- PMM > > Peter Maydell (3): > block/qcow2: Don't take address of fields in packed structs > block/qcow: Don't take address of fields in packed structs > block/qcow2-bitmap: Don't take address of fields in packed structs > > block/qcow.c | 18 ++--- > block/qcow2-bitmap.c | 24 - > block/qcow2.c| 64 +++- > 3 files changed, 55 insertions(+), 51 deletions(-) > Tested-by: John Snow Reviewed-by: John Snow
[Qemu-block] [PATCH 0/3] block/qcow*: Don't take address of fields in packed structs
Taking the address of a field in a packed struct is a bad idea, because it might not be actually aligned enough for that pointer type (and thus cause a crash on dereference on some host architectures). Newer versions of clang warn about this. Avoid the bug by not using the "modify in place" byte swapping functions. There are a few places in the affected files where the in-place swap function is used on something other than a packed struct field; we convert those anyway, for consistency. Patches produced mechanically using spatch; in one case I also did a little hand-editing to wrap overlong lines that checkpatch would otherwise complain about. (clang also complains about other files in block: vdi.c, vpc.c, vhdx.h, vhdx.c, vhdx-endian.c, vhdx-log.c -- I may produce patches for those later if nobody else gets there first.) thanks -- PMM Peter Maydell (3): block/qcow2: Don't take address of fields in packed structs block/qcow: Don't take address of fields in packed structs block/qcow2-bitmap: Don't take address of fields in packed structs block/qcow.c | 18 ++--- block/qcow2-bitmap.c | 24 - block/qcow2.c| 64 +++- 3 files changed, 55 insertions(+), 51 deletions(-) -- 2.19.0
