diff options
Diffstat (limited to 'x11/libxcb/files/patch-64bit-packed')
| -rw-r--r-- | x11/libxcb/files/patch-64bit-packed | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/x11/libxcb/files/patch-64bit-packed b/x11/libxcb/files/patch-64bit-packed new file mode 100644 index 000000000000..467c9d95fa04 --- /dev/null +++ b/x11/libxcb/files/patch-64bit-packed @@ -0,0 +1,102 @@ +From 3b72a2c9d1d656c74c691a45689e1d637f669e3a Mon Sep 17 00:00:00 2001 +From: Kenneth Graunke <kenneth@whitecape.org> +Date: Fri, 03 Jan 2014 23:08:33 +0000 +Subject: Force XCB event structures with 64-bit extended fields to be packed. + +With the advent of the Present extension, some events (such as +PresentCompleteNotify) now use native 64-bit types on the wire. + +For XGE events, we insert an extra "uint32_t full_sequence" field +immediately after the first 32 bytes of data. Normally, this causes +the subsequent fields to be shifted over by 4 bytes, and the structure +to grow in size by 4 bytes. Everything works fine. + +However, if event contains 64-bit extended fields, this may result in +the compiler adding an extra 4 bytes of padding so that those fields +remain aligned on 64-bit boundaries. This causes the structure to grow +by 8 bytes, not 4. Unfortunately, XCB doesn't realize this, and +always believes that the length only increased by 4. read_packet() +then fails to malloc enough memory to hold the event, and the event +processing code uses the wrong offsets. + +To fix this, mark any event structures containing 64-bit extended +fields with __attribute__((__packed__)). + +v2: Use any(...) instead of True in (...), as suggested by + Daniel Martin. + +v3 (Alan Coopersmith): Fix build with Solaris Studio 12.3 by moving the +attribute to after the structure definition. + +Signed-off-by: Kenneth Graunke <kenneth@whitecape.org> +Reviewed-by: Keith Packard <keithp@keithp.com> [v1] +Reviewed-by: Josh Triplett <josh@joshtriplett.org> [v1] +Reviewed-by: Daniel Martin <consume.noise@gmail.com> +Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com> +--- +diff --git a/src/c_client.py b/src/c_client.py +index 99fd307..45de544 100644 +--- src/c_client.py ++++ src/c_client.py +@@ -1762,7 +1762,7 @@ def c_simple(self, name): + # Iterator + _c_iterator(self, name) + +-def _c_complex(self): ++def _c_complex(self, force_packed = False): + ''' + Helper function for handling all structure types. + Called for all structs, requests, replies, events, errors. +@@ -1817,7 +1817,7 @@ def _c_complex(self): + if b.type.has_name: + _h(' } %s;', b.c_field_name) + +- _h('} %s;', self.c_type) ++ _h('} %s%s;', 'XCB_PACKED ' if force_packed else '', self.c_type) + + def c_struct(self, name): + ''' +@@ -2902,6 +2902,7 @@ def c_event(self, name): + # events while generating the structure for them. Otherwise we would read + # garbage (the internal full_sequence) when accessing normal event fields + # there. ++ force_packed = False + if hasattr(self, 'is_ge_event') and self.is_ge_event and self.name == name: + event_size = 0 + for field in self.fields: +@@ -2911,6 +2912,11 @@ def c_event(self, name): + full_sequence = Field(tcard32, tcard32.name, 'full_sequence', False, True, True) + idx = self.fields.index(field) + self.fields.insert(idx + 1, full_sequence) ++ ++ # If the event contains any 64-bit extended fields, they need ++ # to remain aligned on a 64-bit boundary. Adding full_sequence ++ # would normally break that; force the struct to be packed. ++ force_packed = any(f.type.size == 8 and f.type.is_simple for f in self.fields[(idx+1):]) + break + + _c_type_setup(self, name, ('event',)) +@@ -2920,7 +2926,7 @@ def c_event(self, name): + + if self.name == name: + # Structure definition +- _c_complex(self) ++ _c_complex(self, force_packed) + else: + # Typedef + _h('') +diff --git a/src/xcb.h b/src/xcb.h +index e62c985..73c77a3 100644 +--- src/xcb.h ++++ src/xcb.h +@@ -51,6 +51,8 @@ extern "C" { + * @file xcb.h + */ + ++#define XCB_PACKED __attribute__((__packed__)) ++ + /** + * @defgroup XCB_Core_API XCB Core API + * @brief Core API of the XCB library. +-- +cgit v0.9.0.2-2-gbebe |