84 lines
3.9 KiB
Plaintext
84 lines
3.9 KiB
Plaintext
2002-01-19 Russell King <rmk@arm.linux.org.uk>
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* fpa11.h - Add documentation
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- remove userRegisters pointer from this structure.
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- add new method to obtain integer register values.
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* softfloat.c - Remove float128
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* softfloat.h - Remove float128
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* softfloat-specialize - Remove float128
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* The FPA11 structure is not a kernel-specific data structure.
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It is used by users of ptrace to examine the values of the
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floating point registers. Therefore, any changes to the
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FPA11 structure (size or position of elements contained
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within) have to be well thought out.
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* Since 128-bit float requires the FPA11 structure to change
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size, it has been removed. 128-bit float is currently unused,
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and needs various things to be re-worked so that we won't
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overflow the available space in the task structure.
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* The changes are designed to break any patch that goes on top
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of this code, so that the authors properly review their changes.
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1999-08-19 Scott Bambrough <scottb@netwinder.org>
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* fpmodule.c - Changed version number to 0.95
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* fpa11.h - modified FPA11, FPREG structures
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* fpa11.c - Changes due to FPA11, FPREG structure alterations.
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* fpa11_cpdo.c - Changes due to FPA11, FPREG structure alterations.
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* fpa11_cpdt.c - Changes due to FPA11, FPREG structure alterations.
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* fpa11_cprt.c - Changes due to FPA11, FPREG structure alterations.
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* single_cpdo.c - Changes due to FPA11, FPREG structure alterations.
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* double_cpdo.c - Changes due to FPA11, FPREG structure alterations.
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* extended_cpdo.c - Changes due to FPA11, FPREG structure alterations.
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* I discovered several bugs. First and worst is that the kernel
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passes in a pointer to the FPE's state area. This is defined
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as a struct user_fp (see user.h). This pointer was cast to a
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FPA11*. Unfortunately FPA11 and user_fp are of different sizes;
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user_fp is smaller. This meant that the FPE scribbled on things
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below its area, which is bad, as the area is in the thread_struct
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embedded in the process task structure. Thus we were scribbling
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over one of the most important structures in the entire OS.
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* user_fp and FPA11 have now been harmonized. Most of the changes
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in the above code were dereferencing problems due to moving the
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register type out of FPREG, and getting rid of the union variable
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fpvalue.
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* Second I noticed resetFPA11 was not always being called for a
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task. This should happen on the first floating point exception
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that occurs. It is controlled by init_flag in FPA11. The
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comment in the code beside init_flag state the kernel guarantees
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this to be zero. Not so. I found that the kernel recycles task
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structures, and that recycled ones may not have init_flag zeroed.
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I couldn't even find anything that guarantees it is zeroed when
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when the task structure is initially allocated. In any case
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I now initialize the entire FPE state in the thread structure to
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zero when allocated and recycled. See alloc_task_struct() and
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flush_thread() in arch/arm/process.c. The change to
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alloc_task_struct() may not be necessary, but I left it in for
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completeness (better safe than sorry).
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1998-11-23 Scott Bambrough <scottb@netwinder.org>
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* README.FPE - fix typo in description of lfm/sfm instructions
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* NOTES - Added file to describe known bugs/problems
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* fpmodule.c - Changed version number to 0.94
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1998-11-20 Scott Bambrough <scottb@netwinder.org>
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* README.FPE - fix description of URD, NRM instructions
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* TODO - remove URD, NRM instructions from TODO list
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* single_cpdo.c - implement URD, NRM
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* double_cpdo.c - implement URD, NRM
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* extended_cpdo.c - implement URD, NRM
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1998-11-19 Scott Bambrough <scottb@netwinder.org>
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* ChangeLog - Added this file to track changes made.
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* fpa11.c - added code to initialize register types to typeNone
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* fpa11_cpdt.c - fixed bug in storeExtended (typeExtended changed to
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typeDouble in switch statement)
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