Re: [PATCH] sparc: Improve setjmp()
Brian Inglis <[email protected]>
| Newsgroups | gmane.comp.lib.newlib |
|---|---|
| Organization | Inglis |
| Message-ID | <[email protected]> |
On 2023-10-12 03:39, Sebastian Huber wrote: > On 06.10.23 07:31, Sebastian Huber wrote: >> Flush the windows in setjmp(). This helps if the stack is changed after >> the setjmp() and we want to jump back to the original stack using >> longjmp(). >> --- >> newlib/libc/machine/sparc/setjmp.S | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/newlib/libc/machine/sparc/setjmp.S >> b/newlib/libc/machine/sparc/setjmp.S >> index 613df2ba2..d7185be4c 100644 >> --- a/newlib/libc/machine/sparc/setjmp.S >> +++ b/newlib/libc/machine/sparc/setjmp.S >> @@ -110,6 +110,8 @@ >> ENTRY(setjmp) >> ENTRY(_setjmp) >> + ta 0x03 /* Flush registers, just in case another stack >> + is used after the setjmp(). */ >> st %sp, [%o0] /* caller's stack pointer */ >> st %i7, [%o0+4] /* caller's return pc */ >> st %fp, [%o0+8] /* store caller's frame pointer */ > > I am not sure if there is anyone left being able to review this change. Hopefully someone is, but as a former SunOS/Sparc guy (sysadmin/board swapper but not assembler there) I got interested, and found one related discussion on the sparclinux list: https://lore.kernel.org/sparclinux/[email protected]/t/#u which seems to indicate that you are DTRT; also for comparison: https://gcc.gnu.org/onlinedocs/gcc/Nonlocal-Gotos.html and $ info gcc 'nonlocal gotos' although: https://stackoverflow.com/questions/72711501/special-treatment-of-setjmp-longjmp-by-compilers https://gcc.gnu.org/legacy-ml/gcc/2018-03/msg00032.html https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83368 and some threads about LLVM enhancing and dropping Sparc __builtin_set/longjmp. But as Knuth said about some code: "I have proved it correct, but not tested it.", which is the proof of the pudding: issue before patch; no issues after patch? -- Take care. Thanks, Brian Inglis Calgary, Alberta, Canada La perfection est atteinte Perfection is achieved non pas lorsqu'il n'y a plus rien à ajouter not when there is no more to add mais lorsqu'il n'y a plus rien à retirer but when there is no more to cut -- Antoine de Saint-Exupéry