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69e8544cd0
This is a preparatory patch for change in "struct pt_regs"
handling in entry_64.S.
trace_hardirqs*() thunks were (ab)using a part of the
'pt_regs' handling code, namely the SAVE_ARGS/RESTORE_ARGS
macros, to save/restore registers across C function calls.
Since SAVE_ARGS is going to be changed, open-code
register saving/restoring here.
Incidentally, this removes a bit of dead code:
one SAVE_ARGS was used just to emit a CFI annotation,
but it also generated unreachable assembly instructions.
Take a page from thunk_32.S and use push/pop instructions
instead of movq, they are far shorter:
1 or 2 bytes versus 5, and no need for instructions to adjust %rsp:
text data bss dec hex filename
333 40 0 373 175 thunk_64_movq.o
104 40 0 144 90 thunk_64_push_pop.o
[ This is ugly as sin, but we'll fix up the ugliness in the next
patch. I see no point in reordering patches just to avoid an
ugly intermediate state. --Andy ]
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1420927210-19738-4-git-send-email-dvlasenk@redhat.com
Link: http://lkml.kernel.org/r/4c979ad604f0f02c5ade3b3da308b53eabd5e198.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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|---|---|---|
| .. | ||
| .gitignore | ||
| atomic64_32.c | ||
| atomic64_386_32.S | ||
| atomic64_cx8_32.S | ||
| cache-smp.c | ||
| checksum_32.S | ||
| clear_page_64.S | ||
| cmdline.c | ||
| cmpxchg8b_emu.S | ||
| cmpxchg16b_emu.S | ||
| copy_page_64.S | ||
| copy_user_64.S | ||
| copy_user_nocache_64.S | ||
| csum-copy_64.S | ||
| csum-partial_64.c | ||
| csum-wrappers_64.c | ||
| delay.c | ||
| getuser.S | ||
| inat.c | ||
| insn.c | ||
| iomap_copy_64.S | ||
| Makefile | ||
| memcpy_32.c | ||
| memcpy_64.S | ||
| memmove_64.S | ||
| memset_64.S | ||
| misc.c | ||
| mmx_32.c | ||
| msr-reg-export.c | ||
| msr-reg.S | ||
| msr-smp.c | ||
| msr.c | ||
| putuser.S | ||
| rwsem.S | ||
| string_32.c | ||
| strstr_32.c | ||
| thunk_32.S | ||
| thunk_64.S | ||
| usercopy.c | ||
| usercopy_32.c | ||
| usercopy_64.c | ||
| x86-opcode-map.txt | ||