Commit f1a60dbf authored Dec 06, 2006 by Andrew Morton Committed by Linus Torvalds Dec 07, 2006

[PATCH] gcc-4.1.0 is bust



Keith says

Compiling 2.6.19-rc6 with gcc version 4.1.0 (SUSE Linux), wait_hpet_tick is
optimized away to a never ending loop and the kernel hangs on boot in timer
setup.

0000001a <wait_hpet_tick>:
  1a:   55                      push   %ebp
  1b:   89 e5                   mov    %esp,%ebp
  1d:   eb fe                   jmp    1d <wait_hpet_tick+0x3>

This is not a problem with gcc 3.3.5.  Adding barrier() calls to
wait_hpet_tick does not help, making the variables volatile does.

And the consensus is that gcc-4.1.0 is busted.  Suse went and shipped
gcc-4.1.0 so we cannot ban it.  Add a warning.

Cc: Keith Owens <kaos@ocs.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent a4ed06ad

init/main.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -73,6 +73,10 @@
		#error Sorry, your GCC is too old. It builds incorrect kernels.
		#endif

		#if __GNUC__ == 4 && __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ == 0
		#warning gcc-4.1.0 is known to miscompile the kernel. A different compiler version is recommended.
		#endif

		static int init(void *);

		extern void init_IRQ(void);

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