On Sun, Sep 24, 2017 at 12:17:51PM -0700, Kees Cook wrote: > On Thu, Sep 21, 2017 at 2:37 AM, Christophe Leroy > <christophe.leroy@xxxxxx> wrote: > > On powerpc, RODATA_TEST fails with message the following messages: > > > > [ 6.199505] Freeing unused kernel memory: 528K > > [ 6.203935] rodata_test: test data was not read only > > > > This is because GCC allocates it to .data section: > > > > c0695034 g O .data 00000004 rodata_test_data > > Uuuh... that seems like a compiler bug. It's marked "const" -- it > should never end up in .data. I would argue that this has done exactly > what it was supposed to do, and shows that something has gone wrong. > It should always be const. Adding "static" should just change > visibility. (I'm not opposed to the static change, but it seems to > paper over a problem with the compiler...) The compiler puts this item in .sdata, for 32-bit. There is no .srodata, so if it wants to use a small data section, it must use .sdata . Non-external, non-referenced symbols are not put in .sdata, that is the difference you see with the "static". I don't think there is a bug here. If you think there is, please open a GCC bug. Segher -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
