pm24.git/arch/parisc/kernel/vmlinux.lds.S, branch v5.6

parisc: Move EXCEPTION_TABLE to RO_DATA segment

2019-11-04T17:22:10Z

Since the EXCEPTION_TABLE is read-only, collapse it into RO_DATA. Signed-off-by: Kees Cook Signed-off-by: Borislav Petkov Acked-by: Helge Deller Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Dave Hansen Cc: Geert Uytterhoeven Cc: Heiko Carstens Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: linux-ia64@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Cc: Michael Ellerman Cc: Michal Simek Cc: Rick Edgecombe Cc: Segher Boessenkool Cc: Sven Schnelle Cc: Will Deacon Cc: x86-ml Cc: Yoshinori Sato Link: https://lkml.kernel.org/r/20191029211351.13243-24-keescook@chromium.org

vmlinux.lds.h: Replace RW_DATA_SECTION with RW_DATA

2019-11-04T14:57:41Z

Rename RW_DATA_SECTION to RW_DATA. (Calling this a "section" is a lie, since it's multiple sections and section flags cannot be applied to the macro.) Signed-off-by: Kees Cook Signed-off-by: Borislav Petkov Acked-by: Heiko Carstens # s390 Acked-by: Geert Uytterhoeven # m68k Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Dave Hansen Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman Cc: Michal Simek Cc: Rick Edgecombe Cc: Segher Boessenkool Cc: Will Deacon Cc: x86-ml Cc: Yoshinori Sato Link: https://lkml.kernel.org/r/20191029211351.13243-14-keescook@chromium.org

vmlinux.lds.h: Replace RO_DATA_SECTION with RO_DATA

2019-11-04T14:56:16Z

Finish renaming RO_DATA_SECTION to RO_DATA. (Calling this a "section" is a lie, since it's multiple sections and section flags cannot be applied to the macro.) Signed-off-by: Kees Cook Signed-off-by: Borislav Petkov Acked-by: Heiko Carstens # s390 Acked-by: Geert Uytterhoeven # m68k Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Dave Hansen Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman Cc: Michal Simek Cc: Rick Edgecombe Cc: Segher Boessenkool Cc: Will Deacon Cc: x86-ml Cc: Yoshinori Sato Link: https://lkml.kernel.org/r/20191029211351.13243-13-keescook@chromium.org

vmlinux.lds.h: Move NOTES into RO_DATA

2019-11-04T14:34:41Z

The .notes section should be non-executable read-only data. As such, move it to the RO_DATA macro instead of being per-architecture defined. Signed-off-by: Kees Cook Signed-off-by: Borislav Petkov Acked-by: Heiko Carstens # s390 Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Dave Hansen Cc: linux-alpha@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: linux-ia64@vger.kernel.org Cc: linux-s390@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: Michael Ellerman Cc: Michal Simek Cc: Rick Edgecombe Cc: Segher Boessenkool Cc: Will Deacon Cc: x86-ml Cc: Yoshinori Sato Link: https://lkml.kernel.org/r/20191029211351.13243-11-keescook@chromium.org

parisc: add dynamic ftrace

2019-06-08T10:56:29Z

This patch implements dynamic ftrace for PA-RISC. The required mcount call sequences can get pretty long, so instead of patching the whole call sequence out of the functions, we are using -fpatchable-function-entry from gcc. This puts a configurable amount of NOPS before/at the start of the function. Taking do_sys_open() as example, which would look like this when the call is patched out: 1036b248: 08 00 02 40 nop 1036b24c: 08 00 02 40 nop 1036b250: 08 00 02 40 nop 1036b254: 08 00 02 40 nop 1036b258 : 1036b258: 08 00 02 40 nop 1036b25c: 08 03 02 41 copy r3,r1 1036b260: 6b c2 3f d9 stw rp,-14(sp) 1036b264: 08 1e 02 43 copy sp,r3 1036b268: 6f c1 01 00 stw,ma r1,80(sp) When ftrace gets enabled for this function the kernel will patch these NOPs to: 1036b248: 10 19 57 20

1036b24c: 6f c1 00 80 stw,ma r1,40(sp) 1036b250: 48 21 3f d1 ldw -18(r1),r1 1036b254: e8 20 c0 02 bv,n r0(r1) 1036b258 : 1036b258: e8 3f 1f df b,l,n .-c,r1 1036b25c: 08 03 02 41 copy r3,r1 1036b260: 6b c2 3f d9 stw rp,-14(sp) 1036b264: 08 1e 02 43 copy sp,r3 1036b268: 6f c1 01 00 stw,ma r1,80(sp) So the first NOP in do_sys_open() will be patched to jump backwards into some minimal trampoline code which pushes a stackframe, saves r1 which holds the return address, loads the address of the real ftrace function, and branches to that location. For 64 Bit things are getting a bit more complicated (and longer) because we must make sure that the address of ftrace location is 8 byte aligned, and the offset passed to ldd for fetching the address is 8 byte aligned as well. Note that gcc has a bug which misplaces the function label, and needs a patch to make dynamic ftrace work. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90751 for details. Signed-off-by: Sven Schnelle Signed-off-by: Helge Deller

parisc: Allow building 64-bit kernel without -mlong-calls compiler option

2019-05-20T08:51:39Z

A 64-bit kernel built without CONFIG_MLONGCALLS (-mlong-calls compiler option) usually fails to link because of unreachable functions. Try to work around that linking issue by moving the *.init and *.exit text segments closer to the main text segment. With that change those segments now don't get freed at runtime any longer, but since we in most cases run with huge-page enabled, we ignore the lost memory in preference of better performance. This change will not guarantee that every kernel config will now sucessfully build with short calls and without linking issues. Signed-off-by: Helge Deller

parisc: Enable the ro_after_init feature

2019-05-10T19:00:44Z

This patch modifies the initial page mapping functions in the following way: During bootup the init, text and data pages will be mapped RWX and if supported, with huge pages. At final stage of the bootup, the kernel calls free_initmem() and then all pages will be remapped either R-X (for text and read-only data) or RW- (for data). The __init pages will be dropped. This reflects the behaviour of the x86 platform. Signed-off-by: Helge Deller

parisc: Add static branch and JUMP_LABEL feature

2019-05-05T22:10:03Z

Signed-off-by: Helge Deller

parisc: Add alternative coding infrastructure

2018-10-17T15:22:26Z

This patch adds the necessary code to patch a running kernel at runtime to improve performance. The current implementation offers a few optimizations variants: - When running a SMP kernel on a single UP processor, unwanted assembler statements like locking functions are overwritten with NOPs. When multiple instructions shall be skipped, one branch instruction is used instead of multiple nop instructions. - In the UP case, some pdtlb and pitlb instructions are patched to become pdtlb,l and pitlb,l which only flushes the CPU-local tlb entries instead of broadcasting the flush to other CPUs in the system and thus may improve performance. - fic and fdc instructions are skipped if no I- or D-caches are installed. This should speed up qemu emulation and cacheless systems. - If no cache coherence is needed for IO operations, the relevant fdc and sync instructions in the sba and ccio drivers are replaced by nops. - On systems which share I- and D-TLBs and thus don't have a seperate instruction TLB, the pitlb instruction is replaced by a nop. Live-patching is done early in the boot process, just after having run the system inventory. No drivers are running and thus no external interrupts should arrive. So the hope is that no TLB exceptions will occur during the patching. If this turns out to be wrong we will probably need to do the patching in real-mode. Signed-off-by: Helge Deller

parisc64: Add .opd based function descriptor dereference

2018-01-09T09:45:38Z

We are moving towards separate kernel and module function descriptor dereference callbacks. This patch enables it for parisc64. For pointers that belong to the kernel - Added __start_opd and __end_opd pointers, to track the kernel .opd section address range; - Added dereference_kernel_function_descriptor(). Now we will dereference only function pointers that are within [__start_opd, __end_opd); For pointers that belong to a module - Added dereference_module_function_descriptor() to handle module function descriptor dereference. Now we will dereference only pointers that are within [module->opd.start, module->opd.end). Link: http://lkml.kernel.org/r/20171109234830.5067-5-sergey.senozhatsky@gmail.com To: Tony Luck To: Fenghua Yu To: Helge Deller To: Benjamin Herrenschmidt To: Paul Mackerras To: Michael Ellerman To: James Bottomley Cc: Andrew Morton Cc: Jessica Yu Cc: Steven Rostedt Cc: linux-ia64@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Sergey Senozhatsky Tested-by: Helge Deller #parisc64 Signed-off-by: Petr Mladek