kernel.git/arch/parisc/kernel/Makefile, branch linux-5.16.y

parisc: add support for TOC (transfer of control)

2021-11-01T06:35:59Z

Almost all PA-RISC machines have either a button that is labeled with 'TOC' or a BMC function to trigger a TOC. TOC is a non-maskable interrupt that is sent to the processor. This can be used for diagnostic purposes like obtaining a stack trace/register dump or to enter KDB/KGDB. As an example, on my c8000, TOC can be used with: CONFIG_KGDB=y CONFIG_KGDB_KDB=y and the 'kgdboc=ttyS0,115200' appended to the command line. Press ^[( on serial console, which will enter the BMC command line, and enter 'TOC s': root@(none):/# ( cli>TOC s Sending TOC/INIT. 2800035d03e00000 0000000040c21ac8 CC_ERR_CHECK_TOC 2800035d00e00000 0000000040c21ad0 CC_ERR_CHECK_TOC 2800035d02e00000 0000000040c21ac8 CC_ERR_CHECK_TOC 2800035d01e00000 0000000040c21ad0 CC_ERR_CHECK_TOC 37000f7303e00000 2000000000000000 CC_ERR_CPU_CHECK_SUMMARY 37000f7300e00000 2000000000000000 CC_ERR_CPU_CHECK_SUMMARY 37000f7302e00000 2000000000000000 CC_ERR_CPU_CHECK_SUMMARY 37000f7301e00000 2000000000000000 CC_ERR_CPU_CHECK_SUMMARY 4300100803e00000 c0000000001d26cc CC_MC_BR_TO_OS_TOC 4300100800e00000 c0000000001d26cc CC_MC_BR_TO_OS_TOC 4300100802e00000 c0000000001d26cc CC_MC_BR_TO_OS_TOC 4300100801e00000 c0000000001d26cc CC_MC_BR_TO_OS_TOC Entering kdb (current=0x00000000411cef80, pid 0) on processor 0 due to NonMaskable Interrupt @ 0x40c21ad0 [0]kdb> Signed-off-by: Sven Schnelle Signed-off-by: Helge Deller

parisc: fix compilation when KEXEC=n and KEXEC_FILE=y

2019-12-15T20:05:38Z

Fix compilation when the CONFIG_KEXEC_FILE=y and CONFIG_KEXEC=n. Reported-by: kbuild test robot Signed-off-by: Sven Schnelle Signed-off-by: Helge Deller

parisc: add support for kexec_file_load() syscall

2019-09-08T13:41:46Z

Signed-off-by: Sven Schnelle Signed-off-by: Helge Deller

parisc: add kexec syscall support

2019-09-08T13:37:04Z

Signed-off-by: Sven Schnelle Signed-off-by: Helge Deller

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: Add static branch and JUMP_LABEL feature

2019-05-05T22:10:03Z

Signed-off-by: Helge Deller

parisc: Implement kprobes

2019-05-03T21:47:39Z

Implement kprobes support for PA-RISC. Signed-off-by: Sven Schnelle Signed-off-by: Helge Deller

parisc: add KGDB support

2019-05-03T21:47:38Z

This patch add KGDB support to PA-RISC. It also implements single-stepping utilizing the recovery counter. Signed-off-by: Sven Schnelle Signed-off-by: Helge Deller

parisc: add parisc code patching

2019-05-03T21:47:38Z

Instead of re-mapping the whole kernel text with RWX rights add a patch_text() which can be used to replace instructions in the kernel .text section. Based on the ARM implementation. Signed-off-by: Sven Schnelle Signed-off-by: Helge Deller

parisc: Split out alternative live patching code

2018-12-10T06:47:50Z

Move the alternative implemenation coding to alternative.c and add code to patch modules while loading. Signed-off-by: Helge Deller