linux-dev/arch/powerpc/kernel/trace, branch master

powerpc/64: provide a helper macro to load r2 with the kernel TOC

2022-09-28T09:22:12Z

A later change stops the kernel using r2 and loads it with a poison value. Provide a PACATOC loading abstraction which can hide this detail. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220926034057.2360083-5-npiggin@gmail.com

powerpc/64: asm use consistent global variable declaration and access

2022-09-28T09:22:12Z

Use helper macros to access global variables, and place them in .data sections rather than in .toc. Putting addresses in TOC is not required because the kernel is linked with a single TOC. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220926034057.2360083-3-npiggin@gmail.com

powerpc64/ftrace: Fix ftrace for clang builds

2022-08-10T05:38:16Z

Clang doesn't support -mprofile-kernel ABI, so guard the checks against CONFIG_DYNAMIC_FTRACE_WITH_REGS, rather than the elf ABI version. Fixes: 23b44fc248f4 ("powerpc/ftrace: Make __ftrace_make_{nop/call}() common to PPC32 and PPC64") Cc: stable@vger.kernel.org # v5.19+ Reported-by: Nick Desaulniers Reported-by: Ondrej Mosnacek Signed-off-by: Naveen N. Rao Tested-by: Ondrej Mosnacek Acked-by: Nick Desaulniers Signed-off-by: Michael Ellerman Link: https://github.com/llvm/llvm-project/issues/57031 Link: https://github.com/ClangBuiltLinux/linux/issues/1682 Link: https://lore.kernel.org/r/20220809095907.418764-1-naveen.n.rao@linux.vnet.ibm.com

powerpc: Fix all occurences of duplicate words

2022-07-25T02:05:15Z

Since commit 87c78b612f4f ("powerpc: Fix all occurences of "the the"") fixed "the the", there's now a steady stream of patches fixing other duplicate words. Just fix them all at once, to save the overhead of dealing with individual patches for each case. This leaves a few cases of "that that", which in some contexts is correct. Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220718095158.326606-1-mpe@ellerman.id.au

powerpc/64: Drop ppc_inst_as_str()

2022-06-29T09:37:07Z

The ppc_inst_as_str() macro tries to make printing variable length, aka "prefixed", instructions convenient. It mostly succeeds, but it does hide an on-stack buffer, which triggers stack protector. More problematically it doesn't compile at all with GCC 12, with -Wdangling-pointer, due to the fact that it returns the char buffer declared inside the macro: arch/powerpc/kernel/trace/ftrace.c: In function '__ftrace_modify_call': ./include/linux/printk.h:475:44: error: using a dangling pointer to '__str' [-Werror=dangling-pointer=] 475 | #define printk(fmt, ...) printk_index_wrap(_printk, fmt, ##__VA_ARGS__) ... arch/powerpc/kernel/trace/ftrace.c:567:17: note: in expansion of macro 'pr_err' 567 | pr_err("Not expected bl: opcode is %s\n", ppc_inst_as_str(op)); | ^~~~~~ ./arch/powerpc/include/asm/inst.h:156:14: note: '__str' declared here 156 | char __str[PPC_INST_STR_LEN]; \ | ^~~~~ This could be fixed by having the caller declare the buffer, but in some places there'd need to be two buffers. In all cases where ppc_inst_as_str() is used the output is not really meant for user consumption, it's almost always indicative of a kernel bug. A simpler solution is to just print the value as an unsigned long. For normal instructions the output is identical. For prefixed instructions the value is printed as a single 64-bit quantity, whereas previously the low half was printed first. But that is good enough for debug output, especially as prefixed instructions will be rare in kernel code in practice. Old: c000000000111170 60420000 ori r2,r2,0 c000000000111174 04100001 e580fb00 .long 0xe580fb0004100001 New: c00000000010f90c 60420000 ori r2,r2,0 c00000000010f910 e580fb0004100001 .long 0xe580fb0004100001 Reported-by: Bagas Sanjaya Reported-by: Petr Mladek Signed-off-by: Michael Ellerman Tested-by: Bagas Sanjaya Link: https://lore.kernel.org/r/20220531065936.3674348-1-mpe@ellerman.id.au

powerpc/ftrace: Remove ftrace init tramp once kernel init is complete

2022-05-22T05:58:29Z

Stop using the ftrace trampoline for init section once kernel init is complete. Fixes: 67361cf8071286 ("powerpc/ftrace: Handle large kernel configs") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Naveen N. Rao Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220516071422.463738-1-naveen.n.rao@linux.vnet.ibm.com

powerpc/ftrace: Minimise number of #ifdefs

2022-05-22T05:58:26Z

A lot of #ifdefs can be replaced by IS_ENABLED() Do so. Signed-off-by: Christophe Leroy [mpe: Fold in changes suggested by Naveen and Christophe on list] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/18ce6708d6f8c71d87436f9c6019f04df4125128.1652074503.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Simplify expected_nop_sequence()

2022-05-22T05:58:26Z

Avoid ifdefs around expected_nop_sequence(). While at it make it a bool. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/305d22472f1f92127fba09692df6bb5d079a8cd0.1652074503.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Use size macro instead of opencoding

2022-05-22T05:57:38Z

0x80000000 is SZ_2G. Use it. Signed-off-by: Christophe Leroy [mpe: Fix comparison against unsigned -SZ_2G] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/bb6626e884acffe87b58736291df57db3deaa9b9.1652074503.git.christophe.leroy@csgroup.eu

powerpc/ftrace: Use PPC_RAW_xxx() macros instead of opencoding.

2022-05-19T13:11:29Z

PPC_RAW_xxx() macros are self explanatory and less error prone than open coding. Use them in ftrace.c Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/9292094c9a69cef6d29ee83f435a557b59c45065.1652074503.git.christophe.leroy@csgroup.eu