kernel.git/arch/powerpc/xmon, branch linux-4.14.y

powerpc/xmon: Change printk() to pr_cont()

2020-12-29T12:47:08Z

commit 7c6c86b36a36dd4a13d30bba07718e767aa2e7a1 upstream. Since some time now, printk() adds carriage return, leading to unusable xmon output if there is no udbg backend available: [ 54.288722] sysrq: Entering xmon [ 54.292209] Vector: 0 at [cace3d2c] [ 54.292274] pc: [ 54.292331] c0023650 [ 54.292468] : xmon+0x28/0x58 [ 54.292519] [ 54.292574] lr: [ 54.292630] c0023724 [ 54.292749] : sysrq_handle_xmon+0xa4/0xfc [ 54.292801] [ 54.292867] sp: cace3de8 [ 54.292931] msr: 9032 [ 54.292999] current = 0xc28d0000 [ 54.293072] pid = 377, comm = sh [ 54.293157] Linux version 5.10.0-rc6-s3k-dev-01364-gedf13f0ccd76-dirty (root@po17688vm.idsi0.si.c-s.fr) (powerpc64-linux-gcc (GCC) 10.1.0, GNU ld (GNU Binutils) 2.34) #4211 PREEMPT Fri Dec 4 09:32:11 UTC 2020 [ 54.293287] enter ? for help [ 54.293470] [cace3de8] [ 54.293532] c0023724 [ 54.293654] sysrq_handle_xmon+0xa4/0xfc [ 54.293711] (unreliable) ... [ 54.296002] [ 54.296159] --- Exception: c01 (System Call) at [ 54.296217] 0fd4e784 [ 54.296303] [ 54.296375] SP (7fca6ff0) is in userspace [ 54.296431] mon> [ 54.296484] Use pr_cont() instead. Fixes: 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing continuation lines") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Christophe Leroy [mpe: Mention that it only happens when udbg is not available] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/c8a6ec704416ecd5ff2bd26213c9bc026bdd19de.1607077340.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman

powerpc: Make setjmp/longjmp signature standard

2020-04-24T06:00:48Z

commit c17eb4dca5a353a9dbbb8ad6934fe57af7165e91 upstream. Declaring setjmp()/longjmp() as taking longs makes the signature non-standard, and makes clang complain. In the past, this has been worked around by adding -ffreestanding to the compile flags. The implementation looks like it only ever propagates the value (in longjmp) or sets it to 1 (in setjmp), and we only call longjmp with integer parameters. This allows removing -ffreestanding from the compilation flags. Fixes: c9029ef9c957 ("powerpc: Avoid clang warnings around setjmp and longjmp") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Clement Courbet Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200330080400.124803-1-courbet@google.com Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

powerpc/xmon: don't access ASDR in VMs

2020-02-14T21:32:09Z

commit c2a20711fc181e7f22ee5c16c28cb9578af84729 upstream. ASDR is HV-privileged and must only be accessed in HV-mode. Fixes a Program Check (0x700) when xmon in a VM dumps SPRs. Fixes: d1e1b351f50f ("powerpc/xmon: Add ISA v3.0 SPRs to SPR dump") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Sukadev Bhattiprolu Reviewed-by: Andrew Donnellan Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200107021633.GB29843@us.ibm.com Signed-off-by: Greg Kroah-Hartman

powerpc: Avoid clang warnings around setjmp and longjmp

2019-12-17T19:39:57Z

[ Upstream commit c9029ef9c95765e7b63c4d9aa780674447db1ec0 ] Commit aea447141c7e ("powerpc: Disable -Wbuiltin-requires-header when setjmp is used") disabled -Wbuiltin-requires-header because of a warning about the setjmp and longjmp declarations. r367387 in clang added another diagnostic around this, complaining that there is no jmp_buf declaration. In file included from ../arch/powerpc/xmon/xmon.c:47: ../arch/powerpc/include/asm/setjmp.h:10:13: error: declaration of built-in function 'setjmp' requires the declaration of the 'jmp_buf' type, commonly provided in the header . [-Werror,-Wincomplete-setjmp-declaration] extern long setjmp(long *); ^ ../arch/powerpc/include/asm/setjmp.h:11:13: error: declaration of built-in function 'longjmp' requires the declaration of the 'jmp_buf' type, commonly provided in the header . [-Werror,-Wincomplete-setjmp-declaration] extern void longjmp(long *, long); ^ 2 errors generated. We are not using the standard library's longjmp/setjmp implementations for obvious reasons; make this clear to clang by using -ffreestanding on these files. Cc: stable@vger.kernel.org # 4.14+ Suggested-by: Segher Boessenkool Reviewed-by: Nick Desaulniers Signed-off-by: Nathan Chancellor Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191119045712.39633-3-natechancellor@gmail.com Signed-off-by: Sasha Levin

powerpc/xmon: fix dump_segments()

2019-12-05T14:37:36Z

[ Upstream commit 32c8c4c621897199e690760c2d57054f8b84b6e6 ] mfsrin() takes segment num from bits 31-28 (IBM bits 0-3). Signed-off-by: Christophe Leroy [mpe: Clarify bit numbering] Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin

powerpc/xmon: Relax frame size for clang

2019-12-01T08:13:51Z

[ Upstream commit 9c87156cce5a63735d1218f0096a65c50a7a32aa ] When building with clang (8 trunk, 7.0 release) the frame size limit is hit: arch/powerpc/xmon/xmon.c:452:12: warning: stack frame size of 2576 bytes in function 'xmon_core' [-Wframe-larger-than=] Some investigation by Naveen indicates this is due to clang saving the addresses to printf format strings on the stack. While this issue is investigated, bump up the frame size limit for xmon when building with clang. Link: https://github.com/ClangBuiltLinux/linux/issues/252 Signed-off-by: Joel Stanley Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin

powerpc/xmon: Check for HV mode when dumping XIVE info from OPAL

2019-10-07T16:55:01Z

[ Upstream commit c3e0dbd7f780a58c4695f1cd8fc8afde80376737 ] Currently, the xmon 'dx' command calls OPAL to dump the XIVE state in the OPAL logs and also outputs some of the fields of the internal XIVE structures in Linux. The OPAL calls can only be done on baremetal (PowerNV) and they crash a pseries machine. Fix by checking the hypervisor feature of the CPU. Signed-off-by: Cédric Le Goater Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190814154754.23682-2-clg@kaod.org Signed-off-by: Sasha Levin

powerpc/xmon: Fix disabling tracing while in xmon

2019-07-31T05:28:53Z

[ Upstream commit aaf06665f7ea3ee9f9754e16c1a507a89f1de5b1 ] Commit ed49f7fd6438d ("powerpc/xmon: Disable tracing when entering xmon") added code to disable recording trace entries while in xmon. The commit introduced a variable 'tracing_enabled' to record if tracing was enabled on xmon entry, and used this to conditionally enable tracing during exit from xmon. However, we are not checking the value of 'fromipi' variable in xmon_core() when setting 'tracing_enabled'. Due to this, when secondary cpus enter xmon, they will see tracing as being disabled already and tracing won't be re-enabled on exit. Fix the same. Fixes: ed49f7fd6438d ("powerpc/xmon: Disable tracing when entering xmon") Signed-off-by: Naveen N. Rao Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin

powerpc/xmon: Fix opcode being uninitialized in print_insn_powerpc

2019-04-05T20:31:30Z

[ Upstream commit e7140639b1de65bba435a6bd772d134901141f86 ] When building with -Wsometimes-uninitialized, Clang warns: arch/powerpc/xmon/ppc-dis.c:157:7: warning: variable 'opcode' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] if (cpu_has_feature(CPU_FTRS_POWER9)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/xmon/ppc-dis.c:167:7: note: uninitialized use occurs here if (opcode == NULL) ^~~~~~ arch/powerpc/xmon/ppc-dis.c:157:3: note: remove the 'if' if its condition is always true if (cpu_has_feature(CPU_FTRS_POWER9)) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/powerpc/xmon/ppc-dis.c:132:38: note: initialize the variable 'opcode' to silence this warning const struct powerpc_opcode *opcode; ^ = NULL 1 warning generated. This warning seems to make no sense on the surface because opcode is set to NULL right below this statement. However, there is a comma instead of semicolon to end the dialect assignment, meaning that the opcode assignment only happens in the if statement. Properly terminate that line so that Clang no longer warns. Fixes: 5b102782c7f4 ("powerpc/xmon: Enable disassembly files (compilation changes)") Signed-off-by: Nathan Chancellor Reviewed-by: Nick Desaulniers Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin

powerpc/xmon: Fix invocation inside lock region

2019-01-26T08:37:02Z

[ Upstream commit 8d4a862276a9c30a269d368d324fb56529e6d5fd ] Currently xmon needs to get devtree_lock (through rtas_token()) during its invocation (at crash time). If there is a crash while devtree_lock is being held, then xmon tries to get the lock but spins forever and never get into the interactive debugger, as in the following case: int *ptr = NULL; raw_spin_lock_irqsave(&devtree_lock, flags); *ptr = 0xdeadbeef; This patch avoids calling rtas_token(), thus trying to get the same lock, at crash time. This new mechanism proposes getting the token at initialization time (xmon_init()) and just consuming it at crash time. This would allow xmon to be possible invoked independent of devtree_lock being held or not. Signed-off-by: Breno Leitao Reviewed-by: Thiago Jung Bauermann Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin