kernel.git/tools/perf/util/perf_regs.h, branch master

perf regs: Remove __weak attributive arch_sdt_arg_parse_op() function

2026-02-06T15:16:12Z

In line with the previous patch, the __weak arch_sdt_arg_parse_op() function is removed. Architectural-specific implementations in the arch/ directory are now converted into sub-functions within the util/perf-regs-arch/ directory. The perf_sdt_arg_parse_op() function will call these sub-functions based on the EM_HOST. This change enables cross-architecture calls to arch_sdt_arg_parse_op(). No functional changes are intended. Suggested-by: Ian Rogers Reviewed-by: Ian Rogers Signed-off-by: Dapeng Mi Cc: Adrian Hunter Cc: Albert Ou Cc: Alexander Shishkin Cc: Alexandre Ghiti Cc: Guo Ren Cc: Ingo Molnar Cc: James Clark Cc: John Garry Cc: Mike Leach Cc: Namhyung Kim Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Thomas Falcon Cc: Will Deacon Cc: Xudong Hao Cc: Zide Chen [ Fixed up somme fuzz with powerpc and x86 Build files wrt removing perf_regs.o ] Signed-off-by: Arnaldo Carvalho de Melo

perf regs: Remove weak attributive archxxx_reg_mask() functions

2026-02-06T15:16:09Z

Currently, some architecture-specific perf-regs functions, such as arch__intr_reg_mask() and arch__user_reg_mask(), are defined with the __weak attribute. This approach ensures that only functions matching the architecture of the build/run host are compiled and executed, reducing build time and binary size. However, this __weak attribute restricts these functions to be called only on the same architecture, preventing cross-architecture functionality. For example, a perf.data file captured on x86 cannot be parsed on an ARM platform. To address this limitation, this patch removes the __weak attribute from these perf-regs functions. The architecture-specific code is moved from the arch/ directory to the util/perf-regs-arch/ directory. The appropriate architectural functions are then called based on the EM_HOST. No functional changes are intended. Suggested-by: Ian Rogers Reviewed-by: Ian Rogers Signed-off-by: Dapeng Mi Cc: Adrian Hunter Cc: Albert Ou Cc: Alexander Shishkin Cc: Alexandre Ghiti Cc: Guo Ren Cc: Ingo Molnar Cc: James Clark Cc: John Garry Cc: Mike Leach Cc: Namhyung Kim Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Thomas Falcon Cc: Will Deacon Cc: Xudong Hao Cc: Zide Chen [ Fixed up somme fuzz with s390 and riscv Build files wrt removing perf_regs.o ] Signed-off-by: Arnaldo Carvalho de Melo

perf perf_regs: Accurately compute register names for CSKY

2026-01-26T21:31:16Z

CSKY needs the e_flags to determine the ABI level and know whether additional registers are encoded or not. Wire this up now that the e_flags for a thread can be determined. Signed-off-by: Ian Rogers Cc: Aditya Bodkhe Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Athira Rajeev Cc: Chun-Tse Shao Cc: Guo Ren Cc: Howard Chu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Sergei Trofimovich Cc: Shimin Guo Cc: Stephen Brennan Cc: Swapnil Sapkal Cc: Tianyou Li [ Conditionally define EF_CSKY_ABIMASK and EF_CSKY_ABIV2 for older distros ] Signed-off-by: Arnaldo Carvalho de Melo

perf regs: Refactor use of arch__sample_reg_masks() to perf_reg_name()

2026-01-23T19:58:39Z

arch__sample_reg_masks isn't supported on ARM(32), csky, loongarch, MIPS, RISC-V and s390. The table returned by the function just has the name of a register paired with the corresponding sample_regs_user mask value. For a given perf register we can compute the name with perf_reg_name and the mask is just 1 left-shifted by the perf register number. Change __parse_regs to use this method for finding registers rather than arch__sample_reg_masks, thereby adding __parse_regs support for ARM(32), csky, loongarch, MIPS, RISC-V and s390. As arch__sample_reg_masks is then unused, remove the now unneeded declarations. Signed-off-by: Ian Rogers Tested-by: Thomas Richter Cc: Aditya Bodkhe Cc: Adrian Hunter Cc: Albert Ou Cc: Alexandre Ghiti Cc: Andi Kleen Cc: Athira Rajeev Cc: Chun-Tse Shao Cc: Dapeng Mi Cc: Dmitriy Vyukov Cc: Dr. David Alan Gilbert Cc: Guo Ren Cc: Haibo Xu Cc: Howard Chu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Krzysztof Łopatowski Cc: Leo Yan Cc: Namhyung Kim Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Sergei Trofimovich Cc: Shimin Guo Cc: Stephen Brennan Cc: Thomas Falcon Cc: Will Deacon Signed-off-by: Arnaldo Carvalho de Melo

perf perf_regs: Switch from arch string to int e_machine

2026-01-20T18:43:04Z

The arch string requires multiple strcmp to identify things like the IP and SP. Switch to passing in an e_machine that in the bulk of cases is computed using a current thread load. The e_machine also allows identification of 32-bit vs 64-bit processes. Signed-off-by: Ian Rogers Cc: Aditya Bodkhe Cc: Adrian Hunter Cc: Albert Ou Cc: Alexandre Ghiti Cc: Andi Kleen Cc: Athira Rajeev Cc: Chun-Tse Shao Cc: Dmitriy Vyukov Cc: Dr. David Alan Gilbert Cc: Guo Ren Cc: Haibo Xu Cc: Howard Chu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Krzysztof Łopatowski Cc: Leo Yan Cc: Mark Wielaard Cc: Namhyung Kim Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Sergei Trofimovich Cc: Shimin Guo Cc: Stephen Brennan Cc: Thomas Falcon Cc: Will Deacon [ Include dwarf-regs.h to get conditional defines for EM_CSKY and EM_LOONGARCH, not available in old distros ] Signed-off-by: Arnaldo Carvalho de Melo

perf parse-regs: Introduce a weak function arch__sample_reg_masks()

2024-02-15T21:48:36Z

Every architecture can provide a register list for sampling. If an architecture doesn't support register sampling, it won't define the data structure 'sample_reg_masks'. Consequently, any code using this structure must be protected by the macro 'HAVE_PERF_REGS_SUPPORT'. This patch defines a weak function, arch__sample_reg_masks(), which will be replaced by an architecture-defined function for returning the architecture's register list. With this refactoring, the function always exists, the condition checking for 'HAVE_PERF_REGS_SUPPORT' is not needed anymore, so remove it. Signed-off-by: Leo Yan Reviewed-by: Ian Rogers Cc: James Clark Cc: Palmer Dabbelt Cc: Albert Ou Cc: Huacai Chen Cc: Guo Ren Cc: Will Deacon Cc: Mike Leach Cc: Kan Liang Cc: Ming Wang Cc: John Garry Cc: Paul Walmsley Cc: linux-csky@vger.kernel.org Cc: linux-riscv@lists.infradead.org Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240214113947.240957-4-leo.yan@linux.dev

perf parse-regs: Always build perf register functions

2024-02-15T21:48:20Z

Currently, the macro HAVE_PERF_REGS_SUPPORT is used as a switch to turn on or turn off the code of perf registers. If any architecture cannot support perf register, it disables the perf register parsing, for both the native parsing and cross parsing for other architectures. To support both the native parsing and cross parsing, the tool should always build the perf regs functions. Thus, this patch removes HAVE_PERF_REGS_SUPPORT from the perf regs files. Signed-off-by: Leo Yan Reviewed-by: Ian Rogers Cc: James Clark Cc: Palmer Dabbelt Cc: Albert Ou Cc: Huacai Chen Cc: Guo Ren Cc: Will Deacon Cc: Mike Leach Cc: Kan Liang Cc: Ming Wang Cc: John Garry Cc: Paul Walmsley Cc: linux-csky@vger.kernel.org Cc: linux-riscv@lists.infradead.org Signed-off-by: Namhyung Kim Link: https://lore.kernel.org/r/20240214113947.240957-3-leo.yan@linux.dev

perf parse-regs: Move out arch specific header from util/perf_regs.h

2023-08-16T11:52:45Z

util/perf_regs.h includes another perf_regs.h: #include Here it includes architecture specific header, for example, if we build arm64 target, the header tools/perf/arch/arm64/include/perf_regs.h is included. We use this implicit way to include architecture specific header, which is not directive; furthermore, util/perf_regs.c is coupled with the architecture specific definitions. This patch moves out arch specific header from util/perf_regs.h for generalizing the 'util' folder, as a result, the source files in 'arch' folder explicitly include architecture's perf_regs.h. Signed-off-by: Leo Yan Acked-by: Ian Rogers Cc: Adrian Hunter Cc: Albert Ou Cc: Alexander Shishkin Cc: Eric Lin Cc: Fangrui Song Cc: Guo Ren Cc: Huacai Chen Cc: Ingo Molnar Cc: Ivan Babrou Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Kan Liang Cc: Mark Rutland Cc: Mike Leach Cc: Ming Wang Cc: Namhyung Kim Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Sandipan Das Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Cc: linux-csky@vger.kernel.org Cc: linux-riscv@lists.infradead.org Link: https://lore.kernel.org/r/20230606014559.21783-7-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo

perf parse-regs: Remove PERF_REGS_{MAX|MASK} from common code

2023-08-16T11:49:10Z

The macros PERF_REGS_MAX and PERF_REGS_MASK are architecture specific, let's remove them from the common file util/perf_regs.c. As a side effect, the weak functions arch__intr_reg_mask() and arch__user_reg_mask() just return zeros, every arch defines its own functions in the 'arch' folder for returning right values. Note, we don't need to return intr/user register masks dynamically, this is because these two functions are invoked during recording phase but not decoding phase, they are always invoked on the native environment, thus we don't need to parse them dynamically. Signed-off-by: Leo Yan Acked-by: Ian Rogers Cc: Adrian Hunter Cc: Albert Ou Cc: Alexander Shishkin Cc: Eric Lin Cc: Fangrui Song Cc: Guo Ren Cc: Huacai Chen Cc: Ingo Molnar Cc: Ivan Babrou Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Kan Liang Cc: Mark Rutland Cc: Mike Leach Cc: Ming Wang Cc: Namhyung Kim Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Sandipan Das Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Cc: linux-csky@vger.kernel.org Cc: linux-riscv@lists.infradead.org Link: https://lore.kernel.org/r/20230606014559.21783-6-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo

perf parse-regs: Introduce functions perf_arch_reg_{ip|sp}()

2023-08-16T11:46:45Z

The current code uses macros PERF_REG_IP and PERF_REG_SP for parsing registers and we build perf with these macros statically, which means it only can correctly analyze CPU registers for the native architecture and fails to support cross analysis (e.g. we build perf on x86 and cannot analyze Arm64's registers). We need to generalize util/perf_regs.c for support multi architectures, as a first step, this commit introduces new functions perf_arch_reg_ip() and perf_arch_reg_sp(), these two functions dynamically return IP and SP register index respectively according to the parameter "arch". Every architecture has its own functions (like __perf_reg_ip_arm64 and __perf_reg_sp_arm64), these architecture specific functions are defined in each arch source file under folder util/perf-regs-arch; at the end all of them are built into the tool for cross analysis. Committer notes: Make DWARF_MINIMAL_REGS() an inline function, so that we can use the __maybe_unused attribute for the 'arch' parameter, as this will avoid a build failure when that variable is unused in the callers. That happens when building on unsupported architectures, the ones without HAVE_PERF_REGS_SUPPORT defined. Signed-off-by: Leo Yan Acked-by: Ian Rogers Cc: Adrian Hunter Cc: Albert Ou Cc: Alexander Shishkin Cc: Eric Lin Cc: Fangrui Song Cc: Guo Ren Cc: Huacai Chen Cc: Ingo Molnar Cc: Ivan Babrou Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Kan Liang Cc: Mark Rutland Cc: Mike Leach Cc: Ming Wang Cc: Namhyung Kim Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Sandipan Das Cc: Will Deacon Cc: linux-arm-kernel@lists.infradead.org Cc: linux-csky@vger.kernel.org Cc: linux-riscv@lists.infradead.org Link: https://lore.kernel.org/r/20230606014559.21783-3-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo