| Message ID | 20241203-add-m68k-tracing-support-v2-2-77302097a9f4@yoseli.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add basic tracing support for m68k | expand |
Jean-Michel, good work on adding On 4/12/24 06:21, Jean-Michel Hautbois wrote: > In order to use tracing, implement a basic arch_stack_walk() based on > the one in PowerPC. > Tested on a M54418 coldfire. > > Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org> > --- > arch/m68k/Kconfig | 6 ++++ > arch/m68k/kernel/Makefile | 1 + > arch/m68k/kernel/stacktrace.c | 70 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 77 insertions(+) > > diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig > index 793ab1e2762609725bbf793f6dffecfa3ecfff0f..6ba3238ba2c68acaf5974396739e629b09eee3ca 100644 > --- a/arch/m68k/Kconfig > +++ b/arch/m68k/Kconfig > @@ -40,6 +40,8 @@ config M68K > select UACCESS_MEMCPY if !MMU > select ZONE_DMA > select TRACE_IRQFLAGS_SUPPORT > + select ARCH_STACKWALK > + select ARCH_WANT_FRAME_POINTERS How much does that add to kernel size? It's only needed for debugging so some folks may prefer to save a little on code size (not to mention the extra frame pointer save on each call) ... Cheers, Michael > > config CPU_BIG_ENDIAN > def_bool y > @@ -106,6 +108,10 @@ config BOOTINFO_PROC > Say Y to export the bootinfo used to boot the kernel in a > "bootinfo" file in procfs. This is useful with kexec. > > +config STACKTRACE_SUPPORT > + bool > + default y > + Any reason why you can't place the two 'select' statements in this conditional? > menu "Platform setup" > > source "arch/m68k/Kconfig.cpu" > diff --git a/arch/m68k/kernel/Makefile b/arch/m68k/kernel/Makefile > index 6c732ed3998b714a4842ee29c977550a61979779..cb02bcfe04c6b265fa97db9237395a262e649989 100644 > --- a/arch/m68k/kernel/Makefile > +++ b/arch/m68k/kernel/Makefile > @@ -23,3 +23,4 @@ obj-$(CONFIG_UBOOT) += uboot.o > > obj-$(CONFIG_EARLY_PRINTK) += early_printk.o > > +obj-y += stacktrace.o > diff --git a/arch/m68k/kernel/stacktrace.c b/arch/m68k/kernel/stacktrace.c > new file mode 100644 > index 0000000000000000000000000000000000000000..4c2fb6b0cf675ee5a3a21393a50603fea98a1b03 > --- /dev/null > +++ b/arch/m68k/kernel/stacktrace.c > @@ -0,0 +1,70 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +/* > + * Stack trace utility functions etc. > + * > + * Copyright 2024 Jean-Michel Hautbois, Yoseli SAS. > + */ > + > +#include <asm/current.h> > +#include <asm/ptrace.h> > +#include <linux/sched.h> > +#include <linux/sched/task_stack.h> > +#include <linux/stacktrace.h> > + > +static inline unsigned long current_stack_frame(void) > +{ > + unsigned long sp; > + > + asm volatile("movl %%fp, %0" : "=r"(sp)); > + return sp; > +} > + > +static inline int validate_sp(unsigned long sp, struct task_struct *task) > +{ > + unsigned long stack_start, stack_end; > + > + if (task == current) > + stack_start = (unsigned long)task_stack_page(task); > + else > + stack_start = (unsigned long)task->thread.esp0; > + > + stack_end = stack_start + THREAD_SIZE; > + > + if (sp < stack_start || sp >= stack_end) > + return 0; > + > + return 1; > +} > + > +void __no_sanitize_address arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, > + struct task_struct *task, struct pt_regs *regs) > +{ > + unsigned long sp; > + > + if (regs && !consume_entry(cookie, regs->pc)) > + return; > + > + if (regs) > + sp = (unsigned long) regs; > + else if (task == current) > + sp = current_stack_frame(); > + else > + sp = task->thread.ksp; > + > + for (;;) { > + unsigned long *stack = (unsigned long *) sp; > + unsigned long newsp, ip; > + > + if (!validate_sp(sp, task)) > + return; > + > + newsp = stack[0]; > + ip = stack[1]; > + > + if (!consume_entry(cookie, ip)) > + return; > + > + sp = newsp; > + } > +} >
Hi Michael, On 03/12/2024 19:21, Michael Schmitz wrote: > Jean-Michel, > > good work on adding Thanks ^_^ > On 4/12/24 06:21, Jean-Michel Hautbois wrote: >> In order to use tracing, implement a basic arch_stack_walk() based on >> the one in PowerPC. >> Tested on a M54418 coldfire. >> >> Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org> >> --- >> arch/m68k/Kconfig | 6 ++++ >> arch/m68k/kernel/Makefile | 1 + >> arch/m68k/kernel/stacktrace.c | 70 +++++++++++++++++++++++++++++++++ >> ++++++++++ >> 3 files changed, 77 insertions(+) >> >> diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig >> index >> 793ab1e2762609725bbf793f6dffecfa3ecfff0f..6ba3238ba2c68acaf5974396739e629b09eee3ca 100644 >> --- a/arch/m68k/Kconfig >> +++ b/arch/m68k/Kconfig >> @@ -40,6 +40,8 @@ config M68K >> select UACCESS_MEMCPY if !MMU >> select ZONE_DMA >> select TRACE_IRQFLAGS_SUPPORT >> + select ARCH_STACKWALK >> + select ARCH_WANT_FRAME_POINTERS > > How much does that add to kernel size? It's only needed for debugging so > some folks may prefer to save a little on code size (not to mention the > extra frame pointer save on each call) ... Oh yeah, I have such a fast (ah ah) cpu that I forget others may not. I have not measure the size it adds. > > Cheers, > > Michael > > >> config CPU_BIG_ENDIAN >> def_bool y >> @@ -106,6 +108,10 @@ config BOOTINFO_PROC >> Say Y to export the bootinfo used to boot the kernel in a >> "bootinfo" file in procfs. This is useful with kexec. >> +config STACKTRACE_SUPPORT >> + bool >> + default y >> + > Any reason why you can't place the two 'select' statements in this > conditional? Absolutely not, I will add those here and condition the stacktrace to coldfire (or even M5441x ?) ? >> menu "Platform setup" >> source "arch/m68k/Kconfig.cpu" >> diff --git a/arch/m68k/kernel/Makefile b/arch/m68k/kernel/Makefile >> index >> 6c732ed3998b714a4842ee29c977550a61979779..cb02bcfe04c6b265fa97db9237395a262e649989 100644 >> --- a/arch/m68k/kernel/Makefile >> +++ b/arch/m68k/kernel/Makefile >> @@ -23,3 +23,4 @@ obj-$(CONFIG_UBOOT) += uboot.o >> obj-$(CONFIG_EARLY_PRINTK) += early_printk.o >> +obj-y += stacktrace.o >> diff --git a/arch/m68k/kernel/stacktrace.c b/arch/m68k/kernel/ >> stacktrace.c >> new file mode 100644 >> index >> 0000000000000000000000000000000000000000..4c2fb6b0cf675ee5a3a21393a50603fea98a1b03 >> --- /dev/null >> +++ b/arch/m68k/kernel/stacktrace.c >> @@ -0,0 +1,70 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> + >> +/* >> + * Stack trace utility functions etc. >> + * >> + * Copyright 2024 Jean-Michel Hautbois, Yoseli SAS. >> + */ >> + >> +#include <asm/current.h> >> +#include <asm/ptrace.h> >> +#include <linux/sched.h> >> +#include <linux/sched/task_stack.h> >> +#include <linux/stacktrace.h> >> + >> +static inline unsigned long current_stack_frame(void) >> +{ >> + unsigned long sp; >> + >> + asm volatile("movl %%fp, %0" : "=r"(sp)); >> + return sp; >> +} >> + >> +static inline int validate_sp(unsigned long sp, struct task_struct >> *task) >> +{ >> + unsigned long stack_start, stack_end; >> + >> + if (task == current) >> + stack_start = (unsigned long)task_stack_page(task); >> + else >> + stack_start = (unsigned long)task->thread.esp0; >> + >> + stack_end = stack_start + THREAD_SIZE; >> + >> + if (sp < stack_start || sp >= stack_end) >> + return 0; >> + >> + return 1; >> +} >> + >> +void __no_sanitize_address arch_stack_walk(stack_trace_consume_fn >> consume_entry, void *cookie, >> + struct task_struct *task, struct pt_regs *regs) >> +{ >> + unsigned long sp; >> + >> + if (regs && !consume_entry(cookie, regs->pc)) >> + return; >> + >> + if (regs) >> + sp = (unsigned long) regs; >> + else if (task == current) >> + sp = current_stack_frame(); >> + else >> + sp = task->thread.ksp; >> + >> + for (;;) { >> + unsigned long *stack = (unsigned long *) sp; >> + unsigned long newsp, ip; >> + >> + if (!validate_sp(sp, task)) >> + return; >> + >> + newsp = stack[0]; >> + ip = stack[1]; >> + >> + if (!consume_entry(cookie, ip)) >> + return; >> + >> + sp = newsp; >> + } >> +} >>
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig index 793ab1e2762609725bbf793f6dffecfa3ecfff0f..6ba3238ba2c68acaf5974396739e629b09eee3ca 100644 --- a/arch/m68k/Kconfig +++ b/arch/m68k/Kconfig @@ -40,6 +40,8 @@ config M68K select UACCESS_MEMCPY if !MMU select ZONE_DMA select TRACE_IRQFLAGS_SUPPORT + select ARCH_STACKWALK + select ARCH_WANT_FRAME_POINTERS config CPU_BIG_ENDIAN def_bool y @@ -106,6 +108,10 @@ config BOOTINFO_PROC Say Y to export the bootinfo used to boot the kernel in a "bootinfo" file in procfs. This is useful with kexec. +config STACKTRACE_SUPPORT + bool + default y + menu "Platform setup" source "arch/m68k/Kconfig.cpu" diff --git a/arch/m68k/kernel/Makefile b/arch/m68k/kernel/Makefile index 6c732ed3998b714a4842ee29c977550a61979779..cb02bcfe04c6b265fa97db9237395a262e649989 100644 --- a/arch/m68k/kernel/Makefile +++ b/arch/m68k/kernel/Makefile @@ -23,3 +23,4 @@ obj-$(CONFIG_UBOOT) += uboot.o obj-$(CONFIG_EARLY_PRINTK) += early_printk.o +obj-y += stacktrace.o diff --git a/arch/m68k/kernel/stacktrace.c b/arch/m68k/kernel/stacktrace.c new file mode 100644 index 0000000000000000000000000000000000000000..4c2fb6b0cf675ee5a3a21393a50603fea98a1b03 --- /dev/null +++ b/arch/m68k/kernel/stacktrace.c @@ -0,0 +1,70 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Stack trace utility functions etc. + * + * Copyright 2024 Jean-Michel Hautbois, Yoseli SAS. + */ + +#include <asm/current.h> +#include <asm/ptrace.h> +#include <linux/sched.h> +#include <linux/sched/task_stack.h> +#include <linux/stacktrace.h> + +static inline unsigned long current_stack_frame(void) +{ + unsigned long sp; + + asm volatile("movl %%fp, %0" : "=r"(sp)); + return sp; +} + +static inline int validate_sp(unsigned long sp, struct task_struct *task) +{ + unsigned long stack_start, stack_end; + + if (task == current) + stack_start = (unsigned long)task_stack_page(task); + else + stack_start = (unsigned long)task->thread.esp0; + + stack_end = stack_start + THREAD_SIZE; + + if (sp < stack_start || sp >= stack_end) + return 0; + + return 1; +} + +void __no_sanitize_address arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, + struct task_struct *task, struct pt_regs *regs) +{ + unsigned long sp; + + if (regs && !consume_entry(cookie, regs->pc)) + return; + + if (regs) + sp = (unsigned long) regs; + else if (task == current) + sp = current_stack_frame(); + else + sp = task->thread.ksp; + + for (;;) { + unsigned long *stack = (unsigned long *) sp; + unsigned long newsp, ip; + + if (!validate_sp(sp, task)) + return; + + newsp = stack[0]; + ip = stack[1]; + + if (!consume_entry(cookie, ip)) + return; + + sp = newsp; + } +}
In order to use tracing, implement a basic arch_stack_walk() based on the one in PowerPC. Tested on a M54418 coldfire. Signed-off-by: Jean-Michel Hautbois <jeanmichel.hautbois@yoseli.org> --- arch/m68k/Kconfig | 6 ++++ arch/m68k/kernel/Makefile | 1 + arch/m68k/kernel/stacktrace.c | 70 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 77 insertions(+)