| Message ID | 20240604034729.841930-1-ruanjinjie@huawei.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] riscv: stacktrace: Add USER_STACKTRACE support | expand |
Gentle ping. On 2024/6/4 11:47, Jinjie Ruan wrote: > Currently, userstacktrace is unsupported for riscv. So use the > perf_callchain_user() code as blueprint to implement the > arch_stack_walk_user() which add userstacktrace support on riscv. > Meanwhile, we can use arch_stack_walk_user() to simplify the implementation > of perf_callchain_user(). > > Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> > Reported-by: kernel test robot <lkp@intel.com> > Closes: https://lore.kernel.org/oe-kbuild-all/202406012109.PDAjXm2i-lkp@intel.com/ > --- > v2: > - Fix the cocci warning, !A || A && B is equivalent to !A || B. > --- > arch/riscv/Kconfig | 1 + > arch/riscv/kernel/perf_callchain.c | 46 ++---------------------------- > arch/riscv/kernel/stacktrace.c | 43 ++++++++++++++++++++++++++++ > 3 files changed, 47 insertions(+), 43 deletions(-) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 0525ee2d63c7..6ed96d935b8f 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -193,6 +193,7 @@ config RISCV > select THREAD_INFO_IN_TASK > select TRACE_IRQFLAGS_SUPPORT > select UACCESS_MEMCPY if !MMU > + select USER_STACKTRACE_SUPPORT > select ZONE_DMA32 if 64BIT > > config CLANG_SUPPORTS_DYNAMIC_FTRACE > diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c > index 3348a61de7d9..c7468af77c66 100644 > --- a/arch/riscv/kernel/perf_callchain.c > +++ b/arch/riscv/kernel/perf_callchain.c > @@ -6,37 +6,9 @@ > > #include <asm/stacktrace.h> > > -/* > - * Get the return address for a single stackframe and return a pointer to the > - * next frame tail. > - */ > -static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry, > - unsigned long fp, unsigned long reg_ra) > +static bool fill_callchain(void *entry, unsigned long pc) > { > - struct stackframe buftail; > - unsigned long ra = 0; > - unsigned long __user *user_frame_tail = > - (unsigned long __user *)(fp - sizeof(struct stackframe)); > - > - /* Check accessibility of one struct frame_tail beyond */ > - if (!access_ok(user_frame_tail, sizeof(buftail))) > - return 0; > - if (__copy_from_user_inatomic(&buftail, user_frame_tail, > - sizeof(buftail))) > - return 0; > - > - if (reg_ra != 0) > - ra = reg_ra; > - else > - ra = buftail.ra; > - > - fp = buftail.fp; > - if (ra != 0) > - perf_callchain_store(entry, ra); > - else > - return 0; > - > - return fp; > + return perf_callchain_store(entry, pc) == 0; > } > > /* > @@ -56,19 +28,7 @@ static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry, > void perf_callchain_user(struct perf_callchain_entry_ctx *entry, > struct pt_regs *regs) > { > - unsigned long fp = 0; > - > - fp = regs->s0; > - perf_callchain_store(entry, regs->epc); > - > - fp = user_backtrace(entry, fp, regs->ra); > - while (fp && !(fp & 0x3) && entry->nr < entry->max_stack) > - fp = user_backtrace(entry, fp, 0); > -} > - > -static bool fill_callchain(void *entry, unsigned long pc) > -{ > - return perf_callchain_store(entry, pc) == 0; > + arch_stack_walk_user(fill_callchain, entry, regs); > } > > void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, > diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c > index 528ec7cc9a62..9685a2baa5d9 100644 > --- a/arch/riscv/kernel/stacktrace.c > +++ b/arch/riscv/kernel/stacktrace.c > @@ -161,3 +161,46 @@ noinline void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie > { > walk_stackframe(task, regs, consume_entry, cookie); > } > + > +/* > + * Get the return address for a single stackframe and return a pointer to the > + * next frame tail. > + */ > +static unsigned long unwind_user_frame(stack_trace_consume_fn consume_entry, > + void *cookie, unsigned long fp, > + unsigned long reg_ra) > +{ > + struct stackframe buftail; > + unsigned long ra = 0; > + unsigned long __user *user_frame_tail = > + (unsigned long __user *)(fp - sizeof(struct stackframe)); > + > + /* Check accessibility of one struct frame_tail beyond */ > + if (!access_ok(user_frame_tail, sizeof(buftail))) > + return 0; > + if (__copy_from_user_inatomic(&buftail, user_frame_tail, > + sizeof(buftail))) > + return 0; > + > + ra = reg_ra ? : buftail.ra; > + > + fp = buftail.fp; > + if (!ra || !consume_entry(cookie, ra)) > + return 0; > + > + return fp; > +} > + > +void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie, > + const struct pt_regs *regs) > +{ > + unsigned long fp = 0; > + > + fp = regs->s0; > + if (!consume_entry(cookie, regs->epc)) > + return; > + > + fp = unwind_user_frame(consume_entry, cookie, fp, regs->ra); > + while (fp && !(fp & 0x3)) > + fp = unwind_user_frame(consume_entry, cookie, fp, 0); > +}
Jinjie Ruan <ruanjinjie@huawei.com> writes: > Currently, userstacktrace is unsupported for riscv. So use the > perf_callchain_user() code as blueprint to implement the > arch_stack_walk_user() which add userstacktrace support on riscv. > Meanwhile, we can use arch_stack_walk_user() to simplify the implementation > of perf_callchain_user(). > > Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> > Reported-by: kernel test robot <lkp@intel.com> > Closes: https://lore.kernel.org/oe-kbuild-all/202406012109.PDAjXm2i-lkp@intel.com/ For future reference: The LTP tags shouldn't be used when you're spinning a new version. > --- > v2: > - Fix the cocci warning, !A || A && B is equivalent to !A || B. > --- > arch/riscv/Kconfig | 1 + > arch/riscv/kernel/perf_callchain.c | 46 ++---------------------------- > arch/riscv/kernel/stacktrace.c | 43 ++++++++++++++++++++++++++++ > 3 files changed, 47 insertions(+), 43 deletions(-) [...] > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 0525ee2d63c7..6ed96d935b8f 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -193,6 +193,7 @@ config RISCV > select THREAD_INFO_IN_TASK > select TRACE_IRQFLAGS_SUPPORT > select UACCESS_MEMCPY if !MMU > + select USER_STACKTRACE_SUPPORT > select ZONE_DMA32 if 64BIT > > config CLANG_SUPPORTS_DYNAMIC_FTRACE > diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c > index 3348a61de7d9..c7468af77c66 100644 > --- a/arch/riscv/kernel/perf_callchain.c > +++ b/arch/riscv/kernel/perf_callchain.c > @@ -6,37 +6,9 @@ > > #include <asm/stacktrace.h> > > -/* > - * Get the return address for a single stackframe and return a pointer to the > - * next frame tail. > - */ > -static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry, > - unsigned long fp, unsigned long reg_ra) > +static bool fill_callchain(void *entry, unsigned long pc) > { > - struct stackframe buftail; > - unsigned long ra = 0; > - unsigned long __user *user_frame_tail = > - (unsigned long __user *)(fp - sizeof(struct stackframe)); > - > - /* Check accessibility of one struct frame_tail beyond */ > - if (!access_ok(user_frame_tail, sizeof(buftail))) > - return 0; > - if (__copy_from_user_inatomic(&buftail, user_frame_tail, > - sizeof(buftail))) > - return 0; > - > - if (reg_ra != 0) > - ra = reg_ra; > - else > - ra = buftail.ra; > - > - fp = buftail.fp; > - if (ra != 0) > - perf_callchain_store(entry, ra); > - else > - return 0; > - > - return fp; > + return perf_callchain_store(entry, pc) == 0; > } > > /* > @@ -56,19 +28,7 @@ static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry, > void perf_callchain_user(struct perf_callchain_entry_ctx *entry, > struct pt_regs *regs) > { > - unsigned long fp = 0; > - > - fp = regs->s0; > - perf_callchain_store(entry, regs->epc); > - > - fp = user_backtrace(entry, fp, regs->ra); > - while (fp && !(fp & 0x3) && entry->nr < entry->max_stack) > - fp = user_backtrace(entry, fp, 0); > -} > - > -static bool fill_callchain(void *entry, unsigned long pc) > -{ > - return perf_callchain_store(entry, pc) == 0; > + arch_stack_walk_user(fill_callchain, entry, regs); > } > > void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, > diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c > index 528ec7cc9a62..9685a2baa5d9 100644 > --- a/arch/riscv/kernel/stacktrace.c > +++ b/arch/riscv/kernel/stacktrace.c > @@ -161,3 +161,46 @@ noinline void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie > { > walk_stackframe(task, regs, consume_entry, cookie); > } > + > +/* > + * Get the return address for a single stackframe and return a pointer to the > + * next frame tail. > + */ > +static unsigned long unwind_user_frame(stack_trace_consume_fn consume_entry, > + void *cookie, unsigned long fp, > + unsigned long reg_ra) > +{ > + struct stackframe buftail; > + unsigned long ra = 0; > + unsigned long __user *user_frame_tail = > + (unsigned long __user *)(fp - sizeof(struct stackframe)); > + > + /* Check accessibility of one struct frame_tail beyond */ > + if (!access_ok(user_frame_tail, sizeof(buftail))) > + return 0; > + if (__copy_from_user_inatomic(&buftail, user_frame_tail, > + sizeof(buftail))) > + return 0; > + > + ra = reg_ra ? : buftail.ra; > + > + fp = buftail.fp; > + if (!ra || !consume_entry(cookie, ra)) > + return 0; > + > + return fp; > +} > + > +void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie, > + const struct pt_regs *regs) > +{ > + unsigned long fp = 0; > + > + fp = regs->s0; > + if (!consume_entry(cookie, regs->epc)) > + return; > + > + fp = unwind_user_frame(consume_entry, cookie, fp, regs->ra); > + while (fp && !(fp & 0x3)) Just an observation that the "entry->nr < entry->max_stack" check was removed in this generalization, but that's OK since it's checked in perf_callchain_store(). Not really part of your change, but shouldn't the check be 0x7 (checking for 16B sp/fp alignment), rather than 0x3? Björn
On 2024/7/3 22:36, Björn Töpel wrote: > Jinjie Ruan <ruanjinjie@huawei.com> writes: > >> Currently, userstacktrace is unsupported for riscv. So use the >> perf_callchain_user() code as blueprint to implement the >> arch_stack_walk_user() which add userstacktrace support on riscv. >> Meanwhile, we can use arch_stack_walk_user() to simplify the implementation >> of perf_callchain_user(). >> >> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> >> Reported-by: kernel test robot <lkp@intel.com> >> Closes: https://lore.kernel.org/oe-kbuild-all/202406012109.PDAjXm2i-lkp@intel.com/ > > For future reference: The LTP tags shouldn't be used when you're > spinning a new version. Thank you! I'll remove it. > >> --- >> v2: >> - Fix the cocci warning, !A || A && B is equivalent to !A || B. >> --- >> arch/riscv/Kconfig | 1 + >> arch/riscv/kernel/perf_callchain.c | 46 ++---------------------------- >> arch/riscv/kernel/stacktrace.c | 43 ++++++++++++++++++++++++++++ >> 3 files changed, 47 insertions(+), 43 deletions(-) > > [...] > >> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig >> index 0525ee2d63c7..6ed96d935b8f 100644 >> --- a/arch/riscv/Kconfig >> +++ b/arch/riscv/Kconfig >> @@ -193,6 +193,7 @@ config RISCV >> select THREAD_INFO_IN_TASK >> select TRACE_IRQFLAGS_SUPPORT >> select UACCESS_MEMCPY if !MMU >> + select USER_STACKTRACE_SUPPORT >> select ZONE_DMA32 if 64BIT >> >> config CLANG_SUPPORTS_DYNAMIC_FTRACE >> diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c >> index 3348a61de7d9..c7468af77c66 100644 >> --- a/arch/riscv/kernel/perf_callchain.c >> +++ b/arch/riscv/kernel/perf_callchain.c >> @@ -6,37 +6,9 @@ >> >> #include <asm/stacktrace.h> >> >> -/* >> - * Get the return address for a single stackframe and return a pointer to the >> - * next frame tail. >> - */ >> -static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry, >> - unsigned long fp, unsigned long reg_ra) >> +static bool fill_callchain(void *entry, unsigned long pc) >> { >> - struct stackframe buftail; >> - unsigned long ra = 0; >> - unsigned long __user *user_frame_tail = >> - (unsigned long __user *)(fp - sizeof(struct stackframe)); >> - >> - /* Check accessibility of one struct frame_tail beyond */ >> - if (!access_ok(user_frame_tail, sizeof(buftail))) >> - return 0; >> - if (__copy_from_user_inatomic(&buftail, user_frame_tail, >> - sizeof(buftail))) >> - return 0; >> - >> - if (reg_ra != 0) >> - ra = reg_ra; >> - else >> - ra = buftail.ra; >> - >> - fp = buftail.fp; >> - if (ra != 0) >> - perf_callchain_store(entry, ra); >> - else >> - return 0; >> - >> - return fp; >> + return perf_callchain_store(entry, pc) == 0; >> } >> >> /* >> @@ -56,19 +28,7 @@ static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry, >> void perf_callchain_user(struct perf_callchain_entry_ctx *entry, >> struct pt_regs *regs) >> { >> - unsigned long fp = 0; >> - >> - fp = regs->s0; >> - perf_callchain_store(entry, regs->epc); >> - >> - fp = user_backtrace(entry, fp, regs->ra); >> - while (fp && !(fp & 0x3) && entry->nr < entry->max_stack) >> - fp = user_backtrace(entry, fp, 0); >> -} >> - >> -static bool fill_callchain(void *entry, unsigned long pc) >> -{ >> - return perf_callchain_store(entry, pc) == 0; >> + arch_stack_walk_user(fill_callchain, entry, regs); >> } >> >> void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, >> diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c >> index 528ec7cc9a62..9685a2baa5d9 100644 >> --- a/arch/riscv/kernel/stacktrace.c >> +++ b/arch/riscv/kernel/stacktrace.c >> @@ -161,3 +161,46 @@ noinline void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie >> { >> walk_stackframe(task, regs, consume_entry, cookie); >> } >> + >> +/* >> + * Get the return address for a single stackframe and return a pointer to the >> + * next frame tail. >> + */ >> +static unsigned long unwind_user_frame(stack_trace_consume_fn consume_entry, >> + void *cookie, unsigned long fp, >> + unsigned long reg_ra) >> +{ >> + struct stackframe buftail; >> + unsigned long ra = 0; >> + unsigned long __user *user_frame_tail = >> + (unsigned long __user *)(fp - sizeof(struct stackframe)); >> + >> + /* Check accessibility of one struct frame_tail beyond */ >> + if (!access_ok(user_frame_tail, sizeof(buftail))) >> + return 0; >> + if (__copy_from_user_inatomic(&buftail, user_frame_tail, >> + sizeof(buftail))) >> + return 0; >> + >> + ra = reg_ra ? : buftail.ra; >> + >> + fp = buftail.fp; >> + if (!ra || !consume_entry(cookie, ra)) >> + return 0; >> + >> + return fp; >> +} >> + >> +void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie, >> + const struct pt_regs *regs) >> +{ >> + unsigned long fp = 0; >> + >> + fp = regs->s0; >> + if (!consume_entry(cookie, regs->epc)) >> + return; >> + >> + fp = unwind_user_frame(consume_entry, cookie, fp, regs->ra); >> + while (fp && !(fp & 0x3)) > > Just an observation that the "entry->nr < entry->max_stack" check was > removed in this generalization, but that's OK since it's checked in > perf_callchain_store(). Yes, the checked is not necessary, because perf_callchain_store() check "entry->nr < entry->max_stack" Also the caller function stack_trace_save_user() registers the consume_entry callback "stack_trace_consume_entry" for saving user stack traces into a storage array, in which entry->nr against entry->max_stack is put. > > Not really part of your change, but shouldn't the check be 0x7 (checking > for 16B sp/fp alignment), rather than 0x3? You are right! From the below "RISCV Calling Convention" : "In the standard RISC-V calling convention, the stack grows downward and the stack pointer is always kept 16-byte aligned" So the sp should be 16-byte aligned, and the "PT_SIZE_ON_STACK" is also 16-byte aligned, so I think the fp is also 16-byte aligned. Link: https://riscv.org/wp-content/uploads/2015/01/riscv-calling.pdf > > > Björn > >
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 0525ee2d63c7..6ed96d935b8f 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -193,6 +193,7 @@ config RISCV select THREAD_INFO_IN_TASK select TRACE_IRQFLAGS_SUPPORT select UACCESS_MEMCPY if !MMU + select USER_STACKTRACE_SUPPORT select ZONE_DMA32 if 64BIT config CLANG_SUPPORTS_DYNAMIC_FTRACE diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c index 3348a61de7d9..c7468af77c66 100644 --- a/arch/riscv/kernel/perf_callchain.c +++ b/arch/riscv/kernel/perf_callchain.c @@ -6,37 +6,9 @@ #include <asm/stacktrace.h> -/* - * Get the return address for a single stackframe and return a pointer to the - * next frame tail. - */ -static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry, - unsigned long fp, unsigned long reg_ra) +static bool fill_callchain(void *entry, unsigned long pc) { - struct stackframe buftail; - unsigned long ra = 0; - unsigned long __user *user_frame_tail = - (unsigned long __user *)(fp - sizeof(struct stackframe)); - - /* Check accessibility of one struct frame_tail beyond */ - if (!access_ok(user_frame_tail, sizeof(buftail))) - return 0; - if (__copy_from_user_inatomic(&buftail, user_frame_tail, - sizeof(buftail))) - return 0; - - if (reg_ra != 0) - ra = reg_ra; - else - ra = buftail.ra; - - fp = buftail.fp; - if (ra != 0) - perf_callchain_store(entry, ra); - else - return 0; - - return fp; + return perf_callchain_store(entry, pc) == 0; } /* @@ -56,19 +28,7 @@ static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry, void perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - unsigned long fp = 0; - - fp = regs->s0; - perf_callchain_store(entry, regs->epc); - - fp = user_backtrace(entry, fp, regs->ra); - while (fp && !(fp & 0x3) && entry->nr < entry->max_stack) - fp = user_backtrace(entry, fp, 0); -} - -static bool fill_callchain(void *entry, unsigned long pc) -{ - return perf_callchain_store(entry, pc) == 0; + arch_stack_walk_user(fill_callchain, entry, regs); } void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c index 528ec7cc9a62..9685a2baa5d9 100644 --- a/arch/riscv/kernel/stacktrace.c +++ b/arch/riscv/kernel/stacktrace.c @@ -161,3 +161,46 @@ noinline void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie { walk_stackframe(task, regs, consume_entry, cookie); } + +/* + * Get the return address for a single stackframe and return a pointer to the + * next frame tail. + */ +static unsigned long unwind_user_frame(stack_trace_consume_fn consume_entry, + void *cookie, unsigned long fp, + unsigned long reg_ra) +{ + struct stackframe buftail; + unsigned long ra = 0; + unsigned long __user *user_frame_tail = + (unsigned long __user *)(fp - sizeof(struct stackframe)); + + /* Check accessibility of one struct frame_tail beyond */ + if (!access_ok(user_frame_tail, sizeof(buftail))) + return 0; + if (__copy_from_user_inatomic(&buftail, user_frame_tail, + sizeof(buftail))) + return 0; + + ra = reg_ra ? : buftail.ra; + + fp = buftail.fp; + if (!ra || !consume_entry(cookie, ra)) + return 0; + + return fp; +} + +void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie, + const struct pt_regs *regs) +{ + unsigned long fp = 0; + + fp = regs->s0; + if (!consume_entry(cookie, regs->epc)) + return; + + fp = unwind_user_frame(consume_entry, cookie, fp, regs->ra); + while (fp && !(fp & 0x3)) + fp = unwind_user_frame(consume_entry, cookie, fp, 0); +}
Currently, userstacktrace is unsupported for riscv. So use the perf_callchain_user() code as blueprint to implement the arch_stack_walk_user() which add userstacktrace support on riscv. Meanwhile, we can use arch_stack_walk_user() to simplify the implementation of perf_callchain_user(). Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202406012109.PDAjXm2i-lkp@intel.com/ --- v2: - Fix the cocci warning, !A || A && B is equivalent to !A || B. --- arch/riscv/Kconfig | 1 + arch/riscv/kernel/perf_callchain.c | 46 ++---------------------------- arch/riscv/kernel/stacktrace.c | 43 ++++++++++++++++++++++++++++ 3 files changed, 47 insertions(+), 43 deletions(-)