On Tue, May 5, 2020 at 10:43 PM Xu, Yanfei <yanfei...@windriver.com> wrote:
>
> No, you didn't miss any things. I just know that the patches are
> generated from your scripts. And I will resend the patch against
> linux-yocto.
>
ok!
Thanks for the follow up.
It is ok to send things this way if required .. I just was thinking I
had missed something.
I'll wait for v2 for the merge.
Bruce
> Yanfei
>
> On 5/2/20 11:19 PM, Bruce Ashfield wrote:
> > Did I miss applying this to the kernel-cache previously ? or did
> > I miss a patch against the linux-yocto repo itself ?
> >
> > The reason I ask, is that it is awkward to apply patches like this
> > to the tree.
> >
> > If you send the patch against linux-yocto, I'll apply it and then
> > commit the change to the kernel-cache via my scripts.
> >
> > Bruce
> >
> > In message: [linux-yocto][yocto-kernel-cache][master yocto-5.4][PATCH]
> > arm64/perf: fix backtrace for AAPCS with FP enabled
> > on 27/04/2020 yanfei...@windriver.com wrote:
> >
> >> From: Yanfei Xu <yanfei...@windriver.com>
> >>
> >> This change is for arm64 platform compat mode.
> >>
> >> ------[cut here: not apply patch]--------
> >> Samples: 119K of event 'cycles'
> >> Event count (approx.): 114092698680
> >>
> >> Children Self Command Shared Object Symbol
> >> ........ ........ ......... ..................
> >>
> >> 99.85% 0.00% perf-test [unknown] [.]
> >> 0x00000000ff80f4ec
> >> |
> >> ---0xff80f4ec
> >> |
> >> |--37.68%--__aeabi_idivmod
> >> |
> >> |--25.35%--calculate_meaning_of_life
> >> |
> >> |--20.06%--____aeabi_idivmod_from_thumb
> >> |
> >> |--7.25%--0
> >> | |
> >> | |--1.76%--0xf543df9c
> >> | | __gettimeofday
> >>
> >> ------[cut here: apply patch]------------
> >> Samples: 114K of event 'cycles'
> >> Event count (approx.): 109799966925
> >>
> >> Children Self Command Shared Object Symbol
> >> ........ ........ ......... ..................
> >>
> >> 99.91% 0.00% perf-test perf-test [.] main
> >> |
> >> ---main
> >> |
> >> |--57.49%--pthread_create@@GLIBC_2.4
> >> | |
> >> | --57.44%--0xf7cf2f88
> >> | |
> >> | |--20.16%--__aeabi_idivmod
> >> | |
> >> |
> >> |--13.79%--calculate_meaning_of_life
> >> | |
> >> |
> >> |--10.89%--____aeabi_idivmod_from_thumb
> >> | |
> >> | |--8.99%--current_timestamp
> >> | | |
> >> | | --8.98%--__gettimeofday
> >>
> >> 1/1 [
> >> Author: Fang Jia
> >> Email: fang....@windriver.com
> >> Subject: arm64/perf: fix backtrace for AAPCS with FP enabled
> >> Date: Fri, 28 Dec 2018 16:28:34 +0800
> >>
> >> This change is for arm64 platform compat mode.
> >> The change for arm32 platform has been included in this commit "perf:
> >> fix backtrace for AAPCS with FP enabled".
> >>
> >> This change replaces code designed for the obsolete ARM APCS ABI, which
> >> causes failures of the perf backtrace logic unless the gcc option
> >> -mapcs-frame is used to build all binaries on the platform. This
> >> obsolete gcc option forces the compiler to include the stack pointer
> >> along with the frame pointer and link register in the stack frame
> >> for each funciton call. The current AAPCS ABI document, doesn't
> >> explicitly describe the frame structure when the gcc frame pointer
> >> option, -fno-omit-frame-pointer, is enabled. However, with this option
> >> enabled, examination of the emitted prologue instructions shows that
> >> 1) R11 is used as the frame pointer,
> >> 2) only the R11 and LR are saved onto the stack, not the stack pointer,
> >> 3) after this prologue setup, the frame pointer, R11 points to the
> >> saved location of LR on the stack.
> >>
> >> The use of unsigned int arithmetic in the commit is required since
> >> the gcc emitted pointer arithmetic uses 8-byte pointer sizes, which are
> >> incorrect addresses for the 4-byte stack address size.
> >>
> >> Signed-off-by: Fang Jia <fang....@windriver.com>
> >> Reviewed-by: Jiwei Sun <jiwei....@windriver.com>
> >> Signed-off-by: De Huo <de....@windriver.com>
> >> ]
> >>
> >> Signed-off-by: Yanfei Xu <yanfei...@windriver.com>
> >> ---
> >> ...-backtrace-for-AAPCS-with-FP-enabled.patch | 93 +++++++++++++++++++
> >> patches/misc/misc.scc | 1 +
> >> 2 files changed, 94 insertions(+)
> >> create mode 100644
> >> patches/misc/arm64-perf-fix-backtrace-for-AAPCS-with-FP-enabled.patch
> >>
> >> diff --git
> >> a/patches/misc/arm64-perf-fix-backtrace-for-AAPCS-with-FP-enabled.patch
> >> b/patches/misc/arm64-perf-fix-backtrace-for-AAPCS-with-FP-enabled.patch
> >> new file mode 100644
> >> index 00000000..4c1e78cf
> >> --- /dev/null
> >> +++ b/patches/misc/arm64-perf-fix-backtrace-for-AAPCS-with-FP-enabled.patch
> >> @@ -0,0 +1,93 @@
> >> +From cbbce37ccc6041d3ae3d3cb3b1918a61a39820a0 Mon Sep 17 00:00:00 2001
> >> +From: Fang Jia <fang....@windriver.com>
> >> +Date: Fri, 28 Dec 2018 16:28:34 +0800
> >> +Subject: [PATCH] arm64/perf: fix backtrace for AAPCS with FP enabled
> >> +
> >> +This change is for arm64 platform compat mode.
> >> +The change for arm32 platform has been included in this commit "perf: fix
> >> +backtrace for AAPCS with FP enabled".
> >> +
> >> +This change replaces code designed for the obsolete ARM APCS ABI, which
> >> +causes failures of the perf backtrace logic unless the gcc option
> >> +-mapcs-frame is used to build all binaries on the platform. This
> >> +obsolete gcc option forces the compiler to include the stack pointer
> >> +along with the frame pointer and link register in the stack frame
> >> +for each funciton call. The current AAPCS ABI document, doesn't
> >> +explicitly describe the frame structure when the gcc frame pointer
> >> +option, -fno-omit-frame-pointer, is enabled. However, with this option
> >> +enabled, examination of the emitted prologue instructions shows that
> >> +1) R11 is used as the frame pointer,
> >> +2) only the R11 and LR are saved onto the stack, not the stack pointer,
> >> +3) after this prologue setup, the frame pointer, R11 points to the
> >> +saved location of LR on the stack.
> >> +
> >> +The use of unsigned int arithmetic in the commit is required since
> >> +the gcc emitted pointer arithmetic uses 8-byte pointer sizes, which are
> >> +incorrect addresses for the 4-byte stack address size.
> >> +
> >> +Signed-off-by: Fang Jia <fang....@windriver.com>
> >> +Reviewed-by: Jiwei Sun <jiwei....@windriver.com>
> >> +Signed-off-by: De Huo <de....@windriver.com>
> >> +---
> >> + arch/arm64/kernel/perf_callchain.c | 25 +++++++++++++++----------
> >> + 1 file changed, 15 insertions(+), 10 deletions(-)
> >> +
> >> +diff --git a/arch/arm64/kernel/perf_callchain.c
> >> b/arch/arm64/kernel/perf_callchain.c
> >> +index 9d63514b9836..b9bbe0b04fc1 100644
> >> +--- a/arch/arm64/kernel/perf_callchain.c
> >> ++++ b/arch/arm64/kernel/perf_callchain.c
> >> +@@ -54,16 +54,22 @@ user_backtrace(struct frame_tail __user *tail,
> >> +
> >> + #ifdef CONFIG_COMPAT
> >> + /*
> >> +- * The registers we're interested in are at the end of the variable
> >> +- * length saved register structure. The fp points at the end of this
> >> +- * structure so the address of this struct is:
> >> +- * (struct compat_frame_tail *)(xxx->fp)-1
> >> ++ * The AAPCS ABI, the most current replacing the obsolete APCS ABI,
> >> ++ * does not specifically describe the stack frame with respect to the
> >> ++ * frame pointer. However, the examination of emitted prologue
> >> ++ * instructions for ARM implies that with -fno-omit-framepointer,
> >> ++ * register R11 is used as the frame pointer register and saved on the
> >> ++ * stack, with LR.
> >> + *
> >> +- * This code has been adapted from the ARM OProfile support.
> >> ++ * After the prolog, the FP points to the location of the saved LR and
> >> ++ * FP+4 points to the previous frames FP as shown below:
> >> ++ * Stack Hi Mem
> >> ++ * (Value of FP)+4 Saved FP for caller
> >> ++ * (Value of FP) LR set by caller
> >> ++ * Stack Lo Mem
> >> + */
> >> + struct compat_frame_tail {
> >> + compat_uptr_t fp; /* a (struct compat_frame_tail *) in compat mode
> >> */
> >> +- u32 sp;
> >> + u32 lr;
> >> + } __attribute__((packed));
> >> +
> >> +@@ -91,11 +97,10 @@ compat_user_backtrace(struct compat_frame_tail __user
> >> *tail,
> >> + * Frame pointers should strictly progress back up the stack
> >> + * (towards higher addresses).
> >> + */
> >> +- if (tail + 1 >= (struct compat_frame_tail __user *)
> >> +- compat_ptr(buftail.fp))
> >> ++ if ((u32)tail + 4 >= buftail.fp)
> >> + return NULL;
> >> +
> >> +- return (struct compat_frame_tail __user *)compat_ptr(buftail.fp) - 1;
> >> ++ return (struct compat_frame_tail __user *)(buftail.fp - 4);
> >> + }
> >> + #endif /* CONFIG_COMPAT */
> >> +
> >> +@@ -123,7 +128,7 @@ void perf_callchain_user(struct
> >> perf_callchain_entry_ctx *entry,
> >> + /* AARCH32 compat mode */
> >> + struct compat_frame_tail __user *tail;
> >> +
> >> +- tail = (struct compat_frame_tail __user *)regs->compat_fp - 1;
> >> ++ tail = (struct compat_frame_tail __user *)(regs->compat_fp -
> >> 4);
> >> +
> >> + while ((entry->nr < entry->max_stack) &&
> >> + tail && !((unsigned long)tail & 0x3))
> >> +--
> >> +2.17.1
> >> +
> >> diff --git a/patches/misc/misc.scc b/patches/misc/misc.scc
> >> index dc091c36..910b4d36 100644
> >> --- a/patches/misc/misc.scc
> >> +++ b/patches/misc/misc.scc
> >> @@ -8,3 +8,4 @@ patch
> >> uvesafb-provide-option-to-specify-timeout-for-task-c.patch
> >> patch linux-yocto-Handle-bin-awk-issues.patch
> >> patch modpost-srcversion-sometimes-incorrect.patch
> >> patch x86-boot-compressed-64-Define-__force_order-only-whe.patch
> >> +patch arm64-perf-fix-backtrace-for-AAPCS-with-FP-enabled.patch
> >> --
> >> 2.18.2
> >>
--
- Thou shalt not follow the NULL pointer, for chaos and madness await
thee at its end
- "Use the force Harry" - Gandalf, Star Trek II
-=-=-=-=-=-=-=-=-=-=-=-
Links: You receive all messages sent to this group.
View/Reply Online (#8637):
https://lists.yoctoproject.org/g/linux-yocto/message/8637
Mute This Topic: https://lists.yoctoproject.org/mt/73303101/21656
Group Owner: linux-yocto+ow...@lists.yoctoproject.org
Unsubscribe:
https://lists.yoctoproject.org/g/linux-yocto/leave/6687884/624485779/xyzzy
[arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-
