| Message ID | 20220809105425.424045-1-naveen.n.rao@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 7af82ff90a2b0690c2c45818fcce4c4ac3b187f3 |
| Headers | show |
| Series | powerpc/ftrace: Ignore weak functions | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 10 jobs. |
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 10 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | success | Successfully ran 4 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 23 jobs. |
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 6 jobs. |
On Tue, 9 Aug 2022 16:24:25 +0530 "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> wrote: > Extend commit b39181f7c6907d ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to > avoid adding weak function") to ppc32 and ppc64 -mprofile-kernel by > defining FTRACE_MCOUNT_MAX_OFFSET. > > For ppc64 -mprofile-kernel ABI, we can have two instructions at function > entry for TOC setup followed by 'mflr r0' and 'bl _mcount'. So, the > mcount location is at most the 4th instruction in a function. For ppc32, > mcount location is always the 3rd instruction in a function, preceded by > 'mflr r0' and 'stw r0,4(r1)'. > > With this patch, and with ppc64le_guest_defconfig and some ftrace/bpf > config items enabled: > # grep __ftrace_invalid_address available_filter_functions | wc -l > 79 I wonder if this patch answers the question to my last email. ;-) Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> -- Steve > > Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> > --- > arch/powerpc/include/asm/ftrace.h | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h > index 3cee7115441b41..ade406dc6504e3 100644 > --- a/arch/powerpc/include/asm/ftrace.h > +++ b/arch/powerpc/include/asm/ftrace.h > @@ -10,6 +10,13 @@ > > #define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR > > +/* Ignore unused weak functions which will have larger offsets */ > +#ifdef CONFIG_MPROFILE_KERNEL > +#define FTRACE_MCOUNT_MAX_OFFSET 12 > +#elif defined(CONFIG_PPC32) > +#define FTRACE_MCOUNT_MAX_OFFSET 8 > +#endif > + > #ifndef __ASSEMBLY__ > extern void _mcount(void); > > > base-commit: ff1ed171e05c971652a0ede3d716997de8ee41c9
On Tue, 9 Aug 2022 16:24:25 +0530, Naveen N. Rao wrote: > Extend commit b39181f7c6907d ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to > avoid adding weak function") to ppc32 and ppc64 -mprofile-kernel by > defining FTRACE_MCOUNT_MAX_OFFSET. > > For ppc64 -mprofile-kernel ABI, we can have two instructions at function > entry for TOC setup followed by 'mflr r0' and 'bl _mcount'. So, the > mcount location is at most the 4th instruction in a function. For ppc32, > mcount location is always the 3rd instruction in a function, preceded by > 'mflr r0' and 'stw r0,4(r1)'. > > [...] Applied to powerpc/next. [1/1] powerpc/ftrace: Ignore weak functions https://git.kernel.org/powerpc/c/7af82ff90a2b0690c2c45818fcce4c4ac3b187f3 cheers
diff --git a/arch/powerpc/include/asm/ftrace.h b/arch/powerpc/include/asm/ftrace.h index 3cee7115441b41..ade406dc6504e3 100644 --- a/arch/powerpc/include/asm/ftrace.h +++ b/arch/powerpc/include/asm/ftrace.h @@ -10,6 +10,13 @@ #define HAVE_FUNCTION_GRAPH_RET_ADDR_PTR +/* Ignore unused weak functions which will have larger offsets */ +#ifdef CONFIG_MPROFILE_KERNEL +#define FTRACE_MCOUNT_MAX_OFFSET 12 +#elif defined(CONFIG_PPC32) +#define FTRACE_MCOUNT_MAX_OFFSET 8 +#endif + #ifndef __ASSEMBLY__ extern void _mcount(void);
Extend commit b39181f7c6907d ("ftrace: Add FTRACE_MCOUNT_MAX_OFFSET to avoid adding weak function") to ppc32 and ppc64 -mprofile-kernel by defining FTRACE_MCOUNT_MAX_OFFSET. For ppc64 -mprofile-kernel ABI, we can have two instructions at function entry for TOC setup followed by 'mflr r0' and 'bl _mcount'. So, the mcount location is at most the 4th instruction in a function. For ppc32, mcount location is always the 3rd instruction in a function, preceded by 'mflr r0' and 'stw r0,4(r1)'. With this patch, and with ppc64le_guest_defconfig and some ftrace/bpf config items enabled: # grep __ftrace_invalid_address available_filter_functions | wc -l 79 Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> --- arch/powerpc/include/asm/ftrace.h | 7 +++++++ 1 file changed, 7 insertions(+) base-commit: ff1ed171e05c971652a0ede3d716997de8ee41c9