Messages in this thread | | | Date | Fri, 21 Apr 2017 13:32:10 +0000 | From | "Naveen N. Rao" <> | Subject | Re: [PATCH v2 3/3] powerpc/mm: Implement CONFIG_DEBUG_RODATA on PPC32 |
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Excerpts from Christophe Leroy's message of April 21, 2017 18:32: > This patch implements CONFIG_DEBUG_RODATA on PPC32. > > As for CONFIG_DEBUG_PAGEALLOC, it deactivates BAT and LTLB mappings > in order to allow page protection setup at the level of each page. > > As BAT/LTLB mappings are deactivated, their might be performance > impact. For this reason, we keep it OFF by default. > > Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[snip]
> diff --git a/arch/powerpc/kernel/ftrace.c > b/arch/powerpc/kernel/ftrace.c > index 32509de6ce4c..06d2ac53f471 100644 > --- a/arch/powerpc/kernel/ftrace.c > +++ b/arch/powerpc/kernel/ftrace.c > @@ -46,6 +46,7 @@ static int > ftrace_modify_code(unsigned long ip, unsigned int old, unsigned int new) > { > unsigned int replaced; > + int err; > > /* > * Note: > @@ -67,10 +68,11 @@ ftrace_modify_code(unsigned long ip, unsigned int old, unsigned int new) > } > > /* replace the text with the new text */ > - if (patch_instruction((unsigned int *)ip, new)) > - return -EPERM; > + set_kernel_text_rw(ip); > + err = patch_instruction((unsigned int *)ip, new); > + set_kernel_text_ro(ip);
Is there a reason to not put those inside patch_instruction()?
- Naveen
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