Commit-ID: 883242dd0e5faaba041528a9a99f483f2a656c83 Gitweb: http://git.kernel.org/tip/883242dd0e5faaba041528a9a99f483f2a656c83 Author: Steven Rostedt <srostedt@xxxxxxxxxx> AuthorDate: Tue, 27 Oct 2009 13:15:11 -0400 Committer: Steven Rostedt <rostedt@xxxxxxxxxxx> CommitDate: Tue, 27 Oct 2009 13:15:11 -0400 tracing: allow to change permissions for text with dynamic ftrace enabled The commit 74e081797bd9d2a7d8005fe519e719df343a2ba8 x86-64: align RODATA kernel section to 2MB with CONFIG_DEBUG_RODATA prevents text sections from becoming read/write using set_memory_rw. The dynamic ftrace changes all text pages to read/write just before converting the calls to tracing to nops, and vice versa. I orginally just added a flag to allow this transaction when ftrace did the change, but I also found that when the CPA testing was running it would remove the read/write as well, and ftrace does not do the text conversion on boot up, and the CPA changes caused the dynamic tracer to fail on self tests. The current solution I have is to simply not to prevent change_page_attr from setting the RW bit for kernel text pages. Reported-by: Ingo Molnar <mingo@xxxxxxx> Cc: Suresh Siddha <suresh.b.siddha@xxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> --- arch/x86/mm/pageattr.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index b494fc4..78d3168 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -279,7 +279,8 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address, __pa((unsigned long)__end_rodata) >> PAGE_SHIFT)) pgprot_val(forbidden) |= _PAGE_RW; -#if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA) +#if defined(CONFIG_X86_64) && defined(CONFIG_DEBUG_RODATA) && \ + !defined(CONFIG_DYNAMIC_FTRACE) /* * Kernel text mappings for the large page aligned .rodata section * will be read-only. For the kernel identity mappings covering -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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