mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-08-05 16:54:27 +00:00
1623963097
Impact: keep kernel text read only Because dynamic ftrace converts the calls to mcount into and out of nops at run time, we needed to always keep the kernel text writable. But this defeats the point of CONFIG_DEBUG_RODATA. This patch converts the kernel code to writable before ftrace modifies the text, and converts it back to read only afterward. The kernel text is converted to read/write, stop_machine is called to modify the code, then the kernel text is converted back to read only. The original version used SYSTEM_STATE to determine when it was OK or not to change the code to rw or ro. Andrew Morton pointed out that using SYSTEM_STATE is a bad idea since there is no guarantee to what its state will actually be. Instead, I moved the check into the set_kernel_text_* functions themselves, and use a local variable to determine when it is OK to change the kernel text RW permissions. [ Update: Ingo Molnar suggested moving the prototypes to cacheflush.h ] Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Steven Rostedt <srostedt@redhat.com> |
||
|---|---|---|
| .. | ||
| dump_pagetables.c | ||
| extable.c | ||
| fault.c | ||
| gup.c | ||
| highmem_32.c | ||
| hugetlbpage.c | ||
| init_32.c | ||
| init_64.c | ||
| iomap_32.c | ||
| ioremap.c | ||
| k8topology_64.c | ||
| kmmio.c | ||
| Makefile | ||
| memtest.c | ||
| mmap.c | ||
| mmio-mod.c | ||
| numa_32.c | ||
| numa_64.c | ||
| pageattr-test.c | ||
| pageattr.c | ||
| pat.c | ||
| pf_in.c | ||
| pf_in.h | ||
| pgtable.c | ||
| pgtable_32.c | ||
| srat_32.c | ||
| srat_64.c | ||
| testmmiotrace.c | ||