diff options
| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2017-11-21 17:28:20 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-11-22 15:04:20 +0300 |
| commit | 252eb55816a6f69ef9464cad303cdb3326cdc61d (patch) | |
| tree | 82da0aef8fcf25b6696049d5cae17d175ff9c800 /arch/powerpc/lib | |
| parent | f3f1dfd600ff82b18b7ea73d80eb27f476a6aa97 (diff) | |
| download | linux-252eb55816a6f69ef9464cad303cdb3326cdc61d.tar.xz | |
powerpc: Fix boot on BOOK3S_32 with CONFIG_STRICT_KERNEL_RWX
On powerpc32, patch_instruction() is called by apply_feature_fixups()
which is called from early_init()
There is the following note in front of early_init():
* Note that the kernel may be running at an address which is different
* from the address that it was linked at, so we must use RELOC/PTRRELOC
* to access static data (including strings). -- paulus
Therefore, slab_is_available() cannot be called yet, and
text_poke_area must be addressed with PTRRELOC()
Fixes: 95902e6c8864 ("powerpc/mm: Implement STRICT_KERNEL_RWX on PPC32")
Cc: stable@vger.kernel.org # v4.14+
Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/lib')
| -rw-r--r-- | arch/powerpc/lib/code-patching.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c index c9de03e0c1f1..d469224c4ada 100644 --- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c @@ -21,6 +21,7 @@ #include <asm/tlbflush.h> #include <asm/page.h> #include <asm/code-patching.h> +#include <asm/setup.h> static int __patch_instruction(unsigned int *addr, unsigned int instr) { @@ -146,11 +147,8 @@ int patch_instruction(unsigned int *addr, unsigned int instr) * During early early boot patch_instruction is called * when text_poke_area is not ready, but we still need * to allow patching. We just do the plain old patching - * We use slab_is_available and per cpu read * via this_cpu_read - * of text_poke_area. Per-CPU areas might not be up early - * this can create problems with just using this_cpu_read() */ - if (!slab_is_available() || !this_cpu_read(text_poke_area)) + if (!this_cpu_read(*PTRRELOC(&text_poke_area))) return __patch_instruction(addr, instr); local_irq_save(flags); |