| Message ID | 20190520231948.49693-3-thgarnie@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | x86: PIE support to extend KASLR randomization | expand |
On Mon, May 20, 2019 at 4:20 PM Thomas Garnier <thgarnie@chromium.org> wrote: > > From: Thomas Garnier <thgarnie@google.com> > > Replace the %c constraint with %P. The %c is incompatible with PIE > because it implies an immediate value whereas %P reference a symbol. > Change the _ASM_PTR reference to .long for expected relocation size and > add a long padding to ensure entry alignment. > > Position Independent Executable (PIE) support will allow to extend the > KASLR randomization range below 0xffffffff80000000. > > Signed-off-by: Thomas Garnier <thgarnie@google.com> > --- > arch/x86/include/asm/jump_label.h | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h > index 65191ce8e1cf..e47fad8ee632 100644 > --- a/arch/x86/include/asm/jump_label.h > +++ b/arch/x86/include/asm/jump_label.h > @@ -25,9 +25,9 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran > ".pushsection __jump_table, \"aw\" \n\t" > _ASM_ALIGN "\n\t" > ".long 1b - ., %l[l_yes] - . \n\t" > - _ASM_PTR "%c0 + %c1 - .\n\t" > + _ASM_PTR "%P0 - .\n\t" > ".popsection \n\t" > - : : "i" (key), "i" (branch) : : l_yes); > + : : "X" (&((char *)key)[branch]) : : l_yes); > > return false; > l_yes: > @@ -42,9 +42,9 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool > ".pushsection __jump_table, \"aw\" \n\t" > _ASM_ALIGN "\n\t" > ".long 1b - ., %l[l_yes] - . \n\t" > - _ASM_PTR "%c0 + %c1 - .\n\t" > + _ASM_PTR "%P0 - .\n\t" > ".popsection \n\t" > - : : "i" (key), "i" (branch) : : l_yes); > + : : "X" (&((char *)key)[branch]) : : l_yes); > > return false; > l_yes: > -- > 2.21.0.1020.gf2820cf01a-goog > Realized I forgot to address a feedback from the previous iteration on this specific patch. Ignore it I will work to check if it can be remove on the next iteration.
diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h index 65191ce8e1cf..e47fad8ee632 100644 --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -25,9 +25,9 @@ static __always_inline bool arch_static_branch(struct static_key *key, bool bran ".pushsection __jump_table, \"aw\" \n\t" _ASM_ALIGN "\n\t" ".long 1b - ., %l[l_yes] - . \n\t" - _ASM_PTR "%c0 + %c1 - .\n\t" + _ASM_PTR "%P0 - .\n\t" ".popsection \n\t" - : : "i" (key), "i" (branch) : : l_yes); + : : "X" (&((char *)key)[branch]) : : l_yes); return false; l_yes: @@ -42,9 +42,9 @@ static __always_inline bool arch_static_branch_jump(struct static_key *key, bool ".pushsection __jump_table, \"aw\" \n\t" _ASM_ALIGN "\n\t" ".long 1b - ., %l[l_yes] - . \n\t" - _ASM_PTR "%c0 + %c1 - .\n\t" + _ASM_PTR "%P0 - .\n\t" ".popsection \n\t" - : : "i" (key), "i" (branch) : : l_yes); + : : "X" (&((char *)key)[branch]) : : l_yes); return false; l_yes: