[PATCH v4 05/27] x86: relocate_kernel - Adapt assembly for PIE support
Change the assembly code to use only relative references of symbols for the kernel to be PIE compatible. Position Independent Executable (PIE) support will allow to extend the KASLR randomization range 0x8000. Signed-off-by: Thomas Garnier --- arch/x86/kernel/relocate_kernel_64.S | 8 +--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index 11eda21eb697..a7227dfe1a2b 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -208,9 +208,11 @@ identity_mapped: movq%rax, %cr3 lea PAGE_SIZE(%r8), %rsp callswap_pages - movq$virtual_mapped, %rax - pushq %rax - ret + jmp *virtual_mapped_addr(%rip) + + /* Absolute value for PIE support */ +virtual_mapped_addr: + .quad virtual_mapped virtual_mapped: movqRSP(%r8), %rsp -- 2.17.0.921.gf22659ad46-goog
[PATCH v4 05/27] x86: relocate_kernel - Adapt assembly for PIE support
Change the assembly code to use only relative references of symbols for the kernel to be PIE compatible. Position Independent Executable (PIE) support will allow to extend the KASLR randomization range 0x8000. Signed-off-by: Thomas Garnier --- arch/x86/kernel/relocate_kernel_64.S | 8 +--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index 11eda21eb697..a7227dfe1a2b 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -208,9 +208,11 @@ identity_mapped: movq%rax, %cr3 lea PAGE_SIZE(%r8), %rsp callswap_pages - movq$virtual_mapped, %rax - pushq %rax - ret + jmp *virtual_mapped_addr(%rip) + + /* Absolute value for PIE support */ +virtual_mapped_addr: + .quad virtual_mapped virtual_mapped: movqRSP(%r8), %rsp -- 2.17.0.921.gf22659ad46-goog
