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| author | Catalin Marinas <catalin.marinas@arm.com> | 2021-12-14 19:11:52 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2021-12-14 19:11:52 +0100 |
| commit | 580b536b504fb13bea6e19e399e207e7253ca30a (patch) | |
| tree | 6f8f0d3bafd40c186bad31a9afb07f8789aa9c89 | |
| parent | Linux 5.16-rc3 (diff) | |
| parent | arm64: ftrace: add missing BTIs (diff) | |
| download | linux-580b536b504fb13bea6e19e399e207e7253ca30a.tar.xz linux-580b536b504fb13bea6e19e399e207e7253ca30a.zip | |
Merge 'arm64/for-next/fixes' into for-next/bti
Needed for the arch/arm64/kernel/entry-ftrace.S fix.
* commit 'arm64/for-next/fixes^^':
arm64: ftrace: add missing BTIs
arm64: kexec: use __pa_symbol(empty_zero_page)
arm64: update PAC description for kernel
| -rw-r--r-- | Documentation/arm64/pointer-authentication.rst | 9 | ||||
| -rw-r--r-- | arch/arm64/kernel/entry-ftrace.S | 6 | ||||
| -rw-r--r-- | arch/arm64/kernel/machine_kexec.c | 2 |
3 files changed, 11 insertions, 6 deletions
diff --git a/Documentation/arm64/pointer-authentication.rst b/Documentation/arm64/pointer-authentication.rst index f127666ea3a8..e5dad2e40aa8 100644 --- a/Documentation/arm64/pointer-authentication.rst +++ b/Documentation/arm64/pointer-authentication.rst @@ -53,11 +53,10 @@ The number of bits that the PAC occupies in a pointer is 55 minus the virtual address size configured by the kernel. For example, with a virtual address size of 48, the PAC is 7 bits wide. -Recent versions of GCC can compile code with APIAKey-based return -address protection when passed the -msign-return-address option. This -uses instructions in the HINT space (unless -march=armv8.3-a or higher -is also passed), and such code can run on systems without the pointer -authentication extension. +When ARM64_PTR_AUTH_KERNEL is selected, the kernel will be compiled +with HINT space pointer authentication instructions protecting +function returns. Kernels built with this option will work on hardware +with or without pointer authentication support. In addition to exec(), keys can also be reinitialized to random values using the PR_PAC_RESET_KEYS prctl. A bitmask of PR_PAC_APIAKEY, diff --git a/arch/arm64/kernel/entry-ftrace.S b/arch/arm64/kernel/entry-ftrace.S index b3e4f9a088b1..8cf970d219f5 100644 --- a/arch/arm64/kernel/entry-ftrace.S +++ b/arch/arm64/kernel/entry-ftrace.S @@ -77,11 +77,17 @@ .endm SYM_CODE_START(ftrace_regs_caller) +#ifdef BTI_C + BTI_C +#endif ftrace_regs_entry 1 b ftrace_common SYM_CODE_END(ftrace_regs_caller) SYM_CODE_START(ftrace_caller) +#ifdef BTI_C + BTI_C +#endif ftrace_regs_entry 0 b ftrace_common SYM_CODE_END(ftrace_caller) diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index 1038494135c8..6fb31c117ebe 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -147,7 +147,7 @@ int machine_kexec_post_load(struct kimage *kimage) if (rc) return rc; kimage->arch.ttbr1 = __pa(trans_pgd); - kimage->arch.zero_page = __pa(empty_zero_page); + kimage->arch.zero_page = __pa_symbol(empty_zero_page); reloc_size = __relocate_new_kernel_end - __relocate_new_kernel_start; memcpy(reloc_code, __relocate_new_kernel_start, reloc_size); |