linux-kernel - [PATCH 04/18] arm64: kernel: add helper for booted at EL2 and not VHE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210527150526.271941-5-pasha.tatashin@soleen.com>
Date:   Thu, 27 May 2021 11:05:12 -0400
From:   Pavel Tatashin <pasha.tatashin@...een.com>
To:     pasha.tatashin@...een.com, jmorris@...ei.org, sashal@...nel.org,
        ebiederm@...ssion.com, kexec@...ts.infradead.org,
        linux-kernel@...r.kernel.org, corbet@....net,
        catalin.marinas@....com, will@...nel.org,
        linux-arm-kernel@...ts.infradead.org, maz@...nel.org,
        james.morse@....com, vladimir.murzin@....com,
        matthias.bgg@...il.com, linux-mm@...ck.org, mark.rutland@....com,
        steve.capper@....com, rfontana@...hat.com, tglx@...utronix.de,
        selindag@...il.com, tyhicks@...ux.microsoft.com,
        kernelfans@...il.com, akpm@...ux-foundation.org,
        madvenka@...ux.microsoft.com
Subject: [PATCH 04/18] arm64: kernel: add helper for booted at EL2 and not VHE

Replace places that contain logic like this:
	is_hyp_mode_available() && !is_kernel_in_hyp_mode()

With a dedicated boolean function  is_hyp_callable(). This will be needed
later in kexec in order to sooner switch back to EL2.

Suggested-by: James Morse <james.morse@....com>

[Fixed merging issues]

Signed-off-by: Pavel Tatashin <pasha.tatashin@...een.com>
---
 arch/arm64/include/asm/virt.h | 5 +++++
 arch/arm64/kernel/cpu-reset.h | 3 +--
 arch/arm64/kernel/hibernate.c | 9 +++------
 arch/arm64/kernel/sdei.c      | 2 +-
 4 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
index 7379f35ae2c6..4216c8623538 100644
--- a/arch/arm64/include/asm/virt.h
+++ b/arch/arm64/include/asm/virt.h
@@ -128,6 +128,11 @@ static __always_inline bool is_protected_kvm_enabled(void)
 		return cpus_have_final_cap(ARM64_KVM_PROTECTED_MODE);
 }
 
+static inline bool is_hyp_callable(void)
+{
+	return is_hyp_mode_available() && !is_kernel_in_hyp_mode();
+}
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* ! __ASM__VIRT_H */
diff --git a/arch/arm64/kernel/cpu-reset.h b/arch/arm64/kernel/cpu-reset.h
index 9a7b1262ef17..48d0ed48c147 100644
--- a/arch/arm64/kernel/cpu-reset.h
+++ b/arch/arm64/kernel/cpu-reset.h
@@ -20,8 +20,7 @@ static inline void __noreturn __nocfi cpu_soft_restart(unsigned long entry,
 {
 	typeof(__cpu_soft_restart) *restart;
 
-	unsigned long el2_switch = !is_kernel_in_hyp_mode() &&
-		is_hyp_mode_available();
+	unsigned long el2_switch = is_hyp_callable();
 	restart = (void *)__pa_symbol(function_nocfi(__cpu_soft_restart));
 
 	cpu_install_idmap();
diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index b1cef371df2b..c764574a1acb 100644
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -48,9 +48,6 @@
  */
 extern int in_suspend;
 
-/* Do we need to reset el2? */
-#define el2_reset_needed() (is_hyp_mode_available() && !is_kernel_in_hyp_mode())
-
 /* temporary el2 vectors in the __hibernate_exit_text section. */
 extern char hibernate_el2_vectors[];
 
@@ -125,7 +122,7 @@ int arch_hibernation_header_save(void *addr, unsigned int max_size)
 	hdr->reenter_kernel	= _cpu_resume;
 
 	/* We can't use __hyp_get_vectors() because kvm may still be loaded */
-	if (el2_reset_needed())
+	if (is_hyp_callable())
 		hdr->__hyp_stub_vectors = __pa_symbol(__hyp_stub_vectors);
 	else
 		hdr->__hyp_stub_vectors = 0;
@@ -387,7 +384,7 @@ int swsusp_arch_suspend(void)
 		dcache_clean_range(__idmap_text_start, __idmap_text_end);
 
 		/* Clean kvm setup code to PoC? */
-		if (el2_reset_needed()) {
+		if (is_hyp_callable()) {
 			dcache_clean_range(__hyp_idmap_text_start, __hyp_idmap_text_end);
 			dcache_clean_range(__hyp_text_start, __hyp_text_end);
 		}
@@ -482,7 +479,7 @@ int swsusp_arch_resume(void)
 	 *
 	 * We can skip this step if we booted at EL1, or are running with VHE.
 	 */
-	if (el2_reset_needed()) {
+	if (is_hyp_callable()) {
 		phys_addr_t el2_vectors = (phys_addr_t)hibernate_exit;
 		el2_vectors += hibernate_el2_vectors -
 			       __hibernate_exit_text_start;     /* offset */
diff --git a/arch/arm64/kernel/sdei.c b/arch/arm64/kernel/sdei.c
index 2c7ca449dd51..af0ac2f920cf 100644
--- a/arch/arm64/kernel/sdei.c
+++ b/arch/arm64/kernel/sdei.c
@@ -200,7 +200,7 @@ unsigned long sdei_arch_get_entry_point(int conduit)
 	 * dropped to EL1 because we don't support VHE, then we can't support
 	 * SDEI.
 	 */
-	if (is_hyp_mode_available() && !is_kernel_in_hyp_mode()) {
+	if (is_hyp_callable()) {
 		pr_err("Not supported on this hardware/boot configuration\n");
 		goto out_err;
 	}
-- 
2.25.1