From 40833b6701026a37243bda90bbd053c58963844d Mon Sep 17 00:00:00 2001 From: Juergen Gross To: x86@xxxxxxxxxx To: linux-kernel@xxxxxxxxxxxxxxx To: linux-pm@xxxxxxxxxxxxxxx Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Pavel Machek Cc: Juergen Gross Cc: Stefano Stabellini Cc: Oleksandr Tyshchenko Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx Date: Fri, 13 Jan 2023 08:37:45 +0100 Subject: [PATCH] x86/acpi: fix suspend with Xen MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit f1e525009493 ("x86/boot: Skip realmode init code when running as Xen PV guest") missed one code path accessing real_mode_header, leading to dereferencing NULL when suspending the system under Xen: [ 348.284004] PM: suspend entry (deep) [ 348.289532] Filesystems sync: 0.005 seconds [ 348.291545] Freezing user space processes ... (elapsed 0.000 seconds) done. [ 348.292457] OOM killer disabled. [ 348.292462] Freezing remaining freezable tasks ... (elapsed 0.104 seconds) done. [ 348.396612] printk: Suspending console(s) (use no_console_suspend to debug) [ 348.749228] PM: suspend devices took 0.352 seconds [ 348.769713] ACPI: EC: interrupt blocked [ 348.816077] BUG: kernel NULL pointer dereference, address: 000000000000001c [ 348.816080] #PF: supervisor read access in kernel mode [ 348.816081] #PF: error_code(0x0000) - not-present page [ 348.816083] PGD 0 P4D 0 [ 348.816086] Oops: 0000 [#1] PREEMPT SMP NOPTI [ 348.816089] CPU: 0 PID: 6764 Comm: systemd-sleep Not tainted 6.1.3-1.fc32.qubes.x86_64 #1 [ 348.816092] Hardware name: Star Labs StarBook/StarBook, BIOS 8.01 07/03/2022 [ 348.816093] RIP: e030:acpi_get_wakeup_address+0xc/0x20 Fix that by adding an indirection for acpi_get_wakeup_address() which Xen PV dom0 can use to return a dummy non-zero wakeup address (this address won't ever be used, as the real suspend handling is done by the hypervisor). Fixes: f1e525009493 ("x86/boot: Skip realmode init code when running as Xen PV guest") Reported-by: Marek Marczykowski-Górecki Signed-off-by: Juergen Gross --- arch/x86/include/asm/acpi.h | 2 +- arch/x86/kernel/acpi/sleep.c | 3 ++- include/xen/acpi.h | 9 +++++++++ 3 files changed, 12 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h index 65064d9f7fa6..137259ff8f03 100644 --- a/arch/x86/include/asm/acpi.h +++ b/arch/x86/include/asm/acpi.h @@ -61,7 +61,7 @@ static inline void acpi_disable_pci(void) extern int (*acpi_suspend_lowlevel)(void); /* Physical address to resume after wakeup */ -unsigned long acpi_get_wakeup_address(void); +extern unsigned long (*acpi_get_wakeup_address)(void); /* * Check if the CPU can handle C2 and deeper diff --git a/arch/x86/kernel/acpi/sleep.c b/arch/x86/kernel/acpi/sleep.c index 3b7f4cdbf2e0..1a3cd5e24cd0 100644 --- a/arch/x86/kernel/acpi/sleep.c +++ b/arch/x86/kernel/acpi/sleep.c @@ -33,10 +33,11 @@ static char temp_stack[4096]; * Returns the physical address where the kernel should be resumed after the * system awakes from S3, e.g. for programming into the firmware waking vector. */ -unsigned long acpi_get_wakeup_address(void) +static unsigned long x86_acpi_get_wakeup_address(void) { return ((unsigned long)(real_mode_header->wakeup_start)); } +unsigned long (*acpi_get_wakeup_address)(void) = x86_acpi_get_wakeup_address; /** * x86_acpi_enter_sleep_state - enter sleep state diff --git a/include/xen/acpi.h b/include/xen/acpi.h index b1e11863144d..7e1e5dbfb77c 100644 --- a/include/xen/acpi.h +++ b/include/xen/acpi.h @@ -56,6 +56,12 @@ static inline int xen_acpi_suspend_lowlevel(void) return 0; } +static inline unsigned long xen_acpi_get_wakeup_address(void) +{ + /* Just return a dummy non-zero value, it will never be used. */ + return 1; +} + static inline void xen_acpi_sleep_register(void) { if (xen_initial_domain()) { @@ -65,6 +71,9 @@ static inline void xen_acpi_sleep_register(void) &xen_acpi_notify_hypervisor_extended_sleep); acpi_suspend_lowlevel = xen_acpi_suspend_lowlevel; +#ifdef CONFIG_ACPI_SLEEP + acpi_get_wakeup_address = xen_acpi_get_wakeup_address; +#endif } } #else -- 2.35.3