[PATCH v17 08/47] x86_64, dept: add support CONFIG_ARCH_HAS_DEPT_SUPPORT to x86_64
STALE306d
From: Byungchul Park <byungchul@sk.com>
Date: 2025-10-02 08:13:24
Also in:
dri-devel, linux-arch, linux-block, linux-doc, linux-ext4, linux-fsdevel, linux-i2c, linux-ide, linux-media, linux-mm, linux-modules, linux-nfs, linux-rt-devel, lkml, rcu
Subsystem:
the rest, x86 architecture (32-bit and 64-bit), x86 entry code, x86 mm · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski, Peter Zijlstra
Revision v17 of 12 in this series.
Revisions (12)
dept needs to notice every entrance from user to kernel mode to treat every kernel context independently when tracking wait-event dependencies. Roughly, system call and user oriented fault are the cases. Make dept aware of the entrances of x86_64 and add support CONFIG_ARCH_HAS_DEPT_SUPPORT to x86_64. Signed-off-by: Byungchul Park <byungchul@sk.com> --- arch/x86/Kconfig | 1 + arch/x86/entry/syscall_64.c | 7 +++++++ arch/x86/mm/fault.c | 7 +++++++ 3 files changed, 15 insertions(+)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 05880301212e..46021cf5934b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig@@ -38,6 +38,7 @@ config X86_64 select ZONE_DMA32 select EXECMEM if DYNAMIC_FTRACE select ACPI_MRRM if ACPI + select ARCH_HAS_DEPT_SUPPORT config FORCE_DYNAMIC_FTRACE def_bool y
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index b6e68ea98b83..66bd5af5aff1 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c@@ -8,6 +8,7 @@ #include <linux/entry-common.h> #include <linux/nospec.h> #include <asm/syscall.h> +#include <linux/dept.h> #define __SYSCALL(nr, sym) extern long __x64_##sym(const struct pt_regs *); #define __SYSCALL_NORETURN(nr, sym) extern long __noreturn __x64_##sym(const struct pt_regs *);
@@ -86,6 +87,12 @@ static __always_inline bool do_syscall_x32(struct pt_regs *regs, int nr) /* Returns true to return using SYSRET, or false to use IRET */ __visible noinstr bool do_syscall_64(struct pt_regs *regs, int nr) { + /* + * This is a system call from user mode. Make dept work with a + * new kernel mode context. + */ + dept_update_cxt(); + add_random_kstack_offset(); nr = syscall_enter_from_user_mode(regs, nr);
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 998bd807fc7b..017edb75f0a0 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c@@ -19,6 +19,7 @@ #include <linux/mm_types.h> #include <linux/mm.h> /* find_and_lock_vma() */ #include <linux/vmalloc.h> +#include <linux/dept.h> #include <asm/cpufeature.h> /* boot_cpu_has, ... */ #include <asm/traps.h> /* dotraplinkage, ... */
@@ -1219,6 +1220,12 @@ void do_user_addr_fault(struct pt_regs *regs, tsk = current; mm = tsk->mm; + /* + * This fault comes from user mode. Make dept work with a new + * kernel mode context. + */ + dept_update_cxt(); + if (unlikely((error_code & (X86_PF_USER | X86_PF_INSTR)) == X86_PF_INSTR)) { /* * Whoops, this is kernel mode code trying to execute from
--
2.17.1