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| author | Joerg Roedel <jroedel@suse.de> | 2020-09-07 15:15:43 +0200 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-09-09 11:33:19 +0200 |
| commit | 02772fb9b68e6a72a5e17f994048df832fe2b15e (patch) | |
| tree | ac6c3c2e41d924a7ddd9bbce6d605b0790dbc978 /arch/x86/kernel/dumpstack_64.c | |
| parent | 885689e47dfa1499b756a07237eb645234d93cf9 (diff) | |
| download | kernel_replicant_linux-02772fb9b68e6a72a5e17f994048df832fe2b15e.tar.gz kernel_replicant_linux-02772fb9b68e6a72a5e17f994048df832fe2b15e.tar.bz2 kernel_replicant_linux-02772fb9b68e6a72a5e17f994048df832fe2b15e.zip | |
x86/sev-es: Allocate and map an IST stack for #VC handler
Allocate and map an IST stack and an additional fall-back stack for
the #VC handler. The memory for the stacks is allocated only when
SEV-ES is active.
The #VC handler needs to use an IST stack because a #VC exception can be
raised from kernel space with unsafe stack, e.g. in the SYSCALL entry
path.
Since the #VC exception can be nested, the #VC handler switches back to
the interrupted stack when entered from kernel space. If switching back
is not possible, the fall-back stack is used.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200907131613.12703-43-joro@8bytes.org
Diffstat (limited to 'arch/x86/kernel/dumpstack_64.c')
| -rw-r--r-- | arch/x86/kernel/dumpstack_64.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c index 4a94d38cd141..c49cf594714b 100644 --- a/arch/x86/kernel/dumpstack_64.c +++ b/arch/x86/kernel/dumpstack_64.c @@ -24,11 +24,13 @@ static const char * const exception_stack_names[] = { [ ESTACK_NMI ] = "NMI", [ ESTACK_DB ] = "#DB", [ ESTACK_MCE ] = "#MC", + [ ESTACK_VC ] = "#VC", + [ ESTACK_VC2 ] = "#VC2", }; const char *stack_type_name(enum stack_type type) { - BUILD_BUG_ON(N_EXCEPTION_STACKS != 4); + BUILD_BUG_ON(N_EXCEPTION_STACKS != 6); if (type == STACK_TYPE_IRQ) return "IRQ"; @@ -79,6 +81,8 @@ struct estack_pages estack_pages[CEA_ESTACK_PAGES] ____cacheline_aligned = { EPAGERANGE(NMI), EPAGERANGE(DB), EPAGERANGE(MCE), + EPAGERANGE(VC), + EPAGERANGE(VC2), }; static bool in_exception_stack(unsigned long *stack, struct stack_info *info) @@ -88,7 +92,7 @@ static bool in_exception_stack(unsigned long *stack, struct stack_info *info) struct pt_regs *regs; unsigned int k; - BUILD_BUG_ON(N_EXCEPTION_STACKS != 4); + BUILD_BUG_ON(N_EXCEPTION_STACKS != 6); begin = (unsigned long)__this_cpu_read(cea_exception_stacks); /* |