[PATCH v7 1/6] x86/sev: Fix calculation of end address based on number of pages

Tom Lendacky
2023-04-04T17:26:27Z

When calculating an end address based on an unsigned int number of pages,
any value greater than or equal to 0x100000 that is shift PAGE_SHIFT bits
results in a 0 value, resulting in an invalid end address. Change the
number of pages variable in various routines from an unsigned int to an
unsigned long to calculate the end address correctly.

Fixes: 5e5ccff60a29 ("x86/sev: Add helper for validating pages in early enc attribute changes")
Fixes: dc3f3d2474b8 ("x86/mm: Validate memory when changing the C-bit")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
arch/x86/include/asm/sev.h | 16 ++++++++--------
arch/x86/kernel/sev.c | 14 +++++++-------
2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h
index ebc271bb6d8e..a0a58c4122ec 100644
--- a/arch/x86/include/asm/sev.h
+++ b/arch/x86/include/asm/sev.h
@@ -187,12 +187,12 @@ static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate)
}
void setup_ghcb(void);
void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
- unsigned int npages);
+ unsigned long npages);
void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
- unsigned int npages);
+ unsigned long npages);
void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op);
-void snp_set_memory_shared(unsigned long vaddr, unsigned int npages);
-void snp_set_memory_private(unsigned long vaddr, unsigned int npages);
+void snp_set_memory_shared(unsigned long vaddr, unsigned long npages);
+void snp_set_memory_private(unsigned long vaddr, unsigned long npages);
void snp_set_wakeup_secondary_cpu(void);
bool snp_init(struct boot_params *bp);
void __init __noreturn snp_abort(void);
@@ -207,12 +207,12 @@ static inline int pvalidate(unsigned long vaddr, bool rmp_psize, bool validate)
static inline int rmpadjust(unsigned long vaddr, bool rmp_psize, unsigned long attrs) { return 0; }
static inline void setup_ghcb(void) { }
static inline void __init
-early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned int npages) { }
+early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, unsigned long npages) { }
static inline void __init
-early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, unsigned int npages) { }
+early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, unsigned long npages) { }
static inline void __init snp_prep_memory(unsigned long paddr, unsigned int sz, enum psc_op op) { }
-static inline void snp_set_memory_shared(unsigned long vaddr, unsigned int npages) { }
-static inline void snp_set_memory_private(unsigned long vaddr, unsigned int npages) { }
+static inline void snp_set_memory_shared(unsigned long vaddr, unsigned long npages) { }
+static inline void snp_set_memory_private(unsigned long vaddr, unsigned long npages) { }
static inline void snp_set_wakeup_secondary_cpu(void) { }
static inline bool snp_init(struct boot_params *bp) { return false; }
static inline void snp_abort(void) { }
diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
index 679026a640ef..72ef1e1fef84 100644
--- a/arch/x86/kernel/sev.c
+++ b/arch/x86/kernel/sev.c
@@ -643,7 +643,7 @@ static u64 __init get_jump_table_addr(void)
return ret;
}

-static void pvalidate_pages(unsigned long vaddr, unsigned int npages, bool validate)
+static void pvalidate_pages(unsigned long vaddr, unsigned long npages, bool validate)
{
unsigned long vaddr_end;
int rc;
@@ -660,7 +660,7 @@ static void pvalidate_pages(unsigned long vaddr, unsigned int npages, bool valid
}
}

-static void __init early_set_pages_state(unsigned long paddr, unsigned int npages, enum psc_op op)
+static void __init early_set_pages_state(unsigned long paddr, unsigned long npages, enum psc_op op)
{
unsigned long paddr_end;
u64 val;
@@ -699,7 +699,7 @@ static void __init early_set_pages_state(unsigned long paddr, unsigned int npage
}

void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr,
- unsigned int npages)
+ unsigned long npages)
{
/*
* This can be invoked in early boot while running identity mapped, so
@@ -721,7 +721,7 @@ void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long padd
}

void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr,
- unsigned int npages)
+ unsigned long npages)
{
/*
* This can be invoked in early boot while running identity mapped, so
@@ -877,7 +877,7 @@ static void __set_pages_state(struct snp_psc_desc *data, unsigned long vaddr,
sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC);
}

-static void set_pages_state(unsigned long vaddr, unsigned int npages, int op)
+static void set_pages_state(unsigned long vaddr, unsigned long npages, int op)
{
unsigned long vaddr_end, next_vaddr;
struct snp_psc_desc *desc;
@@ -902,7 +902,7 @@ static void set_pages_state(unsigned long vaddr, unsigned int npages, int op)
kfree(desc);
}

-void snp_set_memory_shared(unsigned long vaddr, unsigned int npages)
+void snp_set_memory_shared(unsigned long vaddr, unsigned long npages)
{
if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
return;
@@ -912,7 +912,7 @@ void snp_set_memory_shared(unsigned long vaddr, unsigned int npages)
set_pages_state(vaddr, npages, SNP_PAGE_STATE_SHARED);
}

-void snp_set_memory_private(unsigned long vaddr, unsigned int npages)
+void snp_set_memory_private(unsigned long vaddr, unsigned long npages)
{
if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP))
return;
--
2.40.0