[PATCH 6.4 085/239] x86/traps: Fix load_unaligned_zeropad() handling for shared TDX memory

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From: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>

[ Upstream commit 9f9116406120638b4d8db3831ffbc430dd2e1e95 ]

Commit c4e34dd99f2e ("x86: simplify load_unaligned_zeropad()
implementation") changes how exceptions around load_unaligned_zeropad()
handled.  The kernel now uses the fault_address in fixup_exception() to
verify the address calculations for the load_unaligned_zeropad().

It works fine for #PF, but breaks on #VE since no fault address is
passed down to fixup_exception().

Propagating ve_info.gla down to fixup_exception() resolves the issue.

See commit 1e7769653b06 ("x86/tdx: Handle load_unaligned_zeropad()
page-cross to a shared page") for more context.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Reported-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Fixes: c4e34dd99f2e ("x86: simplify load_unaligned_zeropad() implementation")
Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/x86/kernel/traps.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 58b1f208eff51..4a817d20ce3bb 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -697,9 +697,10 @@ static bool try_fixup_enqcmd_gp(void)
 }
 
 static bool gp_try_fixup_and_notify(struct pt_regs *regs, int trapnr,
-				    unsigned long error_code, const char *str)
+				    unsigned long error_code, const char *str,
+				    unsigned long address)
 {
-	if (fixup_exception(regs, trapnr, error_code, 0))
+	if (fixup_exception(regs, trapnr, error_code, address))
 		return true;
 
 	current->thread.error_code = error_code;
@@ -759,7 +760,7 @@ DEFINE_IDTENTRY_ERRORCODE(exc_general_protection)
 		goto exit;
 	}
 
-	if (gp_try_fixup_and_notify(regs, X86_TRAP_GP, error_code, desc))
+	if (gp_try_fixup_and_notify(regs, X86_TRAP_GP, error_code, desc, 0))
 		goto exit;
 
 	if (error_code)
@@ -1357,17 +1358,20 @@ DEFINE_IDTENTRY(exc_device_not_available)
 
 #define VE_FAULT_STR "VE fault"
 
-static void ve_raise_fault(struct pt_regs *regs, long error_code)
+static void ve_raise_fault(struct pt_regs *regs, long error_code,
+			   unsigned long address)
 {
 	if (user_mode(regs)) {
 		gp_user_force_sig_segv(regs, X86_TRAP_VE, error_code, VE_FAULT_STR);
 		return;
 	}
 
-	if (gp_try_fixup_and_notify(regs, X86_TRAP_VE, error_code, VE_FAULT_STR))
+	if (gp_try_fixup_and_notify(regs, X86_TRAP_VE, error_code,
+				    VE_FAULT_STR, address)) {
 		return;
+	}
 
-	die_addr(VE_FAULT_STR, regs, error_code, 0);
+	die_addr(VE_FAULT_STR, regs, error_code, address);
 }
 
 /*
@@ -1431,7 +1435,7 @@ DEFINE_IDTENTRY(exc_virtualization_exception)
 	 * it successfully, treat it as #GP(0) and handle it.
 	 */
 	if (!tdx_handle_virt_exception(regs, &ve))
-		ve_raise_fault(regs, 0);
+		ve_raise_fault(regs, 0, ve.gla);
 
 	cond_local_irq_disable(regs);
 }
-- 
2.39.2






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