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From: James Morse <james.morse@arm.com>
To: linux-acpi@vger.kernel.org
Cc: Rafael Wysocki <rjw@rjwysocki.net>,
	Tony Luck <tony.luck@intel.com>, Xie XiuQi <xiexiuqi@huawei.com>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	Christoffer Dall <christoffer.dall@arm.com>,
	Dongjiu Geng <gengdongjiu@huawei.com>,
	linux-mm@kvack.org, Borislav Petkov <bp@alien8.de>,
	james.morse@arm.com, Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
	kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org, Len Brown <lenb@kernel.org>
Subject: [PATCH v8 17/26] ACPI / APEI: Pass ghes and estatus separately to avoid a later copy
Date: Tue, 29 Jan 2019 18:48:53 +0000
Message-ID: <20190129184902.102850-18-james.morse@arm.com> (raw)
In-Reply-To: <20190129184902.102850-1-james.morse@arm.com>

The NMI-like notifications scribble over ghes->estatus, before
copying it somewhere else. If this interrupts the ghes_probe() code
calling ghes_proc() on each struct ghes, the data is corrupted.

All the NMI-like notifications should use a queued estatus entry
from the beginning, instead of the ghes version, then copying it.
To do this, break up any use of "ghes->estatus" so that all
functions take the estatus as an argument.

This patch just moves these ghes->estatus dereferences into separate
arguments, no change in behaviour. struct ghes becomes unused in
ghes_clear_estatus() as it only wanted ghes->estatus, which we now
pass directly. This is removed.

Signed-off-by: James Morse <james.morse@arm.com>

---
Changes since v6:
 * Changed subject
 * Renamed ghes_estatus to src_estatus, which is a little clearer
 * Removed struct ghes from ghes_clear_estatus() now that this becomes
   unused in this patch.
 * Mangled the commit message to be different
---
 drivers/acpi/apei/ghes.c | 92 +++++++++++++++++++++-------------------
 1 file changed, 49 insertions(+), 43 deletions(-)

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index ccad57468ab7..f95db2398dd5 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -293,9 +293,9 @@ static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len,
 	}
 }
 
-static int ghes_read_estatus(struct ghes *ghes, u64 *buf_paddr,
-			     enum fixed_addresses fixmap_idx)
-
+static int ghes_read_estatus(struct ghes *ghes,
+			     struct acpi_hest_generic_status *estatus,
+			     u64 *buf_paddr, enum fixed_addresses fixmap_idx)
 {
 	struct acpi_hest_generic *g = ghes->generic;
 	u32 len;
@@ -312,25 +312,25 @@ static int ghes_read_estatus(struct ghes *ghes, u64 *buf_paddr,
 	if (!*buf_paddr)
 		return -ENOENT;
 
-	ghes_copy_tofrom_phys(ghes->estatus, *buf_paddr,
-			      sizeof(*ghes->estatus), 1, fixmap_idx);
-	if (!ghes->estatus->block_status) {
+	ghes_copy_tofrom_phys(estatus, *buf_paddr, sizeof(*estatus), 1,
+			      fixmap_idx);
+	if (!estatus->block_status) {
 		*buf_paddr = 0;
 		return -ENOENT;
 	}
 
 	rc = -EIO;
-	len = cper_estatus_len(ghes->estatus);
-	if (len < sizeof(*ghes->estatus))
+	len = cper_estatus_len(estatus);
+	if (len < sizeof(*estatus))
 		goto err_read_block;
 	if (len > ghes->generic->error_block_length)
 		goto err_read_block;
-	if (cper_estatus_check_header(ghes->estatus))
+	if (cper_estatus_check_header(estatus))
 		goto err_read_block;
-	ghes_copy_tofrom_phys(ghes->estatus + 1,
-			      *buf_paddr + sizeof(*ghes->estatus),
-			      len - sizeof(*ghes->estatus), 1, fixmap_idx);
-	if (cper_estatus_check(ghes->estatus))
+	ghes_copy_tofrom_phys(estatus + 1,
+			      *buf_paddr + sizeof(*estatus),
+			      len - sizeof(*estatus), 1, fixmap_idx);
+	if (cper_estatus_check(estatus))
 		goto err_read_block;
 	rc = 0;
 
@@ -342,16 +342,17 @@ static int ghes_read_estatus(struct ghes *ghes, u64 *buf_paddr,
 	return rc;
 }
 
-static void ghes_clear_estatus(struct ghes *ghes, u64 buf_paddr,
-			       enum fixed_addresses fixmap_idx)
+static void ghes_clear_estatus(struct ghes *ghes,
+			       struct acpi_hest_generic_status *estatus,
+			       u64 buf_paddr, enum fixed_addresses fixmap_idx)
 {
-	ghes->estatus->block_status = 0;
+	estatus->block_status = 0;
 
 	if (!buf_paddr)
 		return;
 
-	ghes_copy_tofrom_phys(ghes->estatus, buf_paddr,
-			      sizeof(ghes->estatus->block_status), 0,
+	ghes_copy_tofrom_phys(estatus, buf_paddr,
+			      sizeof(estatus->block_status), 0,
 			      fixmap_idx);
 
 	/*
@@ -651,12 +652,13 @@ static void ghes_estatus_cache_add(
 	rcu_read_unlock();
 }
 
-static void __ghes_panic(struct ghes *ghes, u64 buf_paddr,
-			 enum fixed_addresses fixmap_idx)
+static void __ghes_panic(struct ghes *ghes,
+			 struct acpi_hest_generic_status *estatus,
+			 u64 buf_paddr, enum fixed_addresses fixmap_idx)
 {
-	__ghes_print_estatus(KERN_EMERG, ghes->generic, ghes->estatus);
+	__ghes_print_estatus(KERN_EMERG, ghes->generic, estatus);
 
-	ghes_clear_estatus(ghes, buf_paddr, fixmap_idx);
+	ghes_clear_estatus(ghes, estatus, buf_paddr, fixmap_idx);
 
 	/* reboot to log the error! */
 	if (!panic_timeout)
@@ -666,25 +668,25 @@ static void __ghes_panic(struct ghes *ghes, u64 buf_paddr,
 
 static int ghes_proc(struct ghes *ghes)
 {
+	struct acpi_hest_generic_status *estatus = ghes->estatus;
 	u64 buf_paddr;
 	int rc;
 
-	rc = ghes_read_estatus(ghes, &buf_paddr, FIX_APEI_GHES_IRQ);
+	rc = ghes_read_estatus(ghes, estatus, &buf_paddr, FIX_APEI_GHES_IRQ);
 	if (rc)
 		goto out;
 
-	if (ghes_severity(ghes->estatus->error_severity) >= GHES_SEV_PANIC) {
-		__ghes_panic(ghes, buf_paddr, FIX_APEI_GHES_IRQ);
-	}
+	if (ghes_severity(estatus->error_severity) >= GHES_SEV_PANIC)
+		__ghes_panic(ghes, estatus, buf_paddr, FIX_APEI_GHES_IRQ);
 
-	if (!ghes_estatus_cached(ghes->estatus)) {
-		if (ghes_print_estatus(NULL, ghes->generic, ghes->estatus))
-			ghes_estatus_cache_add(ghes->generic, ghes->estatus);
+	if (!ghes_estatus_cached(estatus)) {
+		if (ghes_print_estatus(NULL, ghes->generic, estatus))
+			ghes_estatus_cache_add(ghes->generic, estatus);
 	}
-	ghes_do_proc(ghes, ghes->estatus);
+	ghes_do_proc(ghes, estatus);
 
 out:
-	ghes_clear_estatus(ghes, buf_paddr, FIX_APEI_GHES_IRQ);
+	ghes_clear_estatus(ghes, estatus, buf_paddr, FIX_APEI_GHES_IRQ);
 
 	return rc;
 }
@@ -825,17 +827,20 @@ static void ghes_print_queued_estatus(void)
 }
 
 /* Save estatus for further processing in IRQ context */
-static void __process_error(struct ghes *ghes)
+static void __process_error(struct ghes *ghes,
+			    struct acpi_hest_generic_status *src_estatus)
 {
-#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
 	u32 len, node_len;
 	struct ghes_estatus_node *estatus_node;
 	struct acpi_hest_generic_status *estatus;
 
-	if (ghes_estatus_cached(ghes->estatus))
+	if (!IS_ENABLED(CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG))
 		return;
 
-	len = cper_estatus_len(ghes->estatus);
+	if (ghes_estatus_cached(src_estatus))
+		return;
+
+	len = cper_estatus_len(src_estatus);
 	node_len = GHES_ESTATUS_NODE_LEN(len);
 
 	estatus_node = (void *)gen_pool_alloc(ghes_estatus_pool, node_len);
@@ -845,30 +850,31 @@ static void __process_error(struct ghes *ghes)
 	estatus_node->ghes = ghes;
 	estatus_node->generic = ghes->generic;
 	estatus = GHES_ESTATUS_FROM_NODE(estatus_node);
-	memcpy(estatus, ghes->estatus, len);
+	memcpy(estatus, src_estatus, len);
 	llist_add(&estatus_node->llnode, &ghes_estatus_llist);
-#endif
 }
 
 static int ghes_in_nmi_queue_one_entry(struct ghes *ghes,
 				       enum fixed_addresses fixmap_idx)
 {
+	struct acpi_hest_generic_status *estatus = ghes->estatus;
 	u64 buf_paddr;
 	int sev;
 
-	if (ghes_read_estatus(ghes, &buf_paddr, fixmap_idx)) {
-		ghes_clear_estatus(ghes, buf_paddr, fixmap_idx);
+	if (ghes_read_estatus(ghes, estatus, &buf_paddr, fixmap_idx)) {
+		ghes_clear_estatus(ghes, estatus, buf_paddr, fixmap_idx);
 		return -ENOENT;
 	}
 
-	sev = ghes_severity(ghes->estatus->error_severity);
+	sev = ghes_severity(estatus->error_severity);
 	if (sev >= GHES_SEV_PANIC) {
 		ghes_print_queued_estatus();
-		__ghes_panic(ghes, buf_paddr, fixmap_idx);
+		__ghes_panic(ghes, estatus, buf_paddr, fixmap_idx);
+
 	}
 
-	__process_error(ghes);
-	ghes_clear_estatus(ghes, buf_paddr, fixmap_idx);
+	__process_error(ghes, estatus);
+	ghes_clear_estatus(ghes, estatus, buf_paddr, fixmap_idx);
 
 	return 0;
 }
-- 
2.20.1


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  parent reply index

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-29 18:48 [PATCH v8 00/26] APEI in_nmi() rework and SDEI wire-up James Morse
2019-01-29 18:48 ` [PATCH v8 01/26] ACPI / APEI: Don't wait to serialise with oops messages when panic()ing James Morse
2019-01-29 18:48 ` [PATCH v8 02/26] ACPI / APEI: Remove silent flag from ghes_read_estatus() James Morse
2019-01-29 18:48 ` [PATCH v8 03/26] ACPI / APEI: Switch estatus pool to use vmalloc memory James Morse
2019-01-29 18:48 ` [PATCH v8 04/26] ACPI / APEI: Make hest.c manage the estatus memory pool James Morse
2019-02-01 13:20   ` Borislav Petkov
2019-01-29 18:48 ` [PATCH v8 05/26] ACPI / APEI: Make estatus pool allocation a static size James Morse
2019-01-29 18:48 ` [PATCH v8 06/26] ACPI / APEI: Don't store CPER records physical address in struct ghes James Morse
2019-01-29 18:48 ` [PATCH v8 07/26] ACPI / APEI: Remove spurious GHES_TO_CLEAR check James Morse
2019-01-29 18:48 ` [PATCH v8 08/26] ACPI / APEI: Don't update struct ghes' flags in read/clear estatus James Morse
2019-01-29 18:48 ` [PATCH v8 09/26] ACPI / APEI: Generalise the estatus queue's notify code James Morse
2019-02-01 13:46   ` Borislav Petkov
2019-01-29 18:48 ` [PATCH v8 10/26] ACPI / APEI: Don't allow ghes_ack_error() to mask earlier errors James Morse
2019-01-29 18:48 ` [PATCH v8 11/26] ACPI / APEI: Move NOTIFY_SEA between the estatus-queue and NOTIFY_NMI James Morse
2019-01-29 18:48 ` [PATCH v8 12/26] ACPI / APEI: Switch NOTIFY_SEA to use the estatus queue James Morse
2019-01-29 18:48 ` [PATCH v8 13/26] KVM: arm/arm64: Add kvm_ras.h to collect kvm specific RAS plumbing James Morse
2019-01-29 18:48 ` [PATCH v8 14/26] arm64: KVM/mm: Move SEA handling behind a single 'claim' interface James Morse
2019-01-29 18:48 ` [PATCH v8 15/26] ACPI / APEI: Move locking to the notification helper James Morse
2019-01-29 18:48 ` [PATCH v8 16/26] ACPI / APEI: Let the notification helper specify the fixmap slot James Morse
2019-01-29 18:48 ` James Morse [this message]
2019-01-29 18:48 ` [PATCH v8 18/26] ACPI / APEI: Make GHES estatus header validation more user friendly James Morse
2019-02-01 14:30   ` Borislav Petkov
2019-01-29 18:48 ` [PATCH v8 19/26] ACPI / APEI: Split ghes_read_estatus() to allow a peek at the CPER length James Morse
2019-01-29 18:48 ` [PATCH v8 20/26] ACPI / APEI: Only use queued estatus entry during in_nmi_queue_one_entry() James Morse
2019-01-29 18:48 ` [PATCH v8 21/26] ACPI / APEI: Use separate fixmap pages for arm64 NMI-like notifications James Morse
2019-01-29 18:48 ` [PATCH v8 22/26] mm/memory-failure: Add memory_failure_queue_kick() James Morse
2019-01-29 18:48 ` [PATCH v8 23/26] ACPI / APEI: Kick the memory_failure() queue for synchronous errors James Morse
2019-01-29 18:49 ` [PATCH v8 24/26] arm64: acpi: Make apei_claim_sea() synchronise with APEI's irq work James Morse
2019-01-30  8:56   ` Julien Thierry
2019-01-29 18:49 ` [PATCH v8 25/26] firmware: arm_sdei: Add ACPI GHES registration helper James Morse
2019-01-29 18:49 ` [PATCH v8 26/26] ACPI / APEI: Add support for the SDEI GHES Notification type James Morse
2019-02-08 11:40 ` [PATCH v8 00/26] APEI in_nmi() rework and SDEI wire-up Rafael J. Wysocki
2019-02-08 14:13   ` James Morse
2019-02-11 11:05     ` Rafael J. Wysocki
2019-02-11 18:35       ` James Morse
2019-02-12 22:14         ` Rafael J. Wysocki

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