Commit f2a7e059 authored by James Morse's avatar James Morse Committed by Rafael J. Wysocki
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ACPI / APEI: Pass ghes and estatus separately to avoid a later copy 



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: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent b484079b

drivers/acpi/apei/ghes.c

+49 −43
Original line number Diff line number Diff line
@@ -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 @@ err_read_block: 
	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;



	if (ghes_estatus_cached(src_estatus))

		return;



	len = cper_estatus_len(ghes->estatus);

	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;

}

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