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BACKPORT: ACPI / APEI: Pass ghes and estatus separately to avoid a la…
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…ter 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.

This patch is needed because Quicksilver firmware-first error handling
uses the SDEI notification type for communication between trusted
firmware and the OS. This adds needed NMI and SDEI functionality so
that the SDEI path in the kernel through APEI acts as an NMI and is
properly wired up to the APEI interfaces.

Backported from: torvalds/linux@f2a7e05

Signed-off-by: James Morse <[email protected]>
Signed-off-by: Tyler Baicar <[email protected]>
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@tphan-ampere
James Morse authored and tphan-ampere committed Apr 21, 2020
1 parent 71b03af commit 15304bd
Showing 1 changed file with 49 additions and 43 deletions.
92 changes: 49 additions & 43 deletions drivers/acpi/apei/ghes.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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;

Expand All @@ -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);

/*
Expand Down Expand Up @@ -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)
Expand All @@ -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;
}
Expand Down Expand Up @@ -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);
Expand All @@ -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;
}
Expand Down

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