diff options
| author | Helge Deller <deller@gmx.de> | 2016-04-08 18:32:52 +0200 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2016-05-01 00:05:23 +0200 |
| commit | 14313e39f3b33368020206940fe88fcf777b657e (patch) | |
| tree | 002e2b4ef79d141f9998bab2fff6ed25c92b5d03 /arch | |
| parent | 2e5c1b752c46b2bc61aa81f23b5a10f3a97bda76 (diff) | |
| download | linux-rt-14313e39f3b33368020206940fe88fcf777b657e.tar.gz | |
parisc: Unbreak handling exceptions from kernel modules
commit 2ef4dfd9d9f288943e249b78365a69e3ea3ec072 upstream.
Handling exceptions from modules never worked on parisc.
It was just masked by the fact that exceptions from modules
don't happen during normal use.
When a module triggers an exception in get_user() we need to load the
main kernel dp value before accessing the exception_data structure, and
afterwards restore the original dp value of the module on exit.
Noticed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Helge Deller <deller@gmx.de>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/parisc/include/asm/uaccess.h | 1 | ||||
| -rw-r--r-- | arch/parisc/kernel/asm-offsets.c | 1 | ||||
| -rw-r--r-- | arch/parisc/lib/fixup.S | 6 | ||||
| -rw-r--r-- | arch/parisc/mm/fault.c | 1 |
4 files changed, 9 insertions, 0 deletions
diff --git a/arch/parisc/include/asm/uaccess.h b/arch/parisc/include/asm/uaccess.h index ff4cf9dab8d2..337353de237b 100644 --- a/arch/parisc/include/asm/uaccess.h +++ b/arch/parisc/include/asm/uaccess.h @@ -79,6 +79,7 @@ struct exception_table_entry { */ struct exception_data { unsigned long fault_ip; + unsigned long fault_gp; unsigned long fault_space; unsigned long fault_addr; }; diff --git a/arch/parisc/kernel/asm-offsets.c b/arch/parisc/kernel/asm-offsets.c index dcd55103a4bb..a0dc1e50e3a3 100644 --- a/arch/parisc/kernel/asm-offsets.c +++ b/arch/parisc/kernel/asm-offsets.c @@ -292,6 +292,7 @@ int main(void) DEFINE(ASM_PT_INITIAL, PT_INITIAL); BLANK(); DEFINE(EXCDATA_IP, offsetof(struct exception_data, fault_ip)); + DEFINE(EXCDATA_GP, offsetof(struct exception_data, fault_gp)); DEFINE(EXCDATA_SPACE, offsetof(struct exception_data, fault_space)); DEFINE(EXCDATA_ADDR, offsetof(struct exception_data, fault_addr)); BLANK(); diff --git a/arch/parisc/lib/fixup.S b/arch/parisc/lib/fixup.S index f8c45cc2947d..138dd1e5a87a 100644 --- a/arch/parisc/lib/fixup.S +++ b/arch/parisc/lib/fixup.S @@ -26,6 +26,7 @@ #ifdef CONFIG_SMP .macro get_fault_ip t1 t2 + loadgp addil LT%__per_cpu_offset,%r27 LDREG RT%__per_cpu_offset(%r1),\t1 /* t2 = smp_processor_id() */ @@ -40,14 +41,19 @@ LDREG RT%exception_data(%r1),\t1 /* t1 = &__get_cpu_var(exception_data) */ add,l \t1,\t2,\t1 + /* %r27 = t1->fault_gp - restore gp */ + LDREG EXCDATA_GP(\t1), %r27 /* t1 = t1->fault_ip */ LDREG EXCDATA_IP(\t1), \t1 .endm #else .macro get_fault_ip t1 t2 + loadgp /* t1 = &__get_cpu_var(exception_data) */ addil LT%exception_data,%r27 LDREG RT%exception_data(%r1),\t2 + /* %r27 = t2->fault_gp - restore gp */ + LDREG EXCDATA_GP(\t2), %r27 /* t1 = t2->fault_ip */ LDREG EXCDATA_IP(\t2), \t1 .endm diff --git a/arch/parisc/mm/fault.c b/arch/parisc/mm/fault.c index a9b765a999ef..6471abb29cbb 100644 --- a/arch/parisc/mm/fault.c +++ b/arch/parisc/mm/fault.c @@ -147,6 +147,7 @@ int fixup_exception(struct pt_regs *regs) struct exception_data *d; d = &__get_cpu_var(exception_data); d->fault_ip = regs->iaoq[0]; + d->fault_gp = regs->gr[27]; d->fault_space = regs->isr; d->fault_addr = regs->ior; |