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| author |   Ilya Leoshkevich <iii@linux.ibm.com> | 2020-06-30 20:52:03 +0200 |
|---|---|---|
| committer |   Heiko Carstens <hca@linux.ibm.com> | 2020-07-20 10:55:50 +0200 |
| commit | 05a68e892e89c97df6650cd8cc55058002657cbc (patch) | |
| tree | 50da3706b76870f99a1acf549c9cbf4227388baf /scripts/sorttable.c | |
| parent | s390/kernel: unify EX_TABLE* implementations (diff) | |
| download | linux-dev-05a68e892e89c97df6650cd8cc55058002657cbc.tar.xz linux-dev-05a68e892e89c97df6650cd8cc55058002657cbc.zip | |
s390/kernel: expand exception table logic to allow new handling options
This is a s390 port of commit 548acf19234d ("x86/mm: Expand the
exception table logic to allow new handling options"), which is needed
for implementing BPF_PROBE_MEM on s390.
The new handler field is made 64-bit in order to allow pointing from
dynamically allocated entries to handlers in kernel text. Unlike on x86,
NULL is used instead of ex_handler_default. This is because exception
tables are used by boot/text_dma.S, and it would be a pain to preserve
ex_handler_default.
The new infrastructure is ignored in early_pgm_check_handler, since
there is no pt_regs.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Diffstat (limited to 'scripts/sorttable.c')
| -rw-r--r-- | scripts/sorttable.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/scripts/sorttable.c b/scripts/sorttable.c index ec6b5e81eba1..0ef3abfc4a51 100644 --- a/scripts/sorttable.c +++ b/scripts/sorttable.c @@ -255,6 +255,45 @@ static void x86_sort_relative_table(char *extab_image, int image_size) } } +static void s390_sort_relative_table(char *extab_image, int image_size) +{ + int i; + + for (i = 0; i < image_size; i += 16) { + char *loc = extab_image + i; + uint64_t handler; + + w(r((uint32_t *)loc) + i, (uint32_t *)loc); + w(r((uint32_t *)(loc + 4)) + (i + 4), (uint32_t *)(loc + 4)); + /* + * 0 is a special self-relative handler value, which means that + * handler should be ignored. It is safe, because it means that + * handler field points to itself, which should never happen. + * When creating extable-relative values, keep it as 0, since + * this should never occur either: it would mean that handler + * field points to the first extable entry. + */ + handler = r8((uint64_t *)(loc + 8)); + if (handler) + handler += i + 8; + w8(handler, (uint64_t *)(loc + 8)); + } + + qsort(extab_image, image_size / 16, 16, compare_relative_table); + + for (i = 0; i < image_size; i += 16) { + char *loc = extab_image + i; + uint64_t handler; + + w(r((uint32_t *)loc) - i, (uint32_t *)loc); + w(r((uint32_t *)(loc + 4)) - (i + 4), (uint32_t *)(loc + 4)); + handler = r8((uint64_t *)(loc + 8)); + if (handler) + handler -= i + 8; + w8(handler, (uint64_t *)(loc + 8)); + } +} + static int do_file(char const *const fname, void *addr) { int rc = -1; @@ -297,6 +336,8 @@ static int do_file(char const *const fname, void *addr) custom_sort = x86_sort_relative_table; break; case EM_S390: + custom_sort = s390_sort_relative_table; + break; case EM_AARCH64: case EM_PARISC: case EM_PPC: |