diff options
| author | Max Filippov <jcmvbkbc@gmail.com> | 2015-01-10 04:42:42 +0300 |
|---|---|---|
| committer | Bernhard Reutner-Fischer <rep.dot.nop@gmail.com> | 2015-01-23 21:16:12 +0100 |
| commit | 59f06d06f05abf20092617fcfa34438c77d92bdd (patch) | |
| tree | 6e189b6098366a78325bcf9f2b9bd38a09f585bf | |
| parent | e55f589191162eb40f44696c77e569049313d381 (diff) | |
xtensa: ldso: coalesce dl_mprotect address ranges
This noticeably lowers the number of mprotect calls at program startup,
e.g. for busybox: 7 calls vs 1835 calls.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>
| -rw-r--r-- | ldso/ldso/xtensa/dl-startup.h | 20 | ||||
| -rw-r--r-- | ldso/ldso/xtensa/dl-sysdep.h | 24 |
2 files changed, 42 insertions, 2 deletions
diff --git a/ldso/ldso/xtensa/dl-startup.h b/ldso/ldso/xtensa/dl-startup.h index b135a4cb8..0c28d5e44 100644 --- a/ldso/ldso/xtensa/dl-startup.h +++ b/ldso/ldso/xtensa/dl-startup.h @@ -83,6 +83,7 @@ do { \ unsigned long l_addr = tpnt->loadaddr; \ Elf32_Word relative_count; \ unsigned long rel_addr; \ + Elf32_Addr prev_got_start = 0, prev_got_end = 0; \ int x; \ \ got_loc = (xtensa_got_location *) \ @@ -93,7 +94,24 @@ do { \ got_start = got_loc[x].offset & ~(PAGE_SIZE - 1); \ got_end = ((got_loc[x].offset + got_loc[x].length + PAGE_SIZE - 1) \ & ~(PAGE_SIZE - 1)); \ - _dl_mprotect ((void *)(got_start + l_addr), got_end - got_start, \ + if (got_end >= prev_got_start && got_start <= prev_got_end) { \ + if (got_end > prev_got_end) \ + prev_got_end = got_end; \ + if (got_start < prev_got_start) \ + prev_got_start = got_start; \ + continue; \ + } else if (prev_got_start != prev_got_end) { \ + _dl_mprotect ((void *)(prev_got_start + l_addr), \ + prev_got_end - prev_got_start, \ + PROT_READ | PROT_WRITE | PROT_EXEC); \ + } \ + prev_got_start = got_start; \ + prev_got_end = got_end; \ + } \ +\ + if (prev_got_start != prev_got_end) { \ + _dl_mprotect ((void *)(prev_got_start + l_addr), \ + prev_got_end - prev_got_start, \ PROT_READ | PROT_WRITE | PROT_EXEC); \ } \ \ diff --git a/ldso/ldso/xtensa/dl-sysdep.h b/ldso/ldso/xtensa/dl-sysdep.h index a0ed4e5f2..5f8bcb0a8 100644 --- a/ldso/ldso/xtensa/dl-sysdep.h +++ b/ldso/ldso/xtensa/dl-sysdep.h @@ -36,6 +36,7 @@ typedef struct xtensa_got_location_struct { do { \ xtensa_got_location *got_loc; \ Elf32_Addr l_addr = MODULE->loadaddr; \ + Elf32_Addr prev_got_start = 0, prev_got_end = 0; \ int x; \ \ got_loc = (xtensa_got_location *) \ @@ -47,7 +48,28 @@ typedef struct xtensa_got_location_struct { got_start = got_loc[x].offset & ~(PAGE_SIZE - 1); \ got_end = ((got_loc[x].offset + got_loc[x].length + PAGE_SIZE - 1) \ & ~(PAGE_SIZE - 1)); \ - _dl_mprotect ((void *)(got_start + l_addr) , got_end - got_start, \ + if (got_end >= prev_got_start && got_start <= prev_got_end) \ + { \ + if (got_end > prev_got_end) \ + prev_got_end = got_end; \ + if (got_start < prev_got_start) \ + prev_got_start = got_start; \ + continue; \ + } \ + else if (prev_got_start != prev_got_end) \ + { \ + _dl_mprotect ((void *)(prev_got_start + l_addr), \ + prev_got_end - prev_got_start, \ + PROT_READ | PROT_WRITE | PROT_EXEC); \ + } \ + prev_got_start = got_start; \ + prev_got_end = got_end; \ + } \ + \ + if (prev_got_start != prev_got_end) \ + { \ + _dl_mprotect ((void *)(prev_got_start + l_addr), \ + prev_got_end - prev_got_start, \ PROT_READ | PROT_WRITE | PROT_EXEC); \ } \ \ |