diff options
Diffstat (limited to 'system/musl/dynamic-binary-stack-size.patch')
| -rw-r--r-- | system/musl/dynamic-binary-stack-size.patch | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/system/musl/dynamic-binary-stack-size.patch b/system/musl/dynamic-binary-stack-size.patch new file mode 100644 index 000000000..e2e3f12d3 --- /dev/null +++ b/system/musl/dynamic-binary-stack-size.patch @@ -0,0 +1,97 @@ +From 7b3348a98c139b4b4238384e52d4b0eb237e4833 Mon Sep 17 00:00:00 2001 +From: Rich Felker <dalias@aerifal.cx> +Date: Tue, 18 Sep 2018 23:54:18 -0400 +Subject: support setting of default thread stack size via PT_GNU_STACK header + +this facilitates building software that assumes a large default stack +size without any patching to call pthread_setattr_default_np or +pthread_attr_setstacksize at each thread creation site, using just +LDFLAGS. + +normally the PT_GNU_STACK header is used only to reflect whether +executable stack is desired, but with GNU ld at least, passing +-Wl,-z,stack-size=N will set a size on the program header. with this +patch, that size will be incorporated into the default stack size +(subject to increase-only rule and DEFAULT_STACK_MAX limit). + +both static and dynamic linking honor the program header. for dynamic +linking, all libraries loaded at program start, including preloaded +ones, are considered. dlopened libraries are not considered, for +several reasons. extra logic would be needed to defer processing until +the load of the new library is commited, synchronization woud be +needed since other threads may be running concurrently, and the +effectiveness woud be limited since the larger size would not apply to +threads that already existed at the time of dlopen. programs that will +dlopen code expecting a large stack need to declare the requirement +themselves, or pthread_setattr_default_np can be used. +--- + ldso/dynlink.c | 12 ++++++++++++ + src/env/__init_tls.c | 5 +++++ + 2 files changed, 17 insertions(+) + +diff --git a/ldso/dynlink.c b/ldso/dynlink.c +index e4829c3a..3ecbddfa 100644 +--- a/ldso/dynlink.c ++++ b/ldso/dynlink.c +@@ -22,6 +22,7 @@ + #include "dynlink.h" + + static void error(const char *, ...); ++extern size_t __default_stacksize; + + #define MAXP2(a,b) (-(-(a)&-(b))) + #define ALIGN(x,y) ((x)+(y)-1 & -(y)) +@@ -609,6 +610,12 @@ static void *map_library(int fd, struct dso *dso) + } else if (ph->p_type == PT_GNU_RELRO) { + dso->relro_start = ph->p_vaddr & -PAGE_SIZE; + dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE; ++ } else if (ph->p_type == PT_GNU_STACK) { ++ if (!runtime && ph->p_memsz > __default_stacksize) { ++ __default_stacksize = ++ ph->p_memsz < (8<<20) ? ++ ph->p_memsz : (8<<20); ++ } + } + if (ph->p_type != PT_LOAD) continue; + nsegs++; +@@ -1238,6 +1245,12 @@ static void kernel_mapped_dso(struct dso *p) + } else if (ph->p_type == PT_GNU_RELRO) { + p->relro_start = ph->p_vaddr & -PAGE_SIZE; + p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE; ++ } else if (ph->p_type == PT_GNU_STACK) { ++ if (!runtime && ph->p_memsz > __default_stacksize) { ++ __default_stacksize = ++ ph->p_memsz < (8<<20) ? ++ ph->p_memsz : (8<<20); ++ } + } + if (ph->p_type != PT_LOAD) continue; + if (ph->p_vaddr < min_addr) +diff --git a/src/env/__init_tls.c b/src/env/__init_tls.c +index e0224243..96d0e284 100644 +--- a/src/env/__init_tls.c ++++ b/src/env/__init_tls.c +@@ -8,6 +8,8 @@ + #include "atomic.h" + #include "syscall.h" + ++extern size_t __default_stacksize; ++ + int __init_tp(void *p) + { + pthread_t td = p; +@@ -90,6 +91,11 @@ static void static_init_tls(size_t *aux) + base = (size_t)_DYNAMIC - phdr->p_vaddr; + if (phdr->p_type == PT_TLS) + tls_phdr = phdr; ++ if (phdr->p_type == PT_GNU_STACK && ++ phdr->p_memsz > __default_stacksize) ++ __default_stacksize = ++ phdr->p_memsz < (8<<20) ? ++ phdr->p_memsz : (8<<20); + } + + if (tls_phdr) { +-- +cgit v1.2.1 + |