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LibC: Save callee saved registers on setjmp

This commit is contained in:
Bananymous 2025-05-04 13:54:35 +03:00
parent d457e6ad6a
commit 82f4975f45
4 changed files with 43 additions and 11 deletions
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11
userspace/libraries/LibC/arch/i686/setjmp.S
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@ -1,3 +1,5 @@
// jmp_buf: esp, eip, ebx, ebp, edi, esi
// int setjmp(jmp_buf env) // int setjmp(jmp_buf env)
.global setjmp .global setjmp
setjmp: setjmp:
@ -9,6 +11,11 @@ setjmp:
movl (%esp), %eax movl (%esp), %eax
movl %eax, 4(%edx) movl %eax, 4(%edx)
movl %ebx, 8(%edx)
movl %ebp, 12(%edx)
movl %edi, 16(%edx)
movl %esi, 20(%edx)
xorl %eax, %eax xorl %eax, %eax
ret ret
@ -27,6 +34,10 @@ longjmp:
movl 0(%edx), %esp movl 0(%edx), %esp
movl 4(%edx), %ecx movl 4(%edx), %ecx
movl 8(%edx), %ebx
movl 12(%edx), %ebp
movl 16(%edx), %edi
movl 20(%edx), %esi
jmp *%ecx jmp *%ecx
.size longjmp, . - longjmp .size longjmp, . - longjmp

15
userspace/libraries/LibC/arch/x86_64/setjmp.S
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@ -1,3 +1,5 @@
// jmp_buf: rsp, rip, rbx, rbp, r12-r15
// int setjmp(jmp_buf env) // int setjmp(jmp_buf env)
.global setjmp .global setjmp
setjmp: setjmp:
@ -7,6 +9,13 @@ setjmp:
movq (%rsp), %rax movq (%rsp), %rax
movq %rax, 8(%rdi) movq %rax, 8(%rdi)
movq %rbx, 16(%rdi)
movq %rbp, 24(%rdi)
movq %r12, 32(%rdi)
movq %r13, 40(%rdi)
movq %r14, 48(%rdi)
movq %r15, 56(%rdi)
xorq %rax, %rax xorq %rax, %rax
ret ret
@ -21,5 +30,11 @@ longjmp:
movq 0(%rdi), %rsp movq 0(%rdi), %rsp
movq 8(%rdi), %rcx movq 8(%rdi), %rcx
movq 16(%rdi), %rbx
movq 24(%rdi), %rbp
movq 32(%rdi), %r12
movq 40(%rdi), %r13
movq 48(%rdi), %r14
movq 56(%rdi), %r15
jmp *%rcx jmp *%rcx
.size longjmp, . - longjmp .size longjmp, . - longjmp

10
userspace/libraries/LibC/include/setjmp.h
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@ -7,8 +7,14 @@
__BEGIN_DECLS __BEGIN_DECLS
typedef long jmp_buf[2]; #if defined(__x86_64__)
typedef long sigjmp_buf[2 + 1 + (sizeof(long long) / sizeof(long))]; #define _JMP_BUF_REGS 8 // rsp, rip, rbx, rbp, r12-r15
#elif defined(__i686__)
#define _JMP_BUF_REGS 6 // esp, eip, ebx, ebp, edi, esi
#endif
typedef long jmp_buf[_JMP_BUF_REGS];
typedef long sigjmp_buf[_JMP_BUF_REGS + 1 + (sizeof(long long) / sizeof(long))];
#define _longjmp longjmp #define _longjmp longjmp
void longjmp(jmp_buf env, int val); void longjmp(jmp_buf env, int val);

10
userspace/libraries/LibC/setjmp.cpp
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@ -1,19 +1,19 @@
#include <setjmp.h> #include <setjmp.h>
#include <signal.h> #include <signal.h>
static_assert(sizeof(sigjmp_buf) == sizeof(jmp_buf) + sizeof(long) + sizeof(sigset_t)); static_assert(sizeof(sigjmp_buf) == (_JMP_BUF_REGS + 1) * sizeof(long) + sizeof(sigset_t));
void siglongjmp(sigjmp_buf env, int val) void siglongjmp(sigjmp_buf env, int val)
{ {
if (env[2]) if (env[_JMP_BUF_REGS])
pthread_sigmask(SIG_SETMASK, reinterpret_cast<sigset_t*>(&env[3]), nullptr); pthread_sigmask(SIG_SETMASK, reinterpret_cast<sigset_t*>(&env[_JMP_BUF_REGS + 1]), nullptr);
return longjmp(env, val); return longjmp(env, val);
} }
int sigsetjmp(sigjmp_buf env, int savemask) int sigsetjmp(sigjmp_buf env, int savemask)
{ {
env[2] = savemask; env[_JMP_BUF_REGS] = savemask;
if (savemask) if (savemask)
pthread_sigmask(0, nullptr, reinterpret_cast<sigset_t*>(&env[3])); pthread_sigmask(0, nullptr, reinterpret_cast<sigset_t*>(&env[_JMP_BUF_REGS + 1]));
return setjmp(env); return setjmp(env);
} }