diff options
Diffstat (limited to 'linux-user/host/arm/safe-syscall.inc.S')
| -rw-r--r-- | linux-user/host/arm/safe-syscall.inc.S | 134 |
1 files changed, 67 insertions, 67 deletions
diff --git a/linux-user/host/arm/safe-syscall.inc.S b/linux-user/host/arm/safe-syscall.inc.S index 88c4958504..1f1ee8327b 100644 --- a/linux-user/host/arm/safe-syscall.inc.S +++ b/linux-user/host/arm/safe-syscall.inc.S @@ -10,81 +10,81 @@ * See the COPYING file in the top-level directory. */ - .global safe_syscall_base - .global safe_syscall_start - .global safe_syscall_end - .type safe_syscall_base, %function + .global safe_syscall_base + .global safe_syscall_start + .global safe_syscall_end + .type safe_syscall_base, %function - .cfi_sections .debug_frame + .cfi_sections .debug_frame - .text - .syntax unified - .arm - .align 2 + .text + .syntax unified + .arm + .align 2 - /* This is the entry point for making a system call. The calling - * convention here is that of a C varargs function with the - * first argument an 'int *' to the signal_pending flag, the - * second one the system call number (as a 'long'), and all further - * arguments being syscall arguments (also 'long'). - * We return a long which is the syscall's return value, which - * may be negative-errno on failure. Conversion to the - * -1-and-errno-set convention is done by the calling wrapper. - */ + /* This is the entry point for making a system call. The calling + * convention here is that of a C varargs function with the + * first argument an 'int *' to the signal_pending flag, the + * second one the system call number (as a 'long'), and all further + * arguments being syscall arguments (also 'long'). + * We return a long which is the syscall's return value, which + * may be negative-errno on failure. Conversion to the + * -1-and-errno-set convention is done by the calling wrapper. + */ safe_syscall_base: - .fnstart - .cfi_startproc - mov r12, sp /* save entry stack */ - push { r4, r5, r6, r7, r8, lr } - .save { r4, r5, r6, r7, r8, lr } - .cfi_adjust_cfa_offset 24 - .cfi_rel_offset r4, 0 - .cfi_rel_offset r5, 4 - .cfi_rel_offset r6, 8 - .cfi_rel_offset r7, 12 - .cfi_rel_offset r8, 16 - .cfi_rel_offset lr, 20 + .fnstart + .cfi_startproc + mov r12, sp /* save entry stack */ + push { r4, r5, r6, r7, r8, lr } + .save { r4, r5, r6, r7, r8, lr } + .cfi_adjust_cfa_offset 24 + .cfi_rel_offset r4, 0 + .cfi_rel_offset r5, 4 + .cfi_rel_offset r6, 8 + .cfi_rel_offset r7, 12 + .cfi_rel_offset r8, 16 + .cfi_rel_offset lr, 20 - /* The syscall calling convention isn't the same as the C one: - * we enter with r0 == *signal_pending - * r1 == syscall number - * r2, r3, [sp+0] ... [sp+12] == syscall arguments - * and return the result in r0 - * and the syscall instruction needs - * r7 == syscall number - * r0 ... r6 == syscall arguments - * and returns the result in r0 - * Shuffle everything around appropriately. - * Note the 16 bytes that we pushed to save registers. - */ - mov r8, r0 /* copy signal_pending */ - mov r7, r1 /* syscall number */ - mov r0, r2 /* syscall args */ - mov r1, r3 - ldm r12, { r2, r3, r4, r5, r6 } + /* The syscall calling convention isn't the same as the C one: + * we enter with r0 == *signal_pending + * r1 == syscall number + * r2, r3, [sp+0] ... [sp+12] == syscall arguments + * and return the result in r0 + * and the syscall instruction needs + * r7 == syscall number + * r0 ... r6 == syscall arguments + * and returns the result in r0 + * Shuffle everything around appropriately. + * Note the 16 bytes that we pushed to save registers. + */ + mov r8, r0 /* copy signal_pending */ + mov r7, r1 /* syscall number */ + mov r0, r2 /* syscall args */ + mov r1, r3 + ldm r12, { r2, r3, r4, r5, r6 } - /* This next sequence of code works in conjunction with the - * rewind_if_safe_syscall_function(). If a signal is taken - * and the interrupted PC is anywhere between 'safe_syscall_start' - * and 'safe_syscall_end' then we rewind it to 'safe_syscall_start'. - * The code sequence must therefore be able to cope with this, and - * the syscall instruction must be the final one in the sequence. - */ + /* This next sequence of code works in conjunction with the + * rewind_if_safe_syscall_function(). If a signal is taken + * and the interrupted PC is anywhere between 'safe_syscall_start' + * and 'safe_syscall_end' then we rewind it to 'safe_syscall_start'. + * The code sequence must therefore be able to cope with this, and + * the syscall instruction must be the final one in the sequence. + */ safe_syscall_start: - /* if signal_pending is non-zero, don't do the call */ - ldr r12, [r8] /* signal_pending */ - tst r12, r12 - bne 1f - swi 0 + /* if signal_pending is non-zero, don't do the call */ + ldr r12, [r8] /* signal_pending */ + tst r12, r12 + bne 1f + swi 0 safe_syscall_end: - /* code path for having successfully executed the syscall */ - pop { r4, r5, r6, r7, r8, pc } + /* code path for having successfully executed the syscall */ + pop { r4, r5, r6, r7, r8, pc } 1: - /* code path when we didn't execute the syscall */ - ldr r0, =-TARGET_ERESTARTSYS - pop { r4, r5, r6, r7, r8, pc } - .fnend - .cfi_endproc + /* code path when we didn't execute the syscall */ + ldr r0, =-TARGET_ERESTARTSYS + pop { r4, r5, r6, r7, r8, pc } + .fnend + .cfi_endproc - .size safe_syscall_base, .-safe_syscall_base + .size safe_syscall_base, .-safe_syscall_base |