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linux/arch/alpha/kernel/entry.S

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Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
/*
* arch/alpha/kernel/entry.S
*
* Kernel entry-points.
*/
kbuild: alpha,x86_64 use generic asm-offsets.h support Delete obsolete stuff from arch makefiles Rename .h file to asm-offsets.h Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
2005-09-10 03:28:48 +08:00
#include <asm/asm-offsets.h>
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
#include <asm/thread_info.h>
#include <asm/pal.h>
#include <asm/errno.h>
#include <asm/unistd.h>
.text
.set noat
/* Stack offsets. */
#define SP_OFF 184
#define SWITCH_STACK_SIZE 320
/*
* This defines the normal kernel pt-regs layout.
*
* regs 9-15 preserved by C code
* regs 16-18 saved by PAL-code
* regs 29-30 saved and set up by PAL-code
* JRP - Save regs 16-18 in a special area of the stack, so that
* the palcode-provided values are available to the signal handler.
*/
#define SAVE_ALL \
subq $sp, SP_OFF, $sp; \
stq $0, 0($sp); \
stq $1, 8($sp); \
stq $2, 16($sp); \
stq $3, 24($sp); \
stq $4, 32($sp); \
stq $28, 144($sp); \
lda $2, alpha_mv; \
stq $5, 40($sp); \
stq $6, 48($sp); \
stq $7, 56($sp); \
stq $8, 64($sp); \
stq $19, 72($sp); \
stq $20, 80($sp); \
stq $21, 88($sp); \
ldq $2, HAE_CACHE($2); \
stq $22, 96($sp); \
stq $23, 104($sp); \
stq $24, 112($sp); \
stq $25, 120($sp); \
stq $26, 128($sp); \
stq $27, 136($sp); \
stq $2, 152($sp); \
stq $16, 160($sp); \
stq $17, 168($sp); \
stq $18, 176($sp)
#define RESTORE_ALL \
lda $19, alpha_mv; \
ldq $0, 0($sp); \
ldq $1, 8($sp); \
ldq $2, 16($sp); \
ldq $3, 24($sp); \
ldq $21, 152($sp); \
ldq $20, HAE_CACHE($19); \
ldq $4, 32($sp); \
ldq $5, 40($sp); \
ldq $6, 48($sp); \
ldq $7, 56($sp); \
subq $20, $21, $20; \
ldq $8, 64($sp); \
beq $20, 99f; \
ldq $20, HAE_REG($19); \
stq $21, HAE_CACHE($19); \
stq $21, 0($20); \
99:; \
ldq $19, 72($sp); \
ldq $20, 80($sp); \
ldq $21, 88($sp); \
ldq $22, 96($sp); \
ldq $23, 104($sp); \
ldq $24, 112($sp); \
ldq $25, 120($sp); \
ldq $26, 128($sp); \
ldq $27, 136($sp); \
ldq $28, 144($sp); \
addq $sp, SP_OFF, $sp
/*
* Non-syscall kernel entry points.
*/
.align 4
.globl entInt
.ent entInt
entInt:
SAVE_ALL
lda $8, 0x3fff
lda $26, ret_from_sys_call
bic $sp, $8, $8
mov $sp, $19
jsr $31, do_entInt
.end entInt
.align 4
.globl entArith
.ent entArith
entArith:
SAVE_ALL
lda $8, 0x3fff
lda $26, ret_from_sys_call
bic $sp, $8, $8
mov $sp, $18
jsr $31, do_entArith
.end entArith
.align 4
.globl entMM
.ent entMM
entMM:
SAVE_ALL
/* save $9 - $15 so the inline exception code can manipulate them. */
subq $sp, 56, $sp
stq $9, 0($sp)
stq $10, 8($sp)
stq $11, 16($sp)
stq $12, 24($sp)
stq $13, 32($sp)
stq $14, 40($sp)
stq $15, 48($sp)
addq $sp, 56, $19
/* handle the fault */
lda $8, 0x3fff
bic $sp, $8, $8
jsr $26, do_page_fault
/* reload the registers after the exception code played. */
ldq $9, 0($sp)
ldq $10, 8($sp)
ldq $11, 16($sp)
ldq $12, 24($sp)
ldq $13, 32($sp)
ldq $14, 40($sp)
ldq $15, 48($sp)
addq $sp, 56, $sp
/* finish up the syscall as normal. */
br ret_from_sys_call
.end entMM
.align 4
.globl entIF
.ent entIF
entIF:
SAVE_ALL
lda $8, 0x3fff
lda $26, ret_from_sys_call
bic $sp, $8, $8
mov $sp, $17
jsr $31, do_entIF
.end entIF
.align 4
.globl entUna
.ent entUna
entUna:
lda $sp, -256($sp)
stq $0, 0($sp)
ldq $0, 256($sp) /* get PS */
stq $1, 8($sp)
stq $2, 16($sp)
stq $3, 24($sp)
and $0, 8, $0 /* user mode? */
stq $4, 32($sp)
bne $0, entUnaUser /* yup -> do user-level unaligned fault */
stq $5, 40($sp)
stq $6, 48($sp)
stq $7, 56($sp)
stq $8, 64($sp)
stq $9, 72($sp)
stq $10, 80($sp)
stq $11, 88($sp)
stq $12, 96($sp)
stq $13, 104($sp)
stq $14, 112($sp)
stq $15, 120($sp)
/* 16-18 PAL-saved */
stq $19, 152($sp)
stq $20, 160($sp)
stq $21, 168($sp)
stq $22, 176($sp)
stq $23, 184($sp)
stq $24, 192($sp)
stq $25, 200($sp)
stq $26, 208($sp)
stq $27, 216($sp)
stq $28, 224($sp)
[PATCH] alpha: fix kernel alignment traps Pass in the pointer to the on-stack registers rather than using them directly as the arguments. Ivan noticed that I missed a spot when purging the registers as first stack parameter idiom. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-03 03:49:52 +08:00
mov $sp, $19
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
stq $gp, 232($sp)
lda $8, 0x3fff
stq $31, 248($sp)
bic $sp, $8, $8
jsr $26, do_entUna
ldq $0, 0($sp)
ldq $1, 8($sp)
ldq $2, 16($sp)
ldq $3, 24($sp)
ldq $4, 32($sp)
ldq $5, 40($sp)
ldq $6, 48($sp)
ldq $7, 56($sp)
ldq $8, 64($sp)
ldq $9, 72($sp)
ldq $10, 80($sp)
ldq $11, 88($sp)
ldq $12, 96($sp)
ldq $13, 104($sp)
ldq $14, 112($sp)
ldq $15, 120($sp)
/* 16-18 PAL-saved */
ldq $19, 152($sp)
ldq $20, 160($sp)
ldq $21, 168($sp)
ldq $22, 176($sp)
ldq $23, 184($sp)
ldq $24, 192($sp)
ldq $25, 200($sp)
ldq $26, 208($sp)
ldq $27, 216($sp)
ldq $28, 224($sp)
ldq $gp, 232($sp)
lda $sp, 256($sp)
call_pal PAL_rti
.end entUna
.align 4
.ent entUnaUser
entUnaUser:
ldq $0, 0($sp) /* restore original $0 */
lda $sp, 256($sp) /* pop entUna's stack frame */
SAVE_ALL /* setup normal kernel stack */
lda $sp, -56($sp)
stq $9, 0($sp)
stq $10, 8($sp)
stq $11, 16($sp)
stq $12, 24($sp)
stq $13, 32($sp)
stq $14, 40($sp)
stq $15, 48($sp)
lda $8, 0x3fff
addq $sp, 56, $19
bic $sp, $8, $8
jsr $26, do_entUnaUser
ldq $9, 0($sp)
ldq $10, 8($sp)
ldq $11, 16($sp)
ldq $12, 24($sp)
ldq $13, 32($sp)
ldq $14, 40($sp)
ldq $15, 48($sp)
lda $sp, 56($sp)
br ret_from_sys_call
.end entUnaUser
.align 4
.globl entDbg
.ent entDbg
entDbg:
SAVE_ALL
lda $8, 0x3fff
lda $26, ret_from_sys_call
bic $sp, $8, $8
mov $sp, $16
jsr $31, do_entDbg
.end entDbg
/*
* The system call entry point is special. Most importantly, it looks
* like a function call to userspace as far as clobbered registers. We
* do preserve the argument registers (for syscall restarts) and $26
* (for leaf syscall functions).
*
* So much for theory. We don't take advantage of this yet.
*
* Note that a0-a2 are not saved by PALcode as with the other entry points.
*/
.align 4
.globl entSys
.globl ret_from_sys_call
.ent entSys
entSys:
SAVE_ALL
lda $8, 0x3fff
bic $sp, $8, $8
lda $4, NR_SYSCALLS($31)
stq $16, SP_OFF+24($sp)
lda $5, sys_call_table
lda $27, sys_ni_syscall
cmpult $0, $4, $4
ldl $3, TI_FLAGS($8)
stq $17, SP_OFF+32($sp)
s8addq $0, $5, $5
stq $18, SP_OFF+40($sp)
blbs $3, strace
beq $4, 1f
ldq $27, 0($5)
1: jsr $26, ($27), alpha_ni_syscall
ldgp $gp, 0($26)
blt $0, $syscall_error /* the call failed */
stq $0, 0($sp)
stq $31, 72($sp) /* a3=0 => no error */
.align 4
ret_from_sys_call:
alpha: get rid of switch_stack argument of do_work_pending() ... and now the asm glue side of that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 11:50:59 +08:00
cmovne $26, 0, $18 /* $18 = 0 => non-restartable */
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
ldq $0, SP_OFF($sp)
and $0, 8, $0
alpha: fix hae_cache race in RESTORE_ALL We want interrupts disabled on all paths leading to RESTORE_ALL; otherwise, we are risking an IRQ coming between the updates of alpha_mv->hae_cache and *alpha_mv->hae_register and set_hae() within the IRQ getting badly confused. RESTORE_ALL used to play with disabling IRQ itself, but that got removed back in 2002, without making sure we had them disabled on all paths. It's cheaper to make sure we have them disabled than to revert to original variant... Remove the detritus left from that commit back in 2002; we used to need a reload of $0 and $1 since swpipl would change those, but doing that had become pointless when we stopped doing swpipl in there... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-26 04:07:14 +08:00
beq $0, ret_to_kernel
alpha: deal with multiple simultaneously pending signals Unlike the other targets, alpha sets _one_ sigframe and buggers off until the next syscall/interrupt, even if more signals are pending. It leads to quite a few unpleasant inconsistencies, starting with SIGSEGV potentially arriving not where it should and including e.g. mess with sigsuspend(); consider two pending signals blocked until sigsuspend() unblocks them. We pick the first one; then, if we are hit by interrupt while in the handler, we process the second one as well. If we are not, and if no syscalls had been made, we get out of the first handler and leave the second signal pending; normally sigreturn() would've picked it anyway, but here it starts with restoring the original mask and voila - the second signal is blocked again. On everything else we get both delivered consistently. It's actually easy to fix; the only thing to watch out for is prevention of double syscall restart. Fortunately, the idea I've nicked from arm fix by rmk works just fine... Testcase demonstrating the behaviour in question; on alpha we get one or both flags set (usually one), on everything else both are always set. #include <signal.h> #include <stdio.h> int had1, had2; void f1(int sig) { had1 = 1; } void f2(int sig) { had2 = 1; } main() { sigset_t set1, set2; sigemptyset(&set1); sigemptyset(&set2); sigaddset(&set2, 1); sigaddset(&set2, 2); signal(1, f1); signal(2, f2); sigprocmask(SIG_SETMASK, &set2, NULL); raise(1); raise(2); sigsuspend(&set1); printf("had1:%d had2:%d\n", had1, had2); } Tested-by: Michael Cree <mcree@orcon.net.nz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matt Turner <mattst88@gmail.com>
2010-09-18 20:42:27 +08:00
ret_to_user:
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
/* Make sure need_resched and sigpending don't change between
sampling and the rti. */
lda $16, 7
call_pal PAL_swpipl
alpha: get rid of switch_stack argument of do_work_pending() ... and now the asm glue side of that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 11:50:59 +08:00
ldl $17, TI_FLAGS($8)
and $17, _TIF_WORK_MASK, $2
alpha: deal with multiple simultaneously pending signals Unlike the other targets, alpha sets _one_ sigframe and buggers off until the next syscall/interrupt, even if more signals are pending. It leads to quite a few unpleasant inconsistencies, starting with SIGSEGV potentially arriving not where it should and including e.g. mess with sigsuspend(); consider two pending signals blocked until sigsuspend() unblocks them. We pick the first one; then, if we are hit by interrupt while in the handler, we process the second one as well. If we are not, and if no syscalls had been made, we get out of the first handler and leave the second signal pending; normally sigreturn() would've picked it anyway, but here it starts with restoring the original mask and voila - the second signal is blocked again. On everything else we get both delivered consistently. It's actually easy to fix; the only thing to watch out for is prevention of double syscall restart. Fortunately, the idea I've nicked from arm fix by rmk works just fine... Testcase demonstrating the behaviour in question; on alpha we get one or both flags set (usually one), on everything else both are always set. #include <signal.h> #include <stdio.h> int had1, had2; void f1(int sig) { had1 = 1; } void f2(int sig) { had2 = 1; } main() { sigset_t set1, set2; sigemptyset(&set1); sigemptyset(&set2); sigaddset(&set2, 1); sigaddset(&set2, 2); signal(1, f1); signal(2, f2); sigprocmask(SIG_SETMASK, &set2, NULL); raise(1); raise(2); sigsuspend(&set1); printf("had1:%d had2:%d\n", had1, had2); } Tested-by: Michael Cree <mcree@orcon.net.nz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matt Turner <mattst88@gmail.com>
2010-09-18 20:42:27 +08:00
bne $2, work_pending
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
restore_all:
RESTORE_ALL
call_pal PAL_rti
alpha: fix hae_cache race in RESTORE_ALL We want interrupts disabled on all paths leading to RESTORE_ALL; otherwise, we are risking an IRQ coming between the updates of alpha_mv->hae_cache and *alpha_mv->hae_register and set_hae() within the IRQ getting badly confused. RESTORE_ALL used to play with disabling IRQ itself, but that got removed back in 2002, without making sure we had them disabled on all paths. It's cheaper to make sure we have them disabled than to revert to original variant... Remove the detritus left from that commit back in 2002; we used to need a reload of $0 and $1 since swpipl would change those, but doing that had become pointless when we stopped doing swpipl in there... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-26 04:07:14 +08:00
ret_to_kernel:
lda $16, 7
call_pal PAL_swpipl
br restore_all
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
.align 3
$syscall_error:
/*
* Some system calls (e.g., ptrace) can return arbitrary
* values which might normally be mistaken as error numbers.
* Those functions must zero $0 (v0) directly in the stack
* frame to indicate that a negative return value wasn't an
* error number..
*/
alpha: get rid of switch_stack argument of do_work_pending() ... and now the asm glue side of that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 11:50:59 +08:00
ldq $18, 0($sp) /* old syscall nr (zero if success) */
beq $18, $ret_success
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
alpha: get rid of switch_stack argument of do_work_pending() ... and now the asm glue side of that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 11:50:59 +08:00
ldq $19, 72($sp) /* .. and this a3 */
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
subq $31, $0, $0 /* with error in v0 */
addq $31, 1, $1 /* set a3 for errno return */
stq $0, 0($sp)
mov $31, $26 /* tell "ret_from_sys_call" we can restart */
stq $1, 72($sp) /* a3 for return */
br ret_from_sys_call
$ret_success:
stq $0, 0($sp)
stq $31, 72($sp) /* a3=0 => no error */
br ret_from_sys_call
.end entSys
/*
* Do all cleanup when returning from all interrupts and system calls.
*
* Arguments:
* $8: current.
alpha: get rid of switch_stack argument of do_work_pending() ... and now the asm glue side of that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 11:50:59 +08:00
* $17: TI_FLAGS.
* $18: The old syscall number, or zero if this is not a return
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
* from a syscall that errored and is possibly restartable.
alpha: get rid of switch_stack argument of do_work_pending() ... and now the asm glue side of that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 11:50:59 +08:00
* $19: The old a3 value
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
*/
.align 4
.ent work_pending
work_pending:
alpha: get rid of switch_stack argument of do_work_pending() ... and now the asm glue side of that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 11:50:59 +08:00
and $17, _TIF_NOTIFY_RESUME | _TIF_SIGPENDING, $2
alpha: simplify TIF_NEED_RESCHED handling In case we have both NEED_RESCHED and SIGPENDING/NOTIFY_RESUME, handle the latter first. We'll get to original priorities in the next commit, but now that allows to simplify the treatment of NEED_RESCHED-only case nicely. Namely, now there no need to preserve the data for restarts across the call of schedule() in $work_resched; we can get there only if we had either returned from syscall without SIGPENDING (in which case we should've had no restart-worthy return value and want no restarts) or already got through do_notify_resume() call (in which case we want no restarts anymore). So we can just slap 0 into $19 instead of preserving it (and $20). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-06 06:08:40 +08:00
bne $2, $work_notifysig
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
$work_resched:
alpha: simplify TIF_NEED_RESCHED handling In case we have both NEED_RESCHED and SIGPENDING/NOTIFY_RESUME, handle the latter first. We'll get to original priorities in the next commit, but now that allows to simplify the treatment of NEED_RESCHED-only case nicely. Namely, now there no need to preserve the data for restarts across the call of schedule() in $work_resched; we can get there only if we had either returned from syscall without SIGPENDING (in which case we should've had no restart-worthy return value and want no restarts) or already got through do_notify_resume() call (in which case we want no restarts anymore). So we can just slap 0 into $19 instead of preserving it (and $20). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-06 06:08:40 +08:00
/*
* We can get here only if we returned from syscall without SIGPENDING
* or got through work_notifysig already. Either case means no syscall
alpha: get rid of switch_stack argument of do_work_pending() ... and now the asm glue side of that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 11:50:59 +08:00
* restarts for us, so let $18 and $19 burn.
alpha: simplify TIF_NEED_RESCHED handling In case we have both NEED_RESCHED and SIGPENDING/NOTIFY_RESUME, handle the latter first. We'll get to original priorities in the next commit, but now that allows to simplify the treatment of NEED_RESCHED-only case nicely. Namely, now there no need to preserve the data for restarts across the call of schedule() in $work_resched; we can get there only if we had either returned from syscall without SIGPENDING (in which case we should've had no restart-worthy return value and want no restarts) or already got through do_notify_resume() call (in which case we want no restarts anymore). So we can just slap 0 into $19 instead of preserving it (and $20). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-06 06:08:40 +08:00
*/
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
jsr $26, schedule
alpha: get rid of switch_stack argument of do_work_pending() ... and now the asm glue side of that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 11:50:59 +08:00
mov 0, $18
alpha: simplify TIF_NEED_RESCHED handling In case we have both NEED_RESCHED and SIGPENDING/NOTIFY_RESUME, handle the latter first. We'll get to original priorities in the next commit, but now that allows to simplify the treatment of NEED_RESCHED-only case nicely. Namely, now there no need to preserve the data for restarts across the call of schedule() in $work_resched; we can get there only if we had either returned from syscall without SIGPENDING (in which case we should've had no restart-worthy return value and want no restarts) or already got through do_notify_resume() call (in which case we want no restarts anymore). So we can just slap 0 into $19 instead of preserving it (and $20). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-06 06:08:40 +08:00
br ret_to_user
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
$work_notifysig:
alpha: support new syscalls Some of the new syscalls require supporting TIF_RESTORE_SIGMASK. Signed-off-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-30 07:03:28 +08:00
mov $sp, $16
alpha: deal with multiple simultaneously pending signals Unlike the other targets, alpha sets _one_ sigframe and buggers off until the next syscall/interrupt, even if more signals are pending. It leads to quite a few unpleasant inconsistencies, starting with SIGSEGV potentially arriving not where it should and including e.g. mess with sigsuspend(); consider two pending signals blocked until sigsuspend() unblocks them. We pick the first one; then, if we are hit by interrupt while in the handler, we process the second one as well. If we are not, and if no syscalls had been made, we get out of the first handler and leave the second signal pending; normally sigreturn() would've picked it anyway, but here it starts with restoring the original mask and voila - the second signal is blocked again. On everything else we get both delivered consistently. It's actually easy to fix; the only thing to watch out for is prevention of double syscall restart. Fortunately, the idea I've nicked from arm fix by rmk works just fine... Testcase demonstrating the behaviour in question; on alpha we get one or both flags set (usually one), on everything else both are always set. #include <signal.h> #include <stdio.h> int had1, had2; void f1(int sig) { had1 = 1; } void f2(int sig) { had2 = 1; } main() { sigset_t set1, set2; sigemptyset(&set1); sigemptyset(&set2); sigaddset(&set2, 1); sigaddset(&set2, 2); signal(1, f1); signal(2, f2); sigprocmask(SIG_SETMASK, &set2, NULL); raise(1); raise(2); sigsuspend(&set1); printf("had1:%d had2:%d\n", had1, had2); } Tested-by: Michael Cree <mcree@orcon.net.nz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matt Turner <mattst88@gmail.com>
2010-09-18 20:42:27 +08:00
bsr $1, do_switch_stack
alpha: take SIGPENDING/NOTIFY_RESUME loop into signal.c Turn the slow side of work_pending into C function, including all the looping. What we get out of that: * we do _not_ call get_signal_to_deliver() with IRQs disabled anymore * no need to save/restore volatiles on each pass if there turns to be more than one (unlikely, but still) * all double-restart prevention is in C now. * glue gets simpler. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-06 06:30:34 +08:00
jsr $26, do_work_pending
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
bsr $1, undo_switch_stack
alpha: take SIGPENDING/NOTIFY_RESUME loop into signal.c Turn the slow side of work_pending into C function, including all the looping. What we get out of that: * we do _not_ call get_signal_to_deliver() with IRQs disabled anymore * no need to save/restore volatiles on each pass if there turns to be more than one (unlikely, but still) * all double-restart prevention is in C now. * glue gets simpler. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-06 06:30:34 +08:00
br restore_all
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
.end work_pending
/*
* PTRACE syscall handler
*/
.align 4
.ent strace
strace:
/* set up signal stack, call syscall_trace */
bsr $1, do_switch_stack
alpha: don't open-code trace_report_syscall_{enter,exit} Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-27 09:44:21 +08:00
jsr $26, syscall_trace_enter /* returns the syscall number */
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
bsr $1, undo_switch_stack
alpha: don't open-code trace_report_syscall_{enter,exit} Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-27 09:44:21 +08:00
/* get the arguments back.. */
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
ldq $16, SP_OFF+24($sp)
ldq $17, SP_OFF+32($sp)
ldq $18, SP_OFF+40($sp)
ldq $19, 72($sp)
ldq $20, 80($sp)
ldq $21, 88($sp)
/* get the system call pointer.. */
lda $1, NR_SYSCALLS($31)
lda $2, sys_call_table
lda $27, alpha_ni_syscall
cmpult $0, $1, $1
s8addq $0, $2, $2
beq $1, 1f
ldq $27, 0($2)
1: jsr $26, ($27), sys_gettimeofday
alpha: fix a 14 years old bug in sigreturn tracing The way sigreturn() is implemented on alpha breaks PTRACE_SYSCALL, all way back to 1.3.95 when alpha has grown PTRACE_SYSCALL support. What happens is direct return to ret_from_syscall, in order to bypass mangling of a3 (error indicator) and prevent other mutilations of registers (e.g. by syscall restart). That's fine, but... the entire TIF_SYSCALL_TRACE codepath is kept separate on alpha and post-syscall stopping/notifying the tracer is after the syscall. And the normal path we are forcibly switching to doesn't have it. So we end up with *one* stop in traced sigreturn() vs. two in other syscalls. And yes, strace is visibly broken by that; try to strace the following #include <signal.h> #include <stdio.h> void f(int sig) {} main() { signal(SIGHUP, f); raise(SIGHUP); write(1, "eeeek\n", 6); } and watch the show. The close(1) = 405 in the end of strace output is coming from return value of write() (6 == __NR_close on alpha) and syscall number of exit_group() (__NR_exit_group == 405 there). The fix is fairly simple - the only thing we end up missing is the call of syscall_trace() and we can tell whether we'd been called from the SYSCALL_TRACE path by checking ra value. Since we are setting the switch_stack up (that's what sys_sigreturn() does), we have the right environment for calling syscall_trace() - just before we call undo_switch_stack() and return. Since undo_switch_stack() will overwrite s0 anyway, we can use it to store the result of "has it been called from SYSCALL_TRACE path?" check. The same thing applies in rt_sigreturn(). Tested-by: Michael Cree <mcree@orcon.net.nz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matt Turner <mattst88@gmail.com>
2010-09-18 20:41:16 +08:00
ret_from_straced:
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
ldgp $gp, 0($26)
/* check return.. */
blt $0, $strace_error /* the call failed */
stq $31, 72($sp) /* a3=0 => no error */
$strace_success:
stq $0, 0($sp) /* save return value */
bsr $1, do_switch_stack
alpha: don't open-code trace_report_syscall_{enter,exit} Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-27 09:44:21 +08:00
jsr $26, syscall_trace_leave
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
bsr $1, undo_switch_stack
br $31, ret_from_sys_call
.align 3
$strace_error:
alpha: get rid of switch_stack argument of do_work_pending() ... and now the asm glue side of that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 11:50:59 +08:00
ldq $18, 0($sp) /* old syscall nr (zero if success) */
beq $18, $strace_success
ldq $19, 72($sp) /* .. and this a3 */
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
subq $31, $0, $0 /* with error in v0 */
addq $31, 1, $1 /* set a3 for errno return */
stq $0, 0($sp)
stq $1, 72($sp) /* a3 for return */
bsr $1, do_switch_stack
alpha: get rid of switch_stack argument of do_work_pending() ... and now the asm glue side of that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 11:50:59 +08:00
mov $18, $9 /* save old syscall number */
mov $19, $10 /* save old a3 */
alpha: don't open-code trace_report_syscall_{enter,exit} Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-27 09:44:21 +08:00
jsr $26, syscall_trace_leave
alpha: get rid of switch_stack argument of do_work_pending() ... and now the asm glue side of that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 11:50:59 +08:00
mov $9, $18
mov $10, $19
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
bsr $1, undo_switch_stack
mov $31, $26 /* tell "ret_from_sys_call" we can restart */
br ret_from_sys_call
.end strace
/*
* Save and restore the switch stack -- aka the balance of the user context.
*/
.align 4
.ent do_switch_stack
do_switch_stack:
lda $sp, -SWITCH_STACK_SIZE($sp)
stq $9, 0($sp)
stq $10, 8($sp)
stq $11, 16($sp)
stq $12, 24($sp)
stq $13, 32($sp)
stq $14, 40($sp)
stq $15, 48($sp)
stq $26, 56($sp)
stt $f0, 64($sp)
stt $f1, 72($sp)
stt $f2, 80($sp)
stt $f3, 88($sp)
stt $f4, 96($sp)
stt $f5, 104($sp)
stt $f6, 112($sp)
stt $f7, 120($sp)
stt $f8, 128($sp)
stt $f9, 136($sp)
stt $f10, 144($sp)
stt $f11, 152($sp)
stt $f12, 160($sp)
stt $f13, 168($sp)
stt $f14, 176($sp)
stt $f15, 184($sp)
stt $f16, 192($sp)
stt $f17, 200($sp)
stt $f18, 208($sp)
stt $f19, 216($sp)
stt $f20, 224($sp)
stt $f21, 232($sp)
stt $f22, 240($sp)
stt $f23, 248($sp)
stt $f24, 256($sp)
stt $f25, 264($sp)
stt $f26, 272($sp)
stt $f27, 280($sp)
mf_fpcr $f0 # get fpcr
stt $f28, 288($sp)
stt $f29, 296($sp)
stt $f30, 304($sp)
stt $f0, 312($sp) # save fpcr in slot of $f31
ldt $f0, 64($sp) # dont let "do_switch_stack" change fp state.
ret $31, ($1), 1
.end do_switch_stack
.align 4
.ent undo_switch_stack
undo_switch_stack:
ldq $9, 0($sp)
ldq $10, 8($sp)
ldq $11, 16($sp)
ldq $12, 24($sp)
ldq $13, 32($sp)
ldq $14, 40($sp)
ldq $15, 48($sp)
ldq $26, 56($sp)
ldt $f30, 312($sp) # get saved fpcr
ldt $f0, 64($sp)
ldt $f1, 72($sp)
ldt $f2, 80($sp)
ldt $f3, 88($sp)
mt_fpcr $f30 # install saved fpcr
ldt $f4, 96($sp)
ldt $f5, 104($sp)
ldt $f6, 112($sp)
ldt $f7, 120($sp)
ldt $f8, 128($sp)
ldt $f9, 136($sp)
ldt $f10, 144($sp)
ldt $f11, 152($sp)
ldt $f12, 160($sp)
ldt $f13, 168($sp)
ldt $f14, 176($sp)
ldt $f15, 184($sp)
ldt $f16, 192($sp)
ldt $f17, 200($sp)
ldt $f18, 208($sp)
ldt $f19, 216($sp)
ldt $f20, 224($sp)
ldt $f21, 232($sp)
ldt $f22, 240($sp)
ldt $f23, 248($sp)
ldt $f24, 256($sp)
ldt $f25, 264($sp)
ldt $f26, 272($sp)
ldt $f27, 280($sp)
ldt $f28, 288($sp)
ldt $f29, 296($sp)
ldt $f30, 304($sp)
lda $sp, SWITCH_STACK_SIZE($sp)
ret $31, ($1), 1
.end undo_switch_stack
/*
* The meat of the context switch code.
*/
.align 4
.globl alpha_switch_to
.ent alpha_switch_to
alpha_switch_to:
.prologue 0
bsr $1, do_switch_stack
call_pal PAL_swpctx
lda $8, 0x3fff
bsr $1, undo_switch_stack
bic $sp, $8, $8
mov $17, $0
ret
.end alpha_switch_to
/*
* New processes begin life here.
*/
.globl ret_from_fork
.align 4
.ent ret_from_fork
ret_from_fork:
lda $26, ret_from_sys_call
mov $17, $16
jmp $31, schedule_tail
.end ret_from_fork
/*
alpha: switch to generic kernel_thread() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-10 10:03:42 +08:00
* ... and new kernel threads - here
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
*/
.align 4
alpha: switch to generic kernel_thread() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-10 10:03:42 +08:00
.globl ret_from_kernel_thread
.ent ret_from_kernel_thread
ret_from_kernel_thread:
mov $17, $16
jsr $26, schedule_tail
mov $9, $27
mov $10, $16
jsr $26, ($9)
alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 10:22:52 +08:00
mov $31, $19 /* to disable syscall restarts */
br $31, ret_to_user
alpha: switch to saner kernel_execve() semantics Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 11:12:01 +08:00
.end ret_from_kernel_thread
alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 10:22:52 +08:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
/*
* Special system calls. Most of these are special in that they either
* have to play switch_stack games or in some way use the pt_regs struct.
*/
.align 4
.globl sys_fork
.ent sys_fork
sys_fork:
.prologue 0
mov $sp, $21
bsr $1, do_switch_stack
bis $31, SIGCHLD, $16
mov $31, $17
mov $31, $18
mov $31, $19
mov $31, $20
jsr $26, alpha_clone
bsr $1, undo_switch_stack
ret
.end sys_fork
.align 4
.globl sys_clone
.ent sys_clone
sys_clone:
.prologue 0
mov $sp, $21
bsr $1, do_switch_stack
/* $16, $17, $18, $19, $20 come from the user. */
jsr $26, alpha_clone
bsr $1, undo_switch_stack
ret
.end sys_clone
.align 4
.globl sys_vfork
.ent sys_vfork
sys_vfork:
.prologue 0
mov $sp, $16
bsr $1, do_switch_stack
jsr $26, alpha_vfork
bsr $1, undo_switch_stack
ret
.end sys_vfork
.align 4
.globl sys_sigreturn
.ent sys_sigreturn
sys_sigreturn:
.prologue 0
alpha: fix a 14 years old bug in sigreturn tracing The way sigreturn() is implemented on alpha breaks PTRACE_SYSCALL, all way back to 1.3.95 when alpha has grown PTRACE_SYSCALL support. What happens is direct return to ret_from_syscall, in order to bypass mangling of a3 (error indicator) and prevent other mutilations of registers (e.g. by syscall restart). That's fine, but... the entire TIF_SYSCALL_TRACE codepath is kept separate on alpha and post-syscall stopping/notifying the tracer is after the syscall. And the normal path we are forcibly switching to doesn't have it. So we end up with *one* stop in traced sigreturn() vs. two in other syscalls. And yes, strace is visibly broken by that; try to strace the following #include <signal.h> #include <stdio.h> void f(int sig) {} main() { signal(SIGHUP, f); raise(SIGHUP); write(1, "eeeek\n", 6); } and watch the show. The close(1) = 405 in the end of strace output is coming from return value of write() (6 == __NR_close on alpha) and syscall number of exit_group() (__NR_exit_group == 405 there). The fix is fairly simple - the only thing we end up missing is the call of syscall_trace() and we can tell whether we'd been called from the SYSCALL_TRACE path by checking ra value. Since we are setting the switch_stack up (that's what sys_sigreturn() does), we have the right environment for calling syscall_trace() - just before we call undo_switch_stack() and return. Since undo_switch_stack() will overwrite s0 anyway, we can use it to store the result of "has it been called from SYSCALL_TRACE path?" check. The same thing applies in rt_sigreturn(). Tested-by: Michael Cree <mcree@orcon.net.nz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matt Turner <mattst88@gmail.com>
2010-09-18 20:41:16 +08:00
lda $9, ret_from_straced
cmpult $26, $9, $9
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
mov $sp, $17
lda $18, -SWITCH_STACK_SIZE($sp)
lda $sp, -SWITCH_STACK_SIZE($sp)
jsr $26, do_sigreturn
alpha: fix a 14 years old bug in sigreturn tracing The way sigreturn() is implemented on alpha breaks PTRACE_SYSCALL, all way back to 1.3.95 when alpha has grown PTRACE_SYSCALL support. What happens is direct return to ret_from_syscall, in order to bypass mangling of a3 (error indicator) and prevent other mutilations of registers (e.g. by syscall restart). That's fine, but... the entire TIF_SYSCALL_TRACE codepath is kept separate on alpha and post-syscall stopping/notifying the tracer is after the syscall. And the normal path we are forcibly switching to doesn't have it. So we end up with *one* stop in traced sigreturn() vs. two in other syscalls. And yes, strace is visibly broken by that; try to strace the following #include <signal.h> #include <stdio.h> void f(int sig) {} main() { signal(SIGHUP, f); raise(SIGHUP); write(1, "eeeek\n", 6); } and watch the show. The close(1) = 405 in the end of strace output is coming from return value of write() (6 == __NR_close on alpha) and syscall number of exit_group() (__NR_exit_group == 405 there). The fix is fairly simple - the only thing we end up missing is the call of syscall_trace() and we can tell whether we'd been called from the SYSCALL_TRACE path by checking ra value. Since we are setting the switch_stack up (that's what sys_sigreturn() does), we have the right environment for calling syscall_trace() - just before we call undo_switch_stack() and return. Since undo_switch_stack() will overwrite s0 anyway, we can use it to store the result of "has it been called from SYSCALL_TRACE path?" check. The same thing applies in rt_sigreturn(). Tested-by: Michael Cree <mcree@orcon.net.nz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matt Turner <mattst88@gmail.com>
2010-09-18 20:41:16 +08:00
bne $9, 1f
alpha: don't open-code trace_report_syscall_{enter,exit} Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-27 09:44:21 +08:00
jsr $26, syscall_trace_leave
alpha: fix a 14 years old bug in sigreturn tracing The way sigreturn() is implemented on alpha breaks PTRACE_SYSCALL, all way back to 1.3.95 when alpha has grown PTRACE_SYSCALL support. What happens is direct return to ret_from_syscall, in order to bypass mangling of a3 (error indicator) and prevent other mutilations of registers (e.g. by syscall restart). That's fine, but... the entire TIF_SYSCALL_TRACE codepath is kept separate on alpha and post-syscall stopping/notifying the tracer is after the syscall. And the normal path we are forcibly switching to doesn't have it. So we end up with *one* stop in traced sigreturn() vs. two in other syscalls. And yes, strace is visibly broken by that; try to strace the following #include <signal.h> #include <stdio.h> void f(int sig) {} main() { signal(SIGHUP, f); raise(SIGHUP); write(1, "eeeek\n", 6); } and watch the show. The close(1) = 405 in the end of strace output is coming from return value of write() (6 == __NR_close on alpha) and syscall number of exit_group() (__NR_exit_group == 405 there). The fix is fairly simple - the only thing we end up missing is the call of syscall_trace() and we can tell whether we'd been called from the SYSCALL_TRACE path by checking ra value. Since we are setting the switch_stack up (that's what sys_sigreturn() does), we have the right environment for calling syscall_trace() - just before we call undo_switch_stack() and return. Since undo_switch_stack() will overwrite s0 anyway, we can use it to store the result of "has it been called from SYSCALL_TRACE path?" check. The same thing applies in rt_sigreturn(). Tested-by: Michael Cree <mcree@orcon.net.nz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matt Turner <mattst88@gmail.com>
2010-09-18 20:41:16 +08:00
1: br $1, undo_switch_stack
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
br ret_from_sys_call
.end sys_sigreturn
.align 4
.globl sys_rt_sigreturn
.ent sys_rt_sigreturn
sys_rt_sigreturn:
.prologue 0
alpha: fix a 14 years old bug in sigreturn tracing The way sigreturn() is implemented on alpha breaks PTRACE_SYSCALL, all way back to 1.3.95 when alpha has grown PTRACE_SYSCALL support. What happens is direct return to ret_from_syscall, in order to bypass mangling of a3 (error indicator) and prevent other mutilations of registers (e.g. by syscall restart). That's fine, but... the entire TIF_SYSCALL_TRACE codepath is kept separate on alpha and post-syscall stopping/notifying the tracer is after the syscall. And the normal path we are forcibly switching to doesn't have it. So we end up with *one* stop in traced sigreturn() vs. two in other syscalls. And yes, strace is visibly broken by that; try to strace the following #include <signal.h> #include <stdio.h> void f(int sig) {} main() { signal(SIGHUP, f); raise(SIGHUP); write(1, "eeeek\n", 6); } and watch the show. The close(1) = 405 in the end of strace output is coming from return value of write() (6 == __NR_close on alpha) and syscall number of exit_group() (__NR_exit_group == 405 there). The fix is fairly simple - the only thing we end up missing is the call of syscall_trace() and we can tell whether we'd been called from the SYSCALL_TRACE path by checking ra value. Since we are setting the switch_stack up (that's what sys_sigreturn() does), we have the right environment for calling syscall_trace() - just before we call undo_switch_stack() and return. Since undo_switch_stack() will overwrite s0 anyway, we can use it to store the result of "has it been called from SYSCALL_TRACE path?" check. The same thing applies in rt_sigreturn(). Tested-by: Michael Cree <mcree@orcon.net.nz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matt Turner <mattst88@gmail.com>
2010-09-18 20:41:16 +08:00
lda $9, ret_from_straced
cmpult $26, $9, $9
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
mov $sp, $17
lda $18, -SWITCH_STACK_SIZE($sp)
lda $sp, -SWITCH_STACK_SIZE($sp)
jsr $26, do_rt_sigreturn
alpha: fix a 14 years old bug in sigreturn tracing The way sigreturn() is implemented on alpha breaks PTRACE_SYSCALL, all way back to 1.3.95 when alpha has grown PTRACE_SYSCALL support. What happens is direct return to ret_from_syscall, in order to bypass mangling of a3 (error indicator) and prevent other mutilations of registers (e.g. by syscall restart). That's fine, but... the entire TIF_SYSCALL_TRACE codepath is kept separate on alpha and post-syscall stopping/notifying the tracer is after the syscall. And the normal path we are forcibly switching to doesn't have it. So we end up with *one* stop in traced sigreturn() vs. two in other syscalls. And yes, strace is visibly broken by that; try to strace the following #include <signal.h> #include <stdio.h> void f(int sig) {} main() { signal(SIGHUP, f); raise(SIGHUP); write(1, "eeeek\n", 6); } and watch the show. The close(1) = 405 in the end of strace output is coming from return value of write() (6 == __NR_close on alpha) and syscall number of exit_group() (__NR_exit_group == 405 there). The fix is fairly simple - the only thing we end up missing is the call of syscall_trace() and we can tell whether we'd been called from the SYSCALL_TRACE path by checking ra value. Since we are setting the switch_stack up (that's what sys_sigreturn() does), we have the right environment for calling syscall_trace() - just before we call undo_switch_stack() and return. Since undo_switch_stack() will overwrite s0 anyway, we can use it to store the result of "has it been called from SYSCALL_TRACE path?" check. The same thing applies in rt_sigreturn(). Tested-by: Michael Cree <mcree@orcon.net.nz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matt Turner <mattst88@gmail.com>
2010-09-18 20:41:16 +08:00
bne $9, 1f
alpha: don't open-code trace_report_syscall_{enter,exit} Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-27 09:44:21 +08:00
jsr $26, syscall_trace_leave
alpha: fix a 14 years old bug in sigreturn tracing The way sigreturn() is implemented on alpha breaks PTRACE_SYSCALL, all way back to 1.3.95 when alpha has grown PTRACE_SYSCALL support. What happens is direct return to ret_from_syscall, in order to bypass mangling of a3 (error indicator) and prevent other mutilations of registers (e.g. by syscall restart). That's fine, but... the entire TIF_SYSCALL_TRACE codepath is kept separate on alpha and post-syscall stopping/notifying the tracer is after the syscall. And the normal path we are forcibly switching to doesn't have it. So we end up with *one* stop in traced sigreturn() vs. two in other syscalls. And yes, strace is visibly broken by that; try to strace the following #include <signal.h> #include <stdio.h> void f(int sig) {} main() { signal(SIGHUP, f); raise(SIGHUP); write(1, "eeeek\n", 6); } and watch the show. The close(1) = 405 in the end of strace output is coming from return value of write() (6 == __NR_close on alpha) and syscall number of exit_group() (__NR_exit_group == 405 there). The fix is fairly simple - the only thing we end up missing is the call of syscall_trace() and we can tell whether we'd been called from the SYSCALL_TRACE path by checking ra value. Since we are setting the switch_stack up (that's what sys_sigreturn() does), we have the right environment for calling syscall_trace() - just before we call undo_switch_stack() and return. Since undo_switch_stack() will overwrite s0 anyway, we can use it to store the result of "has it been called from SYSCALL_TRACE path?" check. The same thing applies in rt_sigreturn(). Tested-by: Michael Cree <mcree@orcon.net.nz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Matt Turner <mattst88@gmail.com>
2010-09-18 20:41:16 +08:00
1: br $1, undo_switch_stack
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
br ret_from_sys_call
.end sys_rt_sigreturn
.align 4
.globl alpha_ni_syscall
.ent alpha_ni_syscall
alpha_ni_syscall:
.prologue 0
/* Special because it also implements overflow handling via
syscall number 0. And if you recall, zero is a special
trigger for "not an error". Store large non-zero there. */
lda $0, -ENOSYS
unop
stq $0, 0($sp)
ret
.end alpha_ni_syscall
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