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| author | Dmitry Safonov <dima@arista.com> | 2020-06-08 21:31:51 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 09:39:12 -0700 |
| commit | de985dd50158fedde5f2916c1bcf949a0acf5cd0 (patch) | |
| tree | ef2db42ff60f1cef37189a54fff6ddcbc3b58db6 /arch/unicore32/lib/backtrace.S | |
| parent | ee1e99009e914e4150774f5a717c179545c7699e (diff) | |
| download | linux-de985dd50158fedde5f2916c1bcf949a0acf5cd0.tar.bz2 | |
unicore32: add loglvl to c_backtrace()
Currently, the log-level of show_stack() depends on a platform
realization. It creates situations where the headers are printed with
lower log level or higher than the stacktrace (depending on a platform or
user).
Furthermore, it forces the logic decision from user to an architecture
side. In result, some users as sysrq/kdb/etc are doing tricks with
temporary rising console_loglevel while printing their messages. And in
result it not only may print unwanted messages from other CPUs, but also
omit printing at all in the unlucky case where the printk() was deferred.
Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier
approach than introducing more printk buffers. Also, it will consolidate
printings with headers.
Add log level parameter to c_backtrace() as a preparation for introducing
show_stack_loglvl()
[1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Link: http://lkml.kernel.org/r/20200418201944.482088-39-dima@arista.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/unicore32/lib/backtrace.S')
| -rw-r--r-- | arch/unicore32/lib/backtrace.S | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/arch/unicore32/lib/backtrace.S b/arch/unicore32/lib/backtrace.S index f303671e2a4e..6221944b81f3 100644 --- a/arch/unicore32/lib/backtrace.S +++ b/arch/unicore32/lib/backtrace.S @@ -16,6 +16,7 @@ #define sv_fp v5 #define sv_pc v6 #define offset v8 +#define loglvl v9 ENTRY(__backtrace) mov r0, fp @@ -27,10 +28,11 @@ ENTRY(c_backtrace) ENDPROC(__backtrace) ENDPROC(c_backtrace) #else - stm.w (v4 - v8, lr), [sp-] @ Save an extra register + stm.w (v4 - v10, lr), [sp-] @ Save an extra register @ so we have a location... mov.a frame, r0 @ if frame pointer is zero beq no_frame @ we have no stack frames + mov loglvl, r1 1: stm.w (pc), [sp-] @ calculate offset of PC stored ldw.w r0, [sp]+, #4 @ by stmfd for this CPU @@ -95,9 +97,10 @@ for_each_frame: bua for_each_frame 1006: adr r0, .Lbad - mov r1, frame + mov r1, loglvl + mov r2, frame b.l printk -no_frame: ldm.w (v4 - v8, pc), [sp]+ +no_frame: ldm.w (v4 - v10, pc), [sp]+ ENDPROC(__backtrace) ENDPROC(c_backtrace) @@ -128,8 +131,11 @@ ENDPROC(c_backtrace) add v7, v7, #1 cxor.a v7, #6 cmoveq v7, #1 - cmoveq r1, #'\n' - cmovne r1, #' ' + bne 201f + adr r0, .Lcr + mov r1, loglvl + b.l printk +201: ldw.w r3, [stack]+, #-4 mov r2, reg csub.a r2, #8 @@ -141,18 +147,20 @@ ENDPROC(c_backtrace) add r2, r2, #0x10 @ so r2 need add 16 201: adr r0, .Lfp + mov r1, loglvl b.l printk 2: sub.a reg, reg, #1 bns 1b cxor.a v7, #0 beq 201f adr r0, .Lcr + mov r1, loglvl b.l printk 201: ldm.w (instr, reg, stack, v7, pc), [sp]+ -.Lfp: .asciz "%cr%d:%08x" -.Lcr: .asciz "\n" -.Lbad: .asciz "Backtrace aborted due to bad frame pointer <%p>\n" +.Lfp: .asciz "%sr%d:%08x " +.Lcr: .asciz "%s\n" +.Lbad: .asciz "%sBacktrace aborted due to bad frame pointer <%p>\n" .align .Ldsi: .word 0x92eec000 >> 14 @ stm.w sp, (... fp, ip, lr, pc) .word 0x92e10000 >> 14 @ stm.w sp, () |